Fiat Ducato

I'm going to cover two problems here. One is fixing the fridge and the second a really serious matter concerning the gearbox.

I thought I'd pen a few lines to show how I've maintained my Fiat Ducato, especially the campervan version, and here only in areas of untypical maintenance. Our camper was made by a company called Adria having been modified from a standard van built in 2004/2005. The date is fairly important because not long after that date various changes were introduced making spare parts often tricky to identify correctly.

Fixing the Fiat Ducato Adria Campervan Fridge

Quite recently (May 2024) our fridge stopped working and I had to figure out how to fix it. It's powered from a choice of three sources.. 240 Volt AC mains, 12 Volts DC or gas and, since we've owned the van (from 2007), it's been plugged into a mains supply and quite naturally the fridge has been using that option. Not too surprising then, after 17 years of continuous use, that the mains option failed. Thinking about the reason... the heater whose task is to keep the gas-liquid refridgerant cycle running will have been turning on and off so somewhere in its construction metal fatigue probably eventually open-circuited the element.

I checked and found that suitable new elements were plentiful so bought one and fitted it. The fitting exercise was not straightforward as it meant deciding how to remove the old element and insert the new one. Not only swapping the actual element posed a problem.. but how the fridge fitted into the van needed to be figured out. The pictures below show how I managed.

One of the clues to fridge failure is the lack of waste heat leaking from the upper grille. When the fridge is working normally one should be able to feel a waft of warm air if you put your face near to it.

Removal of the fridge for repair involved several stages of dismantling. The first step having diagnosed the fault was to remove the exterior grilles. These were clipped into plastic frames secured with stainless steel screws. I found much better access after also removing the frames.

The second step was to detach all the electrical cables and the gas supply pipe. The cables are on the top and the gas supply pipe connection is at the bottom left looking from the rear. This was better accessed once the fridge had been slid forwards about six inches or so.

Limited access to the wiring was via a detachable panel in the floor of the wardrobe so I was able to test heater supplies and their continuity. In my case, as I'd expected, the mains heater proved to have failed requiring the removal of the fridge.

After a lot of puzzling I found a pair of fixing screws located behind the passenger seat. These were holding the fridge in place in conjunction with a kind of very messy black Bostik.

I was then able to shift the very heavy fridge and this picture shows it slid forward with its door removed.

I identified the screw connectors holding the various cables which needed to be detached.

Basically these are the mains input, the battery supply and the thermostat wiring.

I made notes and took numerous pictures of how these were routed and to which choc-bloc terminals the cables connected.

Below, after the gas pipe (bottom right) and the cables had been unscrewed, I pulled out the fridge and lifted it away to gain access to the heater assembly. I lifted it onto the adjacent seat, taking care not to get any Bostik on the seat material, and using the inspection panel from the wardrobe floor on which to rest the fridge on the seat.

Here you can see the electric heater assembly.

There are two heaters within the heavily insulated metal sleeve. To gain access meant unclipping the outer sleeve and pulling away some of the insulation material, after which the mains heater was jiggled out. The battery powered heater, fed by the grey cable, was left in place.

On the left is the open circuit heater and below is a picture of the replacement heating element.

Fitting the new heater and refitting the fridge was fairly straightforward and it then worked normally.

Now I'll describe a really nasty gearbox problem

Note: This job which would have cost more than £3,750 directly resulted from several pennypinching design changes will befall lots of owners of the Ducato, Boxer and Relay vehicles.

Our campervan hasn't seen a lot of use. A mere 20,000 miles in the last 20 years so faults that may occur may not be particularly common. Recently, we drove to Cornwall, probably around 400 miles round trip. The van behaved perfectly for 398 miles before it suddenly stopped in second gear after changing up from first. No amount of pushing and pulling the gear lever would shift it from second gear. As we were in a huge traffic jam on Avon Causeway I needed to do something and quickly discovered I could make way by slipping the clutch and making headway but at no more than 20mph. The last two miles, using hazard flashers brought me to our gate and by pure luck managed to get through with inches to spare without scraping anything.

After puzzling over the fault and coming to the conclusion the van was stuck in the drive (reverse gear impossible) and we needed to repair it unaided. The problem could have been caused either by a seized gearshift mechanism (we'd had this problem a year ago but geasing had fixed it) or damage inside the gearbox such as a broken part jamming the gear selectors.

There was a tiny clue. About 50 miles from home, changing from third to fourth, I think it was, there was a slight graunching noise and minutes before the gearbox had locked up a similar noise was heard. Could the cause be a fractured selector fork which had finally given up and broken?

A view of my Fiat Ducato soon after my son Jeremy, only slightly helped by myself, started dismantling the parts necessary to get to the gearbox. This started with the starter motor and at that point we realised that all the bolts were going to be extremely difficult to remove. A year or two ago, in order to get through the MoT test I'd swapped the front brake disks and pads and found it impossible to shift the caliper securing bolts with my tools. Since then, for other purposes, I'd invested in an impact wrench and this proved to be our salvation. We were able to remove enough bolts in order to loosen the gearbox from the engine.

All was not well however because the gearbox would move only a couple of inches from the engine. After puzzling over this problem for ages we stumbled upon a report about our specific version of gearbox assembly. For esoteric reasons, which I understand were soon abandoned, the clutch release mechanism is secured inside the bell housing by a shaft which extends outside the casing so it can be removed. The end of the shaft has a groove around the perimeter so a "special" tool can be used to remove it. Alas, like other parts (which had suffered from corrosion due to standing water) the shaft was completely seized. The special (expensive) tool succeded in removing the end of the shaft, leaving the remainder securely in place.

Why is this shaft so difficult to remove, even with the special precision tool, you might ask?

Well, it's due to a design fault... but nothing to do with this clever method of reducing clutch/gearbox noise.

The error was to fit a rubber tube for rainwater from drain channels which was too short. The rubber tube ends just above the gearbox and allows water to pour onto the flattish gearbox top.

