Bad throwout / pilot bearing?

[SlowGoing]

Hi Samba,

I'm wondering if anyone might be able to help me diagnose a transmission problem I'm having in my Westy. I have an '82 (formerly diesel) Westy with a 1.8L I4 hooked up to a DM code transaxle (off a tin top diesel).

The transmission was recently rebuilt by a reputable rebuilder; the clutch is also relatively new (~5000 miles). I also recently replaced the CMC and had a hydraulic fluid flush.

Here's the problem: When the clutch is engaged (i.e. pedal not depressed), I hear a whirring / chattering noise coming from the transaxle. The noise goes away when the clutch pedal is depressed. This has been going on for some time, but recently I've noticed that my clutch engagement has been getting worse and worse. I used to be able to get the van started easily with very little gas, but now the clutch feels a lot more "touchy," and I seem to have to rev it up over 2000 rpm to keep it from stalling. The "feel" of the clutch pedal has also been a little strange: I can feel a very faint vibration / pulsation through the pedal, and it feels a little more rubbery when I depress it, whereas it used to engage / disengage very smoothly.

I was thinking this could be a bad throwout bearing, but I've heard that bad throwout bearings tend to make noise under the opposite conditions (i.e. noise when clutch pedal is depressed). So maybe it's a bad pilot bearing? Any thoughts?

Thanks for any and all help

[Vanagon Nut]

The clutch is new but did they (or you) replace the pilot bearing?

Was the cross shaft in clutch housing replaced?
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[SlowGoing]

I believe — but am not absolutely certain — that the pilot and throwout bearing were replaced when the clutch was changed. I could be wrong though, and I can't find the documentation I'd need to be certain. I am sure the cross shaft was not replaced, though.

I also saw this thread about the oil slinger: https://www.thesamba.com/vw/forum/viewtopic.php?t=342440

and wonder if maybe this could be related to what I'm experiencing (if there's a pilot bearing failure, perhaps due to felt pad not being properly reinstalled).

I guess the only way to be certain is to drop the transmission again

[Vanagon Nut]

[jberger]

Is your idle tick-over smooth? Inline 4's can have a bit of vibration at idle which can contribute to noise from the main shaft bearing in the transaxle. I have experienced main shaft bearing noise from the same engine with different camshaft profiles affecting idle pulses.

[Gnarlodious]

Everything you described matches the symptoms if someone put a gasser engine onto a diesel trans using the diesel input shaft which is too short. Because it is work to change the input shaft to the gasser one, the ignorant mechanic just bolts on the gasser bellhousing without measuring the shaft. It is probably wobbling around in there and made a big old mess of the oil slinger and bellhousing. Advised to stop driving immediately. In addition, you are probably wrecking your 1ˢᵀ gear synchro since the clutch has been wobbling and dragging. Expect internal damage.

https://www.thesamba.com/vw/forum/viewtopic.php?t=603453

[SlowGoing]

I believe my swap has the diesel input shaft, but I'm also using the diesel bellhousing -- If I recall correctly, using an inline 4 gas engine with the diesel bellhousing and trans requires using the shorter input shaft, no? Or do you only use the shorter input shaft if you're using a gas trans with a diesel bellhousing?

http://volksweb.relitech.com/vanagon2.htm

[Gnarlodious]

The gas engine trans on a diesel would not even fit on because the shaft is too long, it would be obvious something is wrong. The other way around is the problem, you bolt the diesel bellhousing onto the gas engine and it fits, never knowing the shaft is not even inside the pilot bearing. And it runs fine, at first, so you think the job is done. But a ways down the road that shaft starts wobbling, because all that is holding it straight is the oil slinger bushing, which gradually gets hammered loose from the wobbling.

That said, I don't know what the 1.8L engine uses for bellhousing and input shaft. It sounds like you are stuck with taking the trans off and having a look see.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[Vanagon Nut]

[SlowGoing]

OK, so today I drained the gear oil and dropped the transmission. When I drained the gear oil, I found only a very small amount of shavings on the magnet -- the oil was otherwise clean. But after dropping the transaxle I can confirm that at least the input shaft seal is bad: gear oil was seeping into the bellhousing, although there didn't appear to be a lot.

I also spun the throwout bearing and pilot bearing and both seemed fine (smooth rotation, no play or noise). I then spun the transmission by hand and it too spun smoothly without any odd noises. That's when I noticed that my clutch disk was rattling! When I shake the clutch disc it sounds like maraca. Possibly one of the springs in the clutch is loose, or there might be something internal in the disc mechanisms that's spinning around — it's hard to say. After a bit of googling it looks like a rattling clutch disc would cause the same symptoms that I was experiencing.

So right now the plan is to replace the clutch disc and the input shaft seal. For the life of me I can't remember, if I have an 8v Jetta engine hooked up to a diesel transmission, can I use a jetta clutch kit?

[Vanagon Nut]

[Gnarlodious]

My clutch was totally worn out after 200k miles. I mean the springs lost their springiness even though everything looked good. So its a good idea to replace your pressure plate routinely.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[SlowGoing]

Thank you, Neil and Gnarlodius, for all of the very helpful input and advice. It is deeply appreciated. I'll report back after all the parts are replaced and things are re-assembled. Now, where to find a diesel vanagon clutch on the 4th of July...