Technical Gearbox Issue

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Technical Gearbox Issue

bri52

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Just suffered what I have since found out a very common fault on Ducato 1998 gearbox. 5th Gear fails to engage. According to internet this gear is a ''bolt on'' to a 4 speed box and can suffer from lack of lubrication over time. Well documented by Gary Box (Motorhome Vagabond) and although can be fixed 'in situ' if you can find a gearbox specialist, not a garage, to do the work. In any event a very expensive project. Anyone had this done?
I live in Shropshire and looking for hopefully a recommended repairer. Fiat Ducato 2.5tdi 1998 Motorhome.
 
I cannot help with a recommended repairer, but for the future I would like to relpeat some advice.

The fifth gear is indeed an addition, and relies on splash lubrication from the main part of the box via a trough.
This method of lubrication is OK for vehicles in daily use, but is not so good on motorhomes, which often have extended stationary periods.

The advice that I try to follow is not to use fifth gear for the first milr or two, particularly after several days layup when the oil will have drained into the main part of the box.
 
I cannot help with a recommended repairer, but for the future I would like to relpeat some advice.

The fifth gear is indeed an addition, and relies on splash lubrication from the main part of the box via a trough.
This method of lubrication is OK for vehicles in daily use, but is not so good on motorhomes, which often have extended stationary periods.

The advice that I try to follow is not to use fifth gear for the first milr or two, particularly after several days layup when the oil will have drained into the main part of the box.
Thanks for the reply. I have read responses elsewhere whereby it is recommended to 'slightly' over fill the gearbox and even add an additive such as Molyslip.
There is even a YouTube on the subject (found today) which suggests it can often be the Slip Ring behing the 5th gear being worn or damaged, however we will start with basics and fully inspect the gear lever linkages before tackling the gearbox. My Brother in Law is a fully qualified mechanic and has offered to tackle the job so fingers crossed especially for my bank manager.
 
Thanks for the reply. I have read responses elsewhere whereby it is recommended to 'slightly' over fill the gearbox and even add an additive such as Molyslip.
There is even a YouTube on the subject (found today) which suggests it can often be the Slip Ring behing the 5th gear being worn or damaged, however we will start with basics and fully inspect the gear lever linkages before tackling the gearbox. My Brother in Law is a fully qualified mechanic and has offered to tackle the job so fingers crossed especially for my bank manager.
Once fixed, be aware that certain oils for gears have additives that will attack the (bronze, I think) parts of the 'box. I suggest following Communicators advice about avoiding top gear for a few miles after standing, and sticking to Fiat recommended oil. Unless a 'box specialist who has done lots of these specific repairs, and has the experience to match advises otherwise. There is much discussion on here. The overfill is an accepted wisdom too. You could have a word with Dave Newell in Telford- he does a lots of motorhome stuff, he did my cambelt on my A class for dead right money. He knows these Fiats pretty darn well, but not sure if he 'gets that oily', but it won't hurt and he may know someone if he cant.
 
Thanks for the input.
Have owned the motorhome for 10 years now without a single issue, we changed the gearbox oil only last year part of a major service. Will look up Dave Newell on Google for reference purposes but we are planning to tackle repair within a week. MH is 24yrs old with 78k on the clock but in excellent condition throughout for it's age and rarely has issues even at MOT time thanks to my brother in law.
 
Once fixed, be aware that certain oils for gears have additives that will attack the (bronze, I think) parts of the 'box. I suggest following Communicators advice about avoiding top gear for a few miles after standing, and sticking to Fiat recommended oil. Unless a 'box specialist who has done lots of these specific repairs, and has the experience to match advises otherwise. There is much discussion on here. The overfill is an accepted wisdom too. You could have a word with Dave Newell in Telford- he does a lots of motorhome stuff, he did my cambelt on my A class for dead right money. He knows these Fiats pretty darn well, but not sure if he 'gets that oily', but it won't hurt and he may know someone if he cant.
I recall reading that Fiat used to recommend GL5 oil for the gearbox, but now only recommend GL4.

It is the GL5 specification that has a higher level of additives, which attack the bronze components. GL5 oils are good for hypoid differentials, where to prop shaft is offset from the half shafts, which results in a partially sliding motion on the gear faces. However this does not generally apply to front wheel drive vehicles, where a GL4 oil may be a better choice. A web search will reveal many articles on GL4 versus GL5.
 
According to Peter Russex Manual the gearbox requires 1.85 litres of oil but merely states Total Gearbox Oil but having researched online for GL4 I will choose Comma brand. The question is to ''slightly overfill'' the box after repair but what amount to actually use. Logic may suggest 2.25L max ?
It's only come to our notice since this problem but our driveway where MH is parked has a slight but obvious slope towards the house (to the left) when MH parked therefore oil would logically seep into the the 5th gear while standing. Might explain why no previous problems but why now? The YouTube video actually found worn/damaged Syncro Ring as the problem which are ridiculously priced at £52.50 on ebay. The OEM gears are £450 on average for 2.
Fingers & Toes tightly crossed.
 
According to Peter Russex Manual the gearbox requires 1.85 litres of oil but merely states Total Gearbox Oil but having researched online for GL4 I will choose Comma brand. The question is to ''slightly overfill'' the box after repair but what amount to actually use. Logic may suggest 2.25L max ?
It's only come to our notice since this problem but our driveway where MH is parked has a slight but obvious slope towards the house (to the left) when MH parked therefore oil would logically seep into the the 5th gear while standing. Might explain why no previous problems but why now? The YouTube video actually found worn/damaged Syncro Ring as the problem which are ridiculously priced at £52.50 on ebay. The OEM gears are £450 on average for 2.
Fingers & Toes tightly crossed.
I think the overfill amount is only 200ml which is not much. The tilt on your drive may indeed have helped, as 200ml in the volume of the 'box won't have a spectacular effect on the oil level I would think. Let us know how the repair goes please- it crops up on here quite often and your info may help others later on. Best of luck!
 