As you can see here there's even a cavity around the shaft which fills up with water. This picture was taken after I'd removed most of the white aluminium oxide corrosion residue.

The shaft being steel and the hole being aluminium means that the shaft is virtually welded in place.

20 years of corrosion!

Below, at this point I'd removed most of the aluminium oxide surface corrosion, but you can see it's still pretty horrible.

How on earth can we remove this shaft? At first we were stumped, but...... other people had reported another method. This was to drift out the shaft from inside the bell housing but this required a hole to be drilled in exactly the right place. I didn't fancy this idea and in fact it's easy to break the aluminium casting close to the point where the shaft protrudes.

So.. what's the solution? Well another intrepid repairer had come up with a much better solution. This may have been Fiat's last resort method, or merely a stroke of good luck... who knows?

At the bottom of the gearbox is an inspection hole (shown below) and by levering the bell housing away from the engine to its fullest extent... a couple of inches... it's possible to see the bolts securing the clutch assembly to the flywheel. There are four pairs of 6mm hex screws and by inserting an Allen key with a longish handle each bolt can be unscrewed. To do this means turning the pulley at the front of the engine using a very long extension bar with a largish handle as the engine is not only stiff to move but the tilted bell housing is fighting against any movement. However this is quite an easy job. First the Allen key is used to break the seizing and then, because of limited access that Allen key needs to be replaced with a shortened one. This was easy enough, using an angle grinder to cut about ten mm from the short end. This modified Allen key can then be used to fully loosen each screw until the gearbox falls away and can be withdrawn, complete with the clutch mechanism and friction plate. The whole assembly is very heavy.

During manipulation of the gearbox a plastic fitting broke. As the gearbox could rotate relatively freely a protruding part of the casting struck a fuel pipe where it enters a multi-way block on the back of the engine. Alas, this is a complicated and very expensive part. Being a weak plastic part you'd think that Fiat would supply just the multi-way block.. but it seems not.

Here's a view of the inspection hole in the lower part of the bell housing.

At least there are no corroded screws securing a protective cover to remove as there isn't one.

With the gearbox on the bench you can see the huge amount of corrosion on the upper surface compared with the lower part. You can also check the operation of the gear change lever. This should rotate and/or pull out or push in quite freely. Ours moves only less than half an inch in any direction. It's free to move so not seized but clearly something is restricting its movement. My guess is a broken part is responsible.

That odd shaped lump of metal with a ball is a counterweight to assist in gear changing and after viewing a vlog I can report that it's a very brittle steel casting so don't attempt to detach it. It isn't necessary anyway.

You can see rust on that shaft so that's something to rectify and grease later.

Below, a couple of views of the gearbox on the bench (upper surface followed by underside). Clutch lever bottom right.

Above you can see the "captive version" clutch mechanism. It uses an operating lever anchored to a seized shaft mentioned previously. I believe that by poking at that centre release bearing one can jiggle the parts free. As our clutch was fine and has little wear all this will remain in place. On the left is the hole for the nearside (passenger side) driveshaft.

Below, after cleaning away a lot of aluminium corrosion we removed the top cover. This is secured by a set of T40 screws and the cover is securely "glued" in place requiring a lot of hammering and levering with a large screwdriver.

Below, after detaching the cover you can see the gears responsible for the fifth gear on my 2.3JTD.

Poking out the top right are the ends of the three shafts used for holding the gear shift forks.

The hole for the offside drive shaft (centre right) is protected from dirt ingress. The area on the right is the differential gearing casing and will be left alone.

The next step is to remove these top gears and withdraw the casing to expose the main gear trains, but first we'll need to detach the three ident springs with their ball bearings otherwise the latter will be ejected and probably lost. This is were we met a very tricky problem. The screws holding the ident parts in place are Torx and are sunken in holes which of course, over the years had been full of water resulting in really bad corrosion. Because of the position of the gearbox I hadn't seen how bad this was and selected a Torx T30 bit that fitted snuggly. Unfortunately, although this was tight initially, under some force it then spun uselessly. I turned the gearbox so I could see more clearly and found so much corrosion it had removed the top surface of the steel screws thus reducing the strength of the Torx aperture. After cleaning away corrosion residue a T40 bit almost fitted in the two shallow holes and fairly snuggly in the deep hole (left.. below). The Torx indentations were shallower than original because the upper surface of the steel screws had corroded away. My Torx bits have a slight champher resulting in less penetration so I ground this away to give me a flat end. Tapping the bit with a hammer into each Torx hole resulted in a tight fit so with luck I can now remove the screws. The problem is similar to the seized clutch shaft (also due to the poor design of rainwater extraction) where the steel/aluminium contact area is badly corroded and resulting in a kind of welding.

Above, a view of the three screws which secure the springs and ball bearings for click-stopping the gear lever. As I explained they're completely seized and, despite being very careful, a T40 Torx bit failed to release the two on the left (below) ending up with roughly circular graunched holes. I initially drilled small holes at the outer edges of the screws to produce a widish slot but the screw still failed to budge using a ground down chisel fitted to my impact driver. So, next we drilled a hole through the left screw and tried a stud extractor but this also failed. The final (successful) method was to deepen the slot using a small drill and then use a wide screwdriver bit, slightly ground narrower to clear the aluminium housing, in the impact wrench. This worked and the two graunched screws loosened. Thankfully the rightmost screw loosened with a T40 Torx bit, again using the impact driver.

Right, three new plugs. These are very popular with designers because they're used on lots of current models of car.

Here's a useful fact.. the ball bearings used in the ident mechanism have a diameter of 7.5mm.

Below, the condition of the old screws after they'd been loosened.

It was now safe to tackle the top casting carrying the 5th gear selector and gears. All the securing screws, whether Torx or standard bolts needed the impact driver as most were corroded.

The Ducato gearbox has its four forward and reverse housed in the main casting with the fifth gear fitted under a steel cover screwed to the top.

There's a stock fault very common to the fifth gear and it's possible to access and repair this problem with the gearbox in-situ. Mine is OK.

