Technical Any advice on fixing this gearbox leak?

[joecross98]

I've got a slow, steady leak from the gearbox in my 2002 Fiat Ducato 2.8 JTD. I'm fully prepared to take it to a shop to get fixed, but I'd like to have some idea what the likely problem is before I do so.

We bought the RV about 2 years ago and have put about 15K kms on it with zero problems. From the paperwork I got with it, it was very well taken care of. The only issues I've noticed while driving are:

• It lurches a tiny bit in 3rd gear. Feels a little like a clutch problem.
• It can be hard to get into reverse sometimes, but it always finds its way there eventually.
• At very low RPMs, there is a grinding sound that I don't love. I'm new to diesels, though, so it may be normal.
• The speedomoter recently stopped working - probably not related.
• Now this slow leak. It seems to be coming from two places. The seal on the left seems like a natural place for a leak, so I'm more worried about the gash on the right that looks like we may have hit something and cracked the case.

Any feedback or tips on further diagnosing the issue would be appreciated. I just hate going to a repair shop blind - it's an invitation to get robbed.

 

[rolandbrindley]

That leak is from the clutch housing and not I think from the gearbox. Have you checked the oil level in the gearbox to see it it is falling or maintains its level? There should be an oil dipstick so this is an easy check apart from the crawling under part.

Oil coming out of the clutch housing will be one of two colours. Black is engine oil, all diesels blacken their engine oil as soon as it's put in. This oil will be getting into the clutch housing by passing the rear crankshaft oil seal, then being flung out by the rotating flywheel and flooding the walls of the housing. Some will be getting onto the clutch linings and causing the gear selection and clutch trouble you are having.

To replace this seal is a major operation. It may be possible to do it with the gearbox out so the seal and seal housing can be removed, but I suggest that engine out is the preferred option. I know about gearbox removal, (see my guide), give me the engine out, it's no worse.

In any case expect to fit a new clutch as it will be seriously contaminated.

The other small place where you point out a leak looks like the clutch withdrawal arm spindle, just another place where clutch housing oil can drip out onto the floor.

If the oil leak is clean oil then it's gear oil, and to get into the clutch housing means the gearbox has been overfilled. Again check the oil level in the gearbox before doing anything else.

If you are losing engine oil via the crankshaft oil seal you will be noticing this when you check your engine oil. By the way the 1929 TD diesel is notorious for using oil in the normal course of events. Mine does anyway and is in decent order.

 

[wavehead]

Okay, so yes I had a leak just like that...

Now don't panic about what i am going to say...
Yes I think he may be right it is not the gearbox, at least it wasn't in my case. I had the leak for years, squeezed the van through MOTs with it. It was the main engine bearing leaking through to the clutch side and started when the garage put new synthetic (thinner oil) in my 1996 Fiat Ducato. I had it changed at great expense and the clutch as its easy to do once the gearbox comes off, only for it to still leak a bit still. Anyway the upshot was its a big expensive job so I ignored it as it was an old van ( yes I know thats a bad boy thing). Not sure about your other problems...they could be clutch/gearbox probs either way it all gets very expensive...

 

[joecross98]

Thanks for the feedback wavehead and rolandbrindley. Not happy about major work, but at least I know what I'm dealing with now.

The oil is definitely black. Sadly, my model does not seem to have a gearbox dipstick, just the square drain plug and filler cap under the air filter. So other than fully draining and measuring, I don't know of a way to check the gearbox oil level. Any advice on whether I should change the gearbox oil just to make sure there's enough in there?

I keep a close eye on the engine oil and it drops very slowly but surely. I had chalked it up to diesel things and top it up every now and then. But it's not so bad that I ever worried about it.

I'll likely sit tight for now and see if anything gets worse. Frankly, it drives strong and has been super reliable. Once I save up some money, though, I'd like to do her the honor of getting the problem fixed. Assuming I do the full treatment and have someone replace the crankshaft oil seal and clutch (I'm not equipped to do it myself) - any idea how much money I'm in for? Is this a 1000 euro fix or 10x that??

 

[rolandbrindley]

If it were my van I would expect the worst scenario, and any repair shop worth considering will tell you to expect a bill for gearbox out and refit, new crank oil seal and new clutch. The clutch repair could mean a new or refaced flywheel if the mileage is over say 75000km. They will also fit a new clutch release bearing and anything else they find along the way such as refrigerant and water hose clips.

That may not be all, sadly. The crank oil seal may have begin to leak because the crank main bearings are getting sloppy, and at least a set of new main shells may be required to fix this, needing oil pan removal and perhaps more, as I only know the 1929TD engine details. Then there is the oil pump to check . . . . . and so on.

If the worst case arrives then expect a bill up to E 2000 or so, and in Spain it could easily exceed that. Many small shops would likely refuse the work as there are lots of chances to take and get right. Many back street repairers draw the line at major jobs like this.

I suggest you look up the sides of the gearbox casing for a level plug which when removed will enable you to poke inside and find the level, and top up if necessary.

Your comments about dodgy reverse selection may be down to simple cable or selector shaft adjustment in the gear lever mechanism. Is it floor or column change? The LHD column change mechanism is quite simple compared to the floor change ones but they all need to be well lubricated with duck oil.

Your comment about a grinding at low speeds I can' t think sensibly about but my 1929TD diesel is a smooth quiet unit (for a diesel) and makes no such noises. More information is required.

 

[corcai]

Gear oil smells like cats pee easily distinguished with a finger and nose. Looks like crank shaft seal which is a not too much extra work if you are doing the clutch. If you are using 5w40 go back to 10w40 or even 15w40 if you are not running in sub -10C and don't fill to the max mark. You may find it doesnt leak at all if you only fill to 1/3 or half mark on the dipstick. Theres still 5-5.5 liters of oil in the engine it doesnt present an issue unless you are burning oil which is rare on these engines.

As Roland says reverse could just be adjustment but also the pivot on the gearbox probably needs dismantling, cleaning and greasing

 

[wavehead]

It cost me about £850 for clutch and rear crankseal in 2014 at Chelston Motors. So I would say £1000 now.

 

[joecross98]

This is great advice all, thanks a bunch. I had braced myself for more than 2000 euro, so in a deranged way, this is good news.

We've got a Fiat repair shop nearby as well as as a caravan shop. I think I'll take it to both and see if their stories and estimates line up (assuming they'll take the work). In the meantime, I'll check the gearbox oil level and research how to grease the dash shifter to help reverse. I've got 10L of 5W40 Petronas that I just got for engine oil change, but maybe I'll grab some 15W since Andorra is the coldest we're likely to get any time soon. Thanks again.