Will do. The main factor at the moment is the weather but when a dryish spell is forecast we will get underway,
 
I just put 2.75ltr of fully synthetic GL5 yellow metal safe oil into our Ducato 2000 2.8idtd five speed. Amount is listed in the manual available on this site, thanks to Ben:


The fill procedure via the reversing light switch hole was a pain. If your gear is gone, parts are available from Warrington Transmission Centre for about £180. Getting the gearbox end cover off to inspect is reasonably easy. I was lucky and didn’t need to get the gears off, but there are a couple of good YouTube and forum sources on the fix. I’ll try and refind the links and post them.
 
Many short clips, but still useful:



From what I’ve seen, the fifth gear selector can be held in place by either a pin through it and the shaft, or a clamp nut. Mine has has clamp nut but I didn’t need to undo it as a visual inspection of the synchro ring in place looked good.

There are (were?) different ratios available for the fifth gear, mine had the numbers marked on the gears.

Useful guide on oil change for a box without a fill point/dipstick:

 
Update on my gearbox problem.
We removed the gear assembly in situ to fully inspect and noticed there are 3 sprung loaded ball bearings surrounded by the 5th gear syncro hub sleeve and 1 ball bearing was completely missing, no sign of it antwhere. The hub sleeve itself did show signs of wear but the missing ball almost certainly the problem.
There did appear to be plenty of gear oil lubrication over the gears and inside the end cover.
Will source parts locally from specialist if possible and re-assemble.
 
Every day a school day it seems.
Took the whole 5th gear set up to a gearbox specialist near me who advised too badly damaged/worn and to search internet for replacement.
Found ASAP Gearbox on ebay who supplied the lot brand new the next day (today) unfortunately £415. The old gears did at least survive 79k miles and for me 11 years trouble free touring so peace of mind for our next trip to Spain. Should be back on the road next 24hrs.
 
Just suffered what I have since found out a very common fault on Ducato 1998 gearbox. 5th Gear fails to engage. According to internet this gear is a ''bolt on'' to a 4 speed box and can suffer from lack of lubrication over time. Well documented by Gary Box (Motorhome Vagabond) and although can be fixed 'in situ' if you can find a gearbox specialist, not a garage, to do the work. In any event a very expensive project. Anyone had this done?
I live in Shropshire and looking for hopefully a recommended repairer. Fiat Ducato 2.5tdi 1998 Motorhome.
Had the same issue several years ago. The sealed gearbox was cracked open, they then determined that the min level of oil was not enough and FIAT paid for the repairs. All they did was put more oil in, resealed and no probs since. Apparently a well known issue by FIAT.
 
Every day a school day it seems.
Took the whole 5th gear set up to a gearbox specialist near me who advised too badly damaged/worn and to search internet for replacement.
Found ASAP Gearbox on ebay who supplied the lot brand new the next day (today) unfortunately £415. The old gears did at least survive 79k miles and for me 11 years trouble free touring so peace of mind for our next trip to Spain. Should be back on the road next 24hrs.
79k miles in a 3 ton plus van is pretty good going ,,the base vans almost never run around with that sort of weight
 
Thread revival....

Hi all,

I've got a 99 Ducato Motorhome and seem to have a poss syncro issue on 3rd gear as it crunches moving upto and down to 3rd. Are parts avaiable? I was under the impression that there was nothing made for them anymore, but this therad seems to suggest different.

Cheers all :)
 
Just suffered what I have since found out a very common fault on Ducato 1998 gearbox. 5th Gear fails to engage. According to internet this gear is a ''bolt on'' to a 4 speed box and can suffer from lack of lubrication over time. Well documented by Gary Box (Motorhome Vagabond) and although can be fixed 'in situ' if you can find a gearbox specialist, not a garage, to do the work. In any event a very expensive project. Anyone had this done?
I live in Shropshire and looking for hopefully a recommended repairer. Fiat Ducato 2.5tdi 1998 Motorhome.


I've just replaced the complete 5th gear plus syncro (1999 2.8 ducato 164, 000 kms)
£399.24
Screenshot_20230124_121114_com.google.android.youtube_edit_467289804758904.jpg

Done in situ in 2hrs including oil refill.
In my case the captivated nut had worked loose holding syncro (center of large cog).
2 x teeth broke and found in casing.

Method was Jack up nsf wheel to gain access then jack stands.
Drain g. Box completely.
Carefully remove 5th gear casing to expose gears.
Flatten out nut retaining ring and remove with flat nut.
Pay attention on how gear is situated and carefully remove off spline, being careful not to let any of the 3 ball bearings to drop from the inner face of the syncro hub.
Familiarise yourself with new parts and how they go back in.
Clean up, lubricate shaft splines and carefully reassemble.
When it came to tightening hub/gear nuts I searched high an low for torque settings without avail.
So tightened to first grunt 😁 and made sure locking tabs were good in place. Managed to get 3 to line up.
IMG_20230312_153712_edit_469338815983592.jpg


1500 kms later all good.
Refilled g.Box via reverse switch 2.7L .EP 75W-80. GL4
 
Last edited:
Thread revival....

Hi all,

I've got a 99 Ducato Motorhome and seem to have a poss syncro issue on 3rd gear as it crunches moving upto and down to 3rd. Are parts avaiable? I was under the impression that there was nothing made for them anymore, but this therad seems to suggest different.

Cheers all :)


See my privious post the recited pic they advertise on the fleabay site but I rang them very helpful and very much cheaper.
They do the complete baring set but it's a box out job.
IMG_20230312_155528.jpg
 
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