However, to repair a general fault the whole gearbox assembly, including the bell housing, must be removed. In the case of my version of the Ducato the clutch assembly is fitted into the bell housing in such a way as to make it virtually impossible to detach. See previous comments.

Once the box is removed the fifth gear assembly can be detached as shown above and opposite.

Within this assembly is a spring clip which I shall later exchange. Read on.

Below, now that the casting has been pulled off, the main gears, layshaft and reverse gears can be seen.

Here are three views of the main gear assemblies visible once the aluminium casting has been pulled off.

The smaller reverse gear can be pulled off by jiggling it, then the selector mechanism needs to be detached, mainly by jiggling it until it frees up after removing its six Torx securing screws. The process is easier if the peg (shown) is pulled out.

At this point we decided to try and locate the fault which was jamming the gearbox in second gear.

By trying to move the gold-coloured selector arms by hand we could see a section of spring sticking out from the gears preventing two of the gears (low down on the shaft) from unmeshing.

It's interesting to note that if one used excessive pressure on the mechanism the dislocated spring might be encouraged to slip back into the slot or even be broken off. Two possible things would then occur. One is that part of the (gold coloured) selector arm could snap off or secondly any freed broken spring parts would jam the main gears. In either case significantly more damage will result.

Below you can see a good view of the protruding spring.

To replace the bad spring the entire set of gears needed to be detached from the shaft commencing with the top nut. This nut has a shoulder which was punched into a pair of slots in the top of the shaft. The punching needs to be reversed so the nut can be turned. Once the nut is free to rotate it can be simply detached using a 36mm socket fitted to an impact wrench.

At this point you have a problem. There's a bearing pressed onto the shaft and there's very little clearance (approx 1mm) to use a standard puller. There's a type of circlip fitted around the bearing and this may be for helping to pull the bearing free? In fact the official way of detaching the bearing is to fit a puller under the gear immediately below the bearing. In the event we didn't have any tools for that method so we made a simple puller to do the job. We started by using two very thin metal plates (about 1.5mm thick) which were tapped into the space below the bearing. This was only possible by grinding the leading edges of the plates so they gradually levered up the bearing when tapping in. We then used a couple of L-shaped pieces of metal (for strength), slightly thicker (about 2mm) and again ground to a champher to make a tight fit under the bearing. Tapping these into place enabled us to move the bearing up the shaft a mm or two for sufficient clearance for thicker metal plates. We used whatever material and bolts that were to-hand so things are certainly not pretty. Pictures below.

Once the bearing started to shift upwards we were able to use more sturdy material. The next picture shows a failed attempt due to weak material and below this the successful puller.

You can see we had trouble finding suitable junk box bits and pieces and that some design changes were clearly desirable, but the puller did work and the bearing finally popped off. This was quickly followed by most of the gears. Picture below, arranged as they came off.. bottom right, clockwise.

And finally, here's the culprit.

The last securing clip was removed and the last set of gears detached to reveal the broken spring.. below.

Why did this spring fracture after only 20,000 miles ?

Well, this event is not uncommon because there are countless replacements on sale. Also there are plenty of vlogs regarding Fiat Ducato (plus similar Peugeot and Citroen badged vehicles) describing gearbox failures which can mostly be traced back to bad springs.

There are two versions of this spring viz. Fiat parts 9645385880 and 9645385980. The gearbox in my 2.3JTD uses three of the first part (opposite) and two of the second. I'm expecting a set of these five to be delivered in an hour or so (6th August 2025).

As I passed my GCE Metalwork exam (back in 1958) with flying colours I can explain (roughly) how these springs are made.

Given a superior quality carbon steel wire, a length is cut and shaped. The metal is then heated until it has reached a specific temperature then quickly quenched to produce a hard brittle finish. The heating is then repeated until a second critical temperature is reached. The metal is then quickly quenched resulting in a springy finish.

The temperatures involved are really critical and of course the quality and specification of the raw carbon steel is especially important.

If either the raw steel wire and/or the manufacturing process is not perfect the spring will fail to meet its design target life. The steel composition is absolutely vital. If an unsuitable or cheap alloy is used, say to cut costs, the end result will be a horrendously expensive gearbox repair.

As a matter of interest I've contacted

"Customer Care" at Fiat for any feedback on this spring failure after a mere 20,000 miles together with any comment on the rainwater pipe positioning.

Well, I can report that Fiat "Customer Care" were totally useless and should be renamed "Fiat couldn't care less".

For general interest I've shown a drawing of the contents of the main reduction gear shaft below with numbers in red to indicate their removal sequence and identification later.

Right.. the set of relacement springs £42.13

Removal of nearly all these parts is necessary to access the broken spring (Part 25). There are four springs mounted on this shaft, the topmost being a Type 14 marked 14-C above (Part 9). Parts 15 to 8 at the top of the drawing are for fifth gear and located in the section on top of the main casting and covered by a steel cover.

Once these (fifth) gears are detached, plus a C-shaped ring securing the top mainshaft bearing, the main gearbox casting can be pulled off exposing three shafts; the reduction gears shown above plus the layshaft (which I'm not dismantling) and reverse gear parts (I'll be swapping spring 14-D). Summarising, the only parts needing replacement are the five springs. One Type 14 is buried in the fifth gears plus a second Type 14 (Part 9) and three Type 13 springs (Parts 11, 23 and 25) which are located on the main reduction gear shaft.

The various parts in the drawing are supplied in sets as shown in the lower-left picture listing A-D whose grey numbers relate to the parts list below.

Examination of the parts removed from the shaft suggest that A to D (the synchromesh parts) contain some common parts viz. the three ring-shaped items. You'll note that B (the sync parts for 1st/2nd gears) are fitted so they're facing. This is the same for C (sync parts for 3rd/4th gears) so it's important to fit these the right way round!

Looking at the parts listing below you'll note that some parts which look identical have different Fiat part codes so will presumably not be interchangeable.

Having received the new springs I'm ready to begin reassembly of the reduction gears onto the shaft so studied the parts drawing (above) to check I knew which way round the parts fitted.

