My '85 sat for a number of months (outside) over the winter.

When bringing it back on-line for this spring, it has developed a rotational 'whirring' noise that occurs only when the clutch pedal is depressed. It