Clutch slips when hot

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naff_monk
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Clutch slips when hot

Post by naff_monk »

Hi All

Tried the usual googling but can't find the answer to this one so hoping someone can help.

Some background:

Clutch slips slightly when hot (usually when the turbo kicks in in 3rd-5th). It's had a new kit approx 600 miles ago when I had a second hand box put in, problem first appeared after a few hundred miles at high speed on the motorway but I can get it to do it after 10 mins at 60mph now.

My expectation was it was likely to either be adjustment of the hydraulics or contaminated clutch, hoping the former. I've never dropped a gearbox before but decided to have a crack at it as my local garriage seemed reluctant and I'm not too keen on paying piles of money on labour for a non working drivetrain and I wanted to rule out gearbox leakage. I got as far as removing the slave cylinder before I noticed an inspection hole in the bell housing, why had I not noticed that before! Decided to re-assemble, get it hot again and shove some clutch cleaner down there to see if that made any difference before going to the trouble of dismantling anything.

Now, to my question. On re-installing the slave cylinder, I noticed that the rod is protruding further than the start of the clutch lever swing. I could get it on by tightening the bolts but that will deffo disengage the clutch a little leaving me with negative free play which leads me to think that this may have been my problem all along? I'm thinking if I bolt the slave cylinder back down then open the filler cap under the dash, the fluid should rise as the diaphragm spring returns the lever back to it's natural position and with any luck I should be sorted. Does that sound right or have I missed something here?

Cheers
Laurence
1988 Leisuredrive high top rust bucket
1.9TD ABL (JX pump & turbo)
5 speed 3h

silverbullet
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Re: Clutch slips when hot

Post by silverbullet »

The slave cylinder has a light spring inside, to keep the pushrod seated and prevent the release fork etc chattering when the clutch is engaged.
Its usual to have to shove the pushrod up into the slave just to get the bolts in and tightened.

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naff_monk
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Re: Clutch slips when hot

Post by naff_monk »

Ah right, that explains that then. Back to the clutch cleaner idea then.

Any suggestions for things to look out for if/when I get the clutch apart would be helpful also :)

L


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1988 Leisuredrive high top rust bucket
1.9TD ABL (JX pump & turbo)
5 speed 3h

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Aidan
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Re: Clutch slips when hot

Post by Aidan »

215mm clutch is marginal with higher output engines with a TDi maybe 20k miles life rather than the 60k miles with the original 1.6 engine
which brand clutch was fitted, I have heard from reputable trader the supposed upgraded ones like Black Diamond have proved to be anything but, just a con.
I would always use a Sachs clutch if I could, the release bearing is the best and they tend to be proper new manufacture rather than refurbished or made in 2nd/3rd world countries with lower quality components
The inspection cover for the diesel timing mark hole is very important, mostly they are missing due to slack ignorant mechanics, allowing fuel oil, engine oil, coolant (depending on which your engine leaks - I have never seen a diesel engine that didn't leak one, mostly they seem to leak all three :lol: ) and road dirt and water to contaminate the clutch and corrode the release fork and especially the brass bush

naff_monk
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Re: Clutch slips when hot

Post by naff_monk »

Clutch was a sachs for a JX from ECP. Probably worth mentioning that the engine is an ABL but had a JX pump and turbo so is a JX in all but name. Interesting to hear about the black diamond clutches, at some point I'd like to swap to an AAZ/GTD pump and up the boost so was probably going to fit one. Might not bother now!

So I put everything back together and took it out for a spin. I've obviously managed to mess up re-installing the slave cylinder/linkage because the bite point is much sooner on the pedal now and the gear shift is crap. I'll worry about that later though because I got it hot and slipping again, pulled over and got my head in there. There was a wisp of smoke coming out of the hole, it smelt more burnt oil (slightly fishy) as opposed to burned rubber, sprayed liberal amounts of clutch cleaner down there and tried again, still slipping. Got home and got my finger in there, came out dirty/oily, flywheel temperature was comparable to the oil filter so I'm assuming clutch contamination now.

Looks like drop the box time, wish me luck :ok
1988 Leisuredrive high top rust bucket
1.9TD ABL (JX pump & turbo)
5 speed 3h

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Aidan
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Re: Clutch slips when hot

Post by Aidan »

have you mixed up parts from two different slave cylinders by any chance, the pushrods on the FAG style and ATE style are different lengths

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Re: Clutch slips when hot

Post by silverbullet »

Crankshaft seal needs replacing?

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Re: Clutch slips when hot

Post by dave friday »

Fishy smell? My guess is Gear box oil ( was the spigot bearing fitted?)
Good luck.
I dont think, so I'm not[do I exist?]
1992 1600td [ jx ] syncro panel van[leisuredrive camper ]

naff_monk
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Re: Clutch slips when hot

Post by naff_monk »

Hi All

Just thought I'd wrap this one up. Dropped the box and found the whole bellhousing spattered with a liberal coating of transmition fluid:

Image

I couldn't be bothered to remove the flywheel but had my finger in there and there was a needle bearing that seemed to be in good order, there wasn't excessive play in the drive shaft either so assumed the seal had been compromised.

A few odd things to note here. Drained 4.5l of oil from the thing, now I was under the impression that this is approx 1l over filled? If this is the case, I guess this could produce higher pressure and contribute to the seal failing? Either way, I removed the bellhousing to check for this oil thrower I hear mention of, all present and correct although there was no gasket on there, just some black sealant of some kind, I'm certainly no expert but surely this is unnecessary corner cutting??

Anyway. New input shaft seal installed (levered off with an allen key, big socket to drive it on), removed old sealant, degreased the bellhousing and replaced with the proper gasket, another new clutch kit and box back on the van and promptly drove it 500 miles through the Scottish mountains so I recon, touch wood, we're done! Happy bloody days.

:ok

Image

Cheers for the help, really couldn't have done it without the the knowledge shared on this site and general words of encouragement.
1988 Leisuredrive high top rust bucket
1.9TD ABL (JX pump & turbo)
5 speed 3h

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