As I also have an eLearn document describing the process of dismantling and reassembly I decided to read this for any extra advice. I was then very puzzled because the drawing of the synchronisers was totally different to the parts I'd removed.

The accompanying text said to take care to remove the "balls" and the drawing showed an arrangement very like the gearchange ident mechanism with a springs and ball bearings. Also the strange three-legged gear has not three but six legs. It seems that there are two different synchroniser designs. My initial document mentions the "Nuovo" Ducato... so, did the designers change from an "ident" method to those circular springs with those protruding sections? Surely the simpler spring design reduced the overall cost of making the gearbox? If so then spring reliability let them down (maybe their sub-contractor was sloppy?).

Cost saving maybe £20 per vehicle. 100,000 vehicles saves two million quid. Fiat plus Peugeot plus Citroen.

Above you can see how I fitted two of the new springs. When the gears were removed one spring was stuck inside the annular gearwheel. Using logic and hopefully getting it right I wedged the springs into place as shown inside that three-legged gear. Below are two views of the assembled shaft without the bearing.. I'm sure I've got the assembly wrong because there's insufficient space to fit the bearing and its impossible to move either the upper or the lower fork ring.

The shaft has three identically-looking sectors and these two pictures show views which are 120 degrees apart. The right hand end fits into the casing where it mates with the differential gear. Note that the bearing should slide onto the plain section of shaft at present taken up with the top gear. The topmost gear with the special nut fit onto the bearing then protrude above the gearbox case once this has been fitted. I won't fit the bearing until I'm completely happy with the assembly.

This reassembly was wrong in two ways. First the brass coloured partly toothed ring Part 8 should have been pressed into the annular fork ring. Secondly, I hadn't noticed that the lower annular fork ring has raised sections on the internal grooves that are not too obvious and these must be positioned to coincide with the positions of the jutting out parts of the circular (Type 13) springs otherwse these raised sections prevent upwards movement of the fork selector ring. Below are pictures of correct assembly. First the top fork selector in its two positions. Ignore their incorrect location on the main shaft.

The picture on the right shows the uppermost part-toothed ring pressed into position in the fork selector annular gear.

Below is the underside view of the uppermost assembly opposite

Here are more views of the various sub-assemblies fitted on the shaft.First the 1st/2nd gear mechanism mounted on the bottom of the shaft.

When correctly assembled, pulling the selector ring upwards or pressing downwards should produce a sharp click either side of centre neutral. You can see that one side of the selector ring has missing teeth defining three 120 degree sectors.

Note that the lowest gear on the shaft is 1st (cog 30), followed by 2nd (cog 18) plus their selector. These are followed by 3rd (cog 16) and 4th (cog 6) with their selector. 5th gear selection is carried out in the add-on part enclosed by a steel cover whilst reverse is handled by a gearwheel mounted on a swinging arm which allows engagement or disengagement from neutral.

1st/2nd gears. Top ring deselected (3 x 11 teeth)

1st/2nd gears. Top ring selected (3 x 11 teeth)

The pictures below show how the 3rd/4th synchromesh gears are arranged.

Visible on the underside of the 3-legged gear, below left, you can see a Type 13 spring wedged in place.

Bottom left, a Type 14 spring held in place by the 7-toothed gold- coloured ring which is fitted in place below right.

1st/2nd synchromesh gears use a pair of Type 13 springs wedged in place on their 3-legged gear as shown bottom right.

Having proved that both selector rings are able to be set in their upper, neutral and lower settings I can now reassemble these on the shaft.

Pictures below show the assembled gears in various settings before the upper bearing is pressed home. I need to compare the gear positions with those on the layshaft to check everything's OK. This shaft in isolation, with the operation of each of the two selector rings (later connected to forks and three settings governed by their ident mechanisms) can be set to any one of 24 combinations through the choice of: 1st, neutral and 2nd. 3rd neutral and 4th.

Once fully installed with interlocks these combinations reduce to only five

viz. 1st, 2nd, 3rd, 4th and neutral, and with the other gears adding 5th and reverse.

Before gearbox reassembly I'll tackle the horrible corrosion caused by Fiat's slack designers who'd arranged for rainwater to be sprayed onto the gearbox.

Finally, after matching the gear positions to those on the layshaft, I fitted the bearing (Part 4) with its shim (Part 5). Rather than hammer it into place I used a spacer (a jubilee clip) with a pair of washers and just screwed down the nut (Part 1) until it bottomed out. This required my impact driver with a large 36mm socket because the shaft is free to rotate and a lot of force is needed (the nut measures 36mm across its flats). It's vital to set the bearing correctly in place (which is tight against the shim), as later when fitting the casting, the C-shaped securing clip should be a precise interference fit in that upper groove in the bearing.

Next I cleaned up the damaged threads in the ident mechanism holes. The depth from the casing to the ledge which stops the screw's tubular end section varies for the three from 21mm to 18mm.

The new screws with their ball bearings and springs will be fitted once the three associated shafts are in place.

But now I've come across a problem.. One needs at least 3 hands and preferably four to reassemble the main parts. The main shaft, layshaft plus the two gear shift forks need to be placed in their correct positions simultaneously and they wobble around freely, and they're quite heavy.

The forks cannot be fitted independently but must be engaged with the selector rings as shown in the pictures below.

The pictures above show... firstly the main and layshaft placed in their correct positions, secondly the gear shift forks also fitted then the four assemblies fitted loosely together, then the holes through which all four must locate correctly at the same time. One method might be to fit these four assemblies into the upper casting then upend the bell housing and jiggle it into position. Once this has been done upend and carefully remove the casting. This would mean manipulating the heavy bell housing with its captive clutch assembly. I found the best way was to make a template from strong card with the four holes (shown above) precisely marked from the upper casting, place a couple of securing straps around the four assemblies, locate the template over the shafts then wiggle the whole thing in place.

