smokey

How about the release bearing, the release bearing sleeve or "quill", the fork, and the fork needle bearings? Are these all ok? The release bearing and the sleeve should be replaced at the same time, becuase they wear together. Dumb question: is the clutch pedal free play set by the manual? Is the bell housing square? In one case I heard of, a 944 went through a number of clutches before the mechanic figured out that the problem was a bent bell housing caused by a collision. Just some thoughts.

PaulK

Thanks Smokey. I can only go by the dealer on the replacement of the release bearing, the release bearing sleeve or "quill", the fork, and the fork needle bearings - they checked out OK or were replaced in accordance with Porsche specs. Clutch pedal set to spec also by the dealer.

Legoland, my kid the computer whiz is going to rig up a video cam and TAKE MOVIES of the tranny and underside when this happens! Maybe that will help. Tonite, its shocks I guess. On the exhaust vibe issue, do you think that an aftermarket exhaust could possibly cause a heavy vibe only in one gear on a downshift? The vibe is so bad that something actually knocks against the body.

Raceit

That sounds exactly like mine PaulK....with the knocking/hitting sound. Does the *** end of your car sit lower then the front? Mine does.

My theroy on the bad shocks is that when you accelarate the force of the engine makes the car go forward and will naturally help plant the rear tires to the gound. Then the oppisite occours when you downshift. The tires will transfer the engery from your speed into the drive train. The reverse will cause the mass of the tires to sort of make them to start to roll around the axle. (If you get what I'm saying).

I'm no physics major, so explaining that in a way that works is probably pointless for me. But I feel that the lack of the functionality of the rear shocks will allow this energy tranfer to go unchecked and start one/or both rear tires to start to "hop".

Anyways that's what I've done with my spare time.

User 41221

Is it really a second gear only problem, or is that just the only speed range that its noticable in (ie: too slow in first, and too fast in third to notice it?) I can't imagine that its tranny related if you have swapped that out, so I would look at the cv's or rear wheel bearings.

If you want to call a guru, call Don Istook in Ft Worth, at 817-332-6547. I bet if you catch him on the phone and can describe what you've been through, he will have a very good idea where to direct you. I have personally never met anyone else who could come close to Don, as far as knowing a 944 inside and out.

Regards,

PaulK

Thanks Racit and sh944. I have some shocks in the garage and have ordered some complete axles. That leaves only a few parts left on the drivetrain to replace!!!!! Bearings might be the only area left after those are replaced. I assume they are a real bear to replace without a press. Its getting to the point where I do a 5 hour replacement job, and its actually sort of funny now when I drive it with my kid (20 yr old - great helper!) and it is not fixed!

qoncept944

Paul, don't hate me, but I say <i>let it break in</i>. The new (spring centered) clutch shudders when I downshift to 2nd gear. A month ago it did it a little in 3rd as well. It's gotten better over the last ~500 miles, and I imagine it'll continue for the next 500.

billybones

After sitting back and reading all of this. Does anyone know how the torque tube is actually attached to the bell ends? Are they welded? or mearly press fit? IT really sounds like the tube that is to transfer the torque maybe slipping and catching on the tube itself? And I believe the most torque is during the downshift to 2nd? Thus matched revs relieve some of the torque transfer. The fact that the tranny is bouncing off of the undercarriage is not right. Something is moving way to much. general question, Can you actually twist the tube so it is offset? what happens if you dent it or bend it? just a hair? I question how you spec out bearings that take a major removal process to even see. unless it was just run out at the shaft ends? It really sounds like a torque tube problem to me. Hope I am wrong.

Perry 951

I'll post this again.... better to check things before you spend a ton of money on stuff you may not neeed.

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Perry 951:
<strong>Is there a lot of back lash in the drive train? Put the *** end up in the air securly, put the car in gear, rotate a wheel back and forth in all gears and neutural. Make an approximation of how much the wheel can turn (in degrees) before it begins to turn the opposite wheeel. Take note of the difference between gears.

Since it only happens in 1 gear, I would say it has to be after the differential. (CV, bearings, loose hubs)</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">

PaulK

Thanks for the thoughts guys.

1) Breaking in: How many Rennlisters bought a 944 new? Did the factory clutch need break in? I never had a new 944 so I am not sure about the breaking in on a factory clutch. Since I now have a stock clutch should it need a breaking in period?

2) Torque Tube - there is another post series here that describes a similar mystery problem of shudder on downshifting, and that car had a replacement tube in it. Grrrr.

3) As I said, its axles next. I found a pair of rebuilt axles for $80 each locally. Actually, I have heard they are nothing more than VW vanagon axles anyway....no kidding. Porsche wants $169 each. The rebuilts have a 1 yr warranty anyway. While I am at that I have some aftermarket (KYB) cheap shocks to try out also.

4) If that makes no difference, I can't think of anything else in the drive train!

adrial

My mechanic told me the clutch is broken in the first few releases...

Tom Carson

is this more of an 'S2 problem'? aren't the S2 CV's different from the others? if you are going to replace the S2 CVs can/should you replace with something else?

Robert D

I have a small shudder at times. I've worked around it mostly.
Things I recommend checking:
A) Exhaust mounts - whats banging into the car

B) Torque tube shaft and bearing (when I did the clutch job, I had to tap the end of the shaft with a hammer to push the other end into the bearing in the center of the flywheel)...I wonder if this is why mine studders now.

C) Is there actually something hitting into the car? Or do you hear a tapping noise...could be something with the brakes on that. If something is hitting the car, there should be visible signs.

Good luck.
----------spring centered clutch, all new parts on clutch replacement, installed new wheel bearings 4k miles ago (3weeks ago)--------

pikey7

Is it ONLY happening in 2nd, or do you get it also to some degree in other gears? is there a chance that you/the shop got some oils or grease on the plate/flywheel??

Also, having never done a clutch job.... is there a chance of a leaking oil seal onto the plate?

Robert D

After 30k miles, the leaking main seal is not likely. I looked at mine at 160k miles and it looked perfectly fine. So if anyone wants the seal, I have it.

However, they are difficult to seat correctly. In which case if they replaced the 30k mile old seal incorrectly, this could have something to deal with the problem.

PaulK

Actually, I specifically asked the dealer who did the clutch about the seal. They checked it when the flywheel was off for resurfacing.

It only does this in 2nd. I have tried to duplicate in other gears for weeks but can't. That's why I swapped trannies!

As far as I know the CVs changed sometime in 87 or 88. The replacements are for the '91.

I have been thinking about when I first noticed this on the old, original clutch. It may have been after a giant pothole, actually. Strange i'll admit!