The method was successful and I left the template in place so I could check gear selection was OK. I used six tie wraps to keep the two gear shafts together. The template was made by marking stiff card from the top of the gearbox upper casting then cutting the holes with scissors. A small paper template made it easier to locate the two selector shafts.

This picture shows the four assemblies in position. Next to be fitted will be the reverse gear selector shaft, reverse gear with its axle and the selector mechanism. The latter is shown below. Note that there's a locating peg on the underside of the mechanism.

Fitting the additional parts is a bit tricky and a fair bit of wiggling around may be necessary to fit everything properly. For example here.. I hadn't noticed that I'd forgotten to locate that selector shaft peg through the hole below the normal operating position. I only noticed once I'd had trouble locating the selector assembly whose fixing screws were too tight. See below.

Note that one needs to temporarily remove a pin (shown below) otherwise its impossible to fit things back in place. I'd replaced the pin during disassembly to avoid losing it and it's well nigh impossible to complete the assembly without temporarily removing it. The pin is located in the U-shaped bracket (right). Once this has been removed things are easy to fit.

Here's a sting in the tale. As I added more of the parts from the pile left over I picked up the 5th gear assembly and spotted the synchromesh spring (seen through those three apertures) was a funny shape. You can see on the left a view after a new spring had been fitted and the old spring on the right. For some odd reason two springs in the set of 5 in the gearbox are like this one (Part 34, a Type 14 spring) and held captive in their brass (Part 35). Ref the drawing above. Whether the broken spring would have been released from its mounting like the broken Type 13 I can't say, but it's clearly either a very serious design error, or a significant fault in the spring manufacture. I should really tackle Fiat once more about this. After a mere 20,000 miles this problem should not have happened.

Left, the repaired 5th gear synchromesh assembly. Below its broken spring (Fiat part 9645385980).

This is the 5th gear synchromesh assembly temporarily fitted so that I can test its operation before refitting the top gearbox casting. You'll note the hole for securing the fork to the shaft will need to be fitted once the casting has been put back.

Below, a trial fitting of the casting before using the sealant.

The casting is an "interference fit" making it tricky to put back in place. For example the casting close to the top of the layshaft fits underneath the top gear and removal of the casting because of this is not straightforward. You may notice a Torx ident bolt is still fitted from repairing thread damage. The springs and balls are not in place yet. A set of three new bolts will be used.

I'd noticed on disassembly a small circularish rubber ring dropped onto the bench (Number 19 opposite) which fits on top of the plastic oil feed (Number 8 opposite). This oil feed is just held in place by its two clips close to the reverse gear selector mechanism.

As the casting is pressed into position using a rubber mallet a few internal parts need to be located so they slip into their mating holes. The main gearshaft upper bearing is a tight fit in the casting. I measured the height of the bearing up to its circlip and this is 17.1mm. The casting thickness is 12.4mm so the top edge of the bearing will protrude by about 5mm from the upper surface of the casting.

Above... The reverse gear ident mechanism is different to that for other gears and need not be removed during disassembly. The ball at its end automatically locates in a hollow in the lever. Also the reverse gear switch can be left in place as the end slides into place down the selector lever as the casting is replaced. The union covered by the black plastic cap is used for filling the gearbox with oil.

The final steps in reassembly were to fit and tighten down the upper casting, fit the 5th gear synchromesh assembly, pressing home the pin securing the selector fork to the activating post, and fit the clamp for the mainshaft together with the large nut. Two points of note: in order to prevent impact damage to the cast fork I used a mole wrench to squeeze the pin in position. The large nut was tightened by hand then tapped a few times with a punch to tighten it.. then the punch was used to bend inwards the rim of the nut. Also note that the gap between the main shaft top bearing and the casting only opened sufficently to insert and bolt down the C-shaped locating tab once the set of securing bolts was fitted and fully tightened. Also, the lay shaft roller bearing remained very slack until all the bolts had been tightened. Note that there's a tiny rubber seal (part 19 in the drawing shown previously) that fits over the plastic oil distribution tube (part 8).

Once completed everything seems to work as it should and I did remember to remove the magnet and clean this before refitting it.

I used a tube of Reinzosil for applying the seals between the bell-housing and the upper casting plus the top cover.

Below, views of the reassembled gearbox.

Above... an amazing improvement when painted.

Below, where the overhauled gearbox needs to go back.

Note the 8 hex bolts (in 4 pairs) around the flywheel. These will be removed then carefully reinserted via the bell housing inspection hole to secure the clutch.

Before we'd discovered the abyssmal design of the clutch assembly the gearbox twisted around and snapped a fuel line. Yet another design weakness.. the clutch operating lever pivots on a shaft across the inside of the bell housing. The design is very bad because the shaft is an interference fit through the aluminium casting and after a few years the shaft is impossible to slide out. There's a special tool made for the job, quite expensive and absolutely useless because all it does is pull away the steel lip on the end of the seized shaft. Some say that the best method of removing the shaft is to drill a hole in the bell housing opposite the far end of the shaft and drift it out using a punch. This might work for some, but for others you end up breaking the aluminium casting. Fortunately another recommendation is a much safer method which is to unscrew the clutch assembly from the flywheel via the inspection hole in the bottom of the bell housing. This worked fine but before we'd discovered this method the gearbox had spun around and broken a fuel feed pipe which is terminated on 4-way adaptor mounted on a plate adjacent to the bell housing (in fact the adaptor is 5-way not 4-way as the documentation describes it).

The damage was to the male part of the lower of two quick release connectors. It just cleanly snapped off the 4 way adaptor. At first sight one needs to buy a complete fuel line assembly at upwards of £250.

Initially I thought the 4-way adaptor combined four pipes in a manifold but after taking pictures of the thing it seemed the 4-way adaptor had two separate functions. Firstly it serves to connect the fuel tank via a filter to the fuel pump. Secondly it connects the fuel return pipe from the engine to the tank. However after more detailed scrutiny it seems a pressure relief valve marked "Dayco" connects the two pipes.

The pictures below are not exactly definitive. That shiny screw (top right picture) is to close off any diesel leakage and the broken pipe has been strung up to prevent the tank from draining. Top left you can see the name "Dayco" on the pressure relief valve.

From the two drawings below it's the feed pipe from the fuel filter (marked "2") which is broken off. A possible solution, assuming the broken part can't be glued back, is to seal off the entry (currently this is done with a screw) cut the nylon pipe to the fuel pump and insert a three-way adaptor. The pipe from the filter can then be connected to the adaptor. That still allows fuel from the relief valve to recirculate. The adaptor will have an 8mm through path and a 6mm junction. This is Option 2.

Ducato 2.3JTD fuel system (2005)

Spare part: 504088126

Just a few bits to re-install.. plus the air cleaner, starter motor and lots of pipes to reconnect. Then fill the gearbox with oil and reassemble the gear lever and various dashboard items removed when diagnosing the problem. Finally the front wheels.

At this point I decided to fix the damaged fuel line. One option is to heat the plastic fitting and weld in place either the broken piece or a new brass fitting. As this means lying under the van with a hot air gun to heat the plastic fitting I checked on the ignition point for diesel fuel because the pipe was pretty wet. I discovered that the temperatures involved would make it very dangerous to tackle with the fitting in-situ. The plastic is PA66 nylon and has a melting point of 260C whilst diesel fuel ignites at 210C. Using a blanking screw as I already tried successfully means cutting and inserting a T-piece in the tubing. This also requires a measure of heating. The options therefore reduce to screwing a suitable connector into the hole in the fitting or removing the fuel pipes. The latter was the better option but alas this was much more tricky than we'd imagined.

The fuel pipes are held inn place by four banjos but one uses a 18mm bolt with a flexible pipe secured to its head. One can only loosen the bolt about half-way due to tension in the pipe so we had to detach the pipe. The better option was to leave it connected at the bolt head and release the opposite end, but this connects to the fuel injectors as shown below. After unclipping these injectors the bolt was removed.

The other three banjo bolts were easy enough to remove and with a lot of wiggling the fuel pipe was detached.

To prevent the fuel tank from emptying under gravity the quick release pipes were wedged higher than the tank as shown here.

Below, the device marked "Dayco" has markings which are not part numbers but codes indicating the nylon material eg. "PA66" which is the grade of nylon. The top part is flexible and the body pretty hard. The break is shown on the right. The hole is 5mm in diameter and I'd used an M5 bolt with some polythene to blank it off. It seems a reasonable idea to thread the hole for an M6 screw. The thread depth available measured at 11mm to 12mm up to the hole from the valve.

After attempting to make an adaptor suitable for inserting into the hole (above right) and running into trouble I found a seller offering a collection of varied brass fittings whose design looked ideal for the job. I chose 15mm of thread to fit the 12mm available and a pipe fitting that will be suitable for fixing the feed line from the filter. I now need to carefully thread the hole for M6. Note: Threaded barbed adaptors didn't have enough thread (less than 8mm).

Once fitted I'll take a view on whether to add Option 2, a 3-way adaptor, as backup.

Failed!!

Why did my plan fail? The reason might have been obvious. Although the picture in the group of three, above right, shows a M4 tappable hole, when I tried this the thread length was a mere 1mm (the thickness of that reinforcing ring). After that point the hole measured 6mm (ie 8mm tube with 1mm wall thickness). I realised that I could make do with the piece of broken tube as this was OK for threading at 8mm if the hole in the fitting could be tapped to suit. In fact, because of difficulties in tapping the flexible nylon, this would only work if I drilled the hole from 6mm to the recommended 6.8mm (for M8). Luckily I had a 6.8mm drill and after enlarging the hole, I was able to tap it using a tapered tool.

Threading the broken plastic tube for 8mm was tricky as it needed a critical pressure to hold it in place, but it worked and I managed to thread about 10mm or so. The final step was to fit the threaded tube and to do this I needed copper grease to overcome friction. Because of elasticity in the plastic the M8 thread on the tube was oversize and the hole thread was undersize. I used a pair of pliers to tighten the tube (remember that not only were the threads slightly off-size the far end of the tapped thread was tapered). The end result is a lot stronger than the original but the quick release ring is missing so I'll need to cut off the quick release plug and use a linking tube fitted with a tapered brass 6mm joiner. Note that I did remember to empty the tube of plastic swarf before screwing in the tube.

I could of course used a larger M8 brass fitting like the one shown above but that might have needed plumbers tape to reduce the chance of leakage.

Now that the tubing is restored the gearbox can be refitted.

Fitting the new pipe was slightly complicated as I didn't want to damage the repair. I fitted about 12 inches of 8mm extension pipe to the threaded tube. The extension is a hard nylon of 8mm overall diameter (essentially 5/16 inch) and around 6mm internal bore. The plan was to join this to the original pipe using a barbed adaptor carrying a male quick release fitting compatible with the original. Refitting the pipe assembly involves securing its four banjos, with one that needed the fuel injectors unclipping, screwed into place allowing the fuel injector feed pipe to rotate freely. Once the final banjo was tightened the four injector pipes were refitted and clipped int place. Note that the pipe assembly which needed a lot of jiggling to detach needs to be fitted as it was originally... an exercise requiring a few attempts.

One of the difficulties met during dismantling of parts in order to access the gearbox was the air cleaner securing bolts. These are rubber shock mounts (right) and, because their securing nuts in the base of the air cleaner box are too corroded to remove without breaking them, putting back the air cleaner requires new mounts. These are used in many versions of the van but for my 2.3JTD of 2005 the Fiat part number is 7657109 and it's called a "Pad". Prices vary but can be as much as £40 for a set of three. After a little hunting around I discovered these much cheaper alternatives....

These originals are threaded M6

New air cleaner mounts fitted and new filter, left.

Putting the air cleaner back will involve a lot of manipulation due to limited space.

Now.. refitting the repaired gearbox

Getting the gearbox into position is quite difficult in one respect but slightly easier in another. The easy bit is because the clutch mechanism is carried inside the bell housing so doesn't need a centering mandrel. The major problem however is that the clutch mechanism which needed to be unbolted from the flywheel whilst remaining captive inside the bell housing makes reassembly extremely awkward in two respects.. firstly the clutch needs to be located on three flywheel pegs before it can be bolted onto the flywheel and this isn't easy. The solution adopted was to fit the clutch activating plate making it possible to press the clutch pedal to ease the clutch plate off the back of the flywheel. Once freed, the engine can be turned so that the pegs can be located, then the six securing screws can each be fitted using the shortened Allan key via the inspection hole..

In the event, fitting those six hex screws was incredibly difficult. The main problems being the very limited access through the inspection hole (which is probably so you can see clutch wear rather than access those screws) and misalignment of the plate and flywheel. To make progress we had to free the bell housing and withdraw it back about 10mm. That reduced the pressure between the parts allowing us to line up the nearest peg but, because the parts were misaligned, the hex screws couldn't be screwed into place because the extra 10mm clearance meant the screws were too short. A slightly longer temporary M8 bolt (bottom left) was used instead which, after a lot of fiddling getting the thread to line up and bite, managed to pull the plate closer to the flywheel with the local peg in its hole. Then, turning the engine via the front pulley nut enabled a correct hex screw to be inserted (bottom right)...again with great difficulty to align the threads and using an Allan key cut to the minimum length of a few mm inserted into the gap and twisted into position. Then, after fitting the pair of screws the engine was turned about 120 degrees so the next screw could be inserted. The remainder followed, with the initial bolt finally being removed and the proper hex screw inserted. As each screw was inserted and tightened, the engine rotation became freer as the plate and flywheel took up their correct postions. The exercise took about two hours in pouring rain. The last step was to close the 10mm gap, drawing the bell housing into place, and then finally fully tightening the six hex screws.

This tricky method of assembly was only necessary because the clutch mechanism was frozen into place by corrosion. We could have attempted to free this but previous attempts by others had broken the gearbox mounts on which the clutch release mechanism slides. A possible easier solution is to enlarge the inspection aperture, perhaps by an inch or so. This would enable the job to be done more quickly at the expense of weakening the casting.

We're not the first to complain about rain falling on the windscreen of the Ducato being dumped onto the top of the gearbox. In fact, with the drain tube correctly positioned to clear the gearbox (it hadn't even detached itself from its weak clip) I noticed that the hollows in which the Torx gear idents are fitted were full of water. Then I noticed a steady dripping from the point where the top of the rubber pipe is clipped. This wedges into a well behind the black plastic grille on the passenger side. This aperture also carries the fresh air input to the cab. Over the years this well had become full of dirt and no doubt this contributed to the leak. I cleaned out the area once the grilles had been removed and fitted an extension to the drain tube. Note that rough handling of the drain tube will unwedge it from the bottom of the well which will result in rainwater draining directly onto the gearbox.

The first job I tackled after the gearbox was back in place was to level the engine/gearbox and remove the jacks. There were a few boxes of parts to reassemble and I set to work fishing out the mounts for the gearbox. During disassembly I now recall the fact that, of the four fixings for that (now repainted) cast aluminium part shown right, two nuts came off (17mm) but two nuts drew out their studs. I'd forgotten this and assumed a couple of bolts had been fitted. I found it extremely tricky matching up the holes so the very long bolt could be inserted. It meant arranging the pair of fittings precisely, with less than 0.5mm discrepancy, before the bolt passed through both. This was done by adjusting two jacks and levering with a large screwdriver. I then noticed the bolts stopped screwing in by a couple of mm and not tightening.

I looked at the drawings in the Ducato manual and then remembered the studs.

Of course, if studs are used, it's only necessary to line up the pair of fixtures in one (horizontal) dimension because the left part can be lifted or lowered into place to line up the holes for the long bolt.

Below, the correct studs are now fitted with their 17mm nuts.

Note also that single stud (not a T20 bolt) in the main casting below.

Note the (temporarily) extended drain tube.

This picture is from the Fiat manual for the "new" Ducato. Peviously, and possibly in error the pin labelled "15" isn't shown in the ELearn drawings, instead a bolt is shown.

Refitting the mounts above was puzzling. Initially I thought I'd mislaid one of four securing bolts for the lower mounting bracket but then spotted, from the pictures I'd taken, that two bolts and two posts are used. One post (part 15 = 9639-29-0180 replaced by 9684-04-5780) is used for mounting the bracket for anchoring the gearshift cables (shown in the right-hand picure). The posts are similar but different. The second (part 16 = 9684-04-5380) has a larger centre shoulder than the first. These posts are presumably designed to make it easier to align the mounting bracketry.

Next, the mount for the gearbox to chassis (below).

Now, here's a puzzle. During initial disassembly, the mounting plate is in position above left with both studs located. Then you can see the nearest stud has been unscrewed and the other left where it is. The studs are 14mm diameter and the holes are 14.25mm diameter. Stud 16 has a centre bush of 14mm and stud 15 a centre bush of 18mm. That means the two studs were reversed. The proof is that the nearest stud (part 15 with the 18mm fat centre bush) could not have been extracted through the 14.25mm hole, but it has so must have been part 16 not 15. The explanation is the cambelt was changed last year and the mechanic must have reversed the two pins.

Why are the two studs different? They're both the same overall length of 90.5mm and have identical M14 threads. In fact all the other variations of the Ducato use three bolts and only one stud. That single stud is used for aligning the mounts as the pair are in the "new" Ducato..

As I'd already fitted the gearbox to the engine I didn't want to remove the mount so I could fit the second stud (that's the one that is used to line up the mount to the gearbox). That stud cannot be inserted through the mount bolt hole so I ground away the fat part until the diameter was just 14.25mm. It wasn't easy with basic tools but I managed and it fitted perfectly. I used a 5/8 inch socket (which fits the top of the stud) mounted to my impact driver to fit it. Below is a picture showing the mounting arrangements with the studs secured by M14 nuts.

Now, fitting the lower mounting bracket.

This Elearn picture accuracy is pretty poor but at least it gives you some guidance. The bolts (1) shown are M14 x 100mm and (2) is M14 x 80mm. The two holding the triangular fitting to the gearbox casing are M12 x 60mm.

This view is looking towards the gearbox with the "Bracket" wedged under the chassis. This somehow mates up with these two shock mounts on the right. See drawing above.

One hole for the larger shock mount can just be seen above.

The centre bush of the smaller shock mount fits between these prongs. One side of which straddles the (silver) gearbox flange and the other, as you can see here, will be positioned by some levering. This proved to be straightforward, as once the jacks were removed, the engine and gearbox could be moved easily to fit the triangular mount.

This was followed by fitting the bracket, which bolts to the upper part of the gearbox, for holding the twin gearshift cables shown below.

Thankfully the gearshift lever very smoothly selected all the gears. Previously, before the gearbox broke,. it had been pretty heavy.

Above you'll note the temporary drain tube extension. This will be sorted out later and will include anchoring it into the well behind the grille.

This picture shows the half-shaft refitted (a very difficult job as it only just wedges into place). The hub nut is screwed up and awaits tightening to around 350Nm and then punched into the slot in the shaft.

The suspension bolts were tightened to 150Nm. The hex-slot caliper bolts (not visible here) were tightened to 210Nm. The track rod end was 80Nm and the anti-roll bar (undone to allow the half shaft to be refitted) was 56Nm.

Copper grease which you can see in both these pictures was used to prevent rusting.

Several smallish tasks were then undertaken. Because of limited space I tackled the fuel connection first. This was made with a section of rubber fuel pipe with an internal bore of 6mm to fit the nylon tubes. The outer diameter of the rubber tubing was about 11mm and ideal for clamping with standard hose clips (these had been supplied with the tubing).

See picture opposite... As the black nylon tubing is relatively stiff it would fit in the existing clamps so I made a wooden block to hold the new 8mm tube to the adjacent 10mm tube. This was made by first drilling 8mm and 10mm holes in the wooden block. Then a third (6mm) hole at right angles between them. Then the block was split to accommodate the pair of tubes and screwed together. This prevented undue strain on the repaired fitting.

The original quick release fitting was cut off and the rubber tube clamped to the 8mm nylon tube from the fuel filter.

It's now worth mentioning filling the gearbox with oil. I bought three litre bottles of Granville MTF FS 75W85 for £40 and used exactly 2.7 litres which is Fiat's revised amount. Why "revised" you might ask ? Well after regular gearbox problems costing Fiat's customers hundreds of thousands of pounds of expensive repairs they decided the original specified amont of oil was too low. Oops!!

There's another problem worth (re)mentioning here as well. Because of the inept design of the method of getting rid of rainwater draining off the vehicle water gathered on the top of the gearbox. In some cases (not mine) this water can find its way under the gearbox oil filler plastic cap which is merely pushed over the hole (see picture on left). Any ingress of water contaminates the gearbox oil....

I found an ideal method of filling the gearbox.

I found that the length of fuel pipe for repairing the damaged pipework fitted snugly into the gearbox filler hole. I threaded the tubing to the bonnet support and used a small filter funnel as shown opposite.

By allowing a small steady trickle of oil it took about ten minutes to add my 2.7 litres of oil.

The next job was to refit the air cleaner casing. More inept design. I'd imagined that this was going to be easy but it wasn't. The thing mounts on the three rubber shock mounts (fitted earlier) but was an interference fit and had to be jammed into the space between the fuse box and the bodywork.

Next was fitting the new air cleaner cartridge. This was also a case of jamming it into position and wiggling the base of the cartridge into position around the air outlet.

The top part of the casing looked too small compared with the amount of cartridge sticking out but it did fit (not forgetting the rubber sealing ring). It's secured with four self-tapping scews, two of which are virtually impossible to reach. In the end I had to use shorter screws and a stubby screwdriver for the rear two.

Now another problem but which may be due to ageing of the parts making them a lot less flexible than they were originally.

I fitted the air inlet tube from the engine after a lot of persuading before it jammed into place (there's a locating notch which needs to be correctly lined up).

However, the fresh air inlet pipe shown here was impossible to fit before first removing the plastic fitting bolted to the bodywork. Of course, after 20 years, the ends of those M8 bolts were badly rusted and needed WD40 to help persuade out.

One removed I was able to fit the plastic fitting to the tube and reclamp it. The other end that fits to the air cleaner needed copper grease to get it to push into place.

Below, everything apart from the engine cover looking good.

I tried the gear lever and all the gears selected smoothly. I connected the battery, and in neutral, turned the key to run the fuel pump. There was a little spluttering, but then turning the key further, the engine stuttered a little but started and ran perfectly.

I secured the axle nuts to a decent torque, fitted the front wheels, and removed three axle stands and the jack. The van is now back on its wheels for the first time in a month.

What I failed to mention was that as I was about to start the engine I'd pressed the clutch pedal and it sank immediately to the floor. Ooops.. that shouldn't have happened.. I'll fix that later.

Around the clutch operating cylinder I noticed evidence of brake fluid and when I looked at a previous picture I'd taken when reassembling the fuel pipes I saw that a clip was protruding where it shouldn't have been (see below). The purpose of that clip is to lock the incoming fluid pipe into position. The fluid pressure from the pedal had withdrawn the pipe from the cylinder by around half an inch and simultaneously opened the bleed valve. Fluid had shot out the bleed nipple and then allowing the clutch pedal to rise had drawn air into the cylinder.

Fortunately this was easily rectified as bleeding the Ducato clutch takes only a minute or so. I pulled back the pipe and my wife pressed down on the clutch pedal. Air and some fluid came out. Once the pedal had been floored I pushed back the pipe and held it in position. Then once pedal was back up I pulled out the pipe and she again pressed the pedal. This time a stream of brake fluid emerged, I pushed back the tube and pressed back the clip. The clutch is now fully operational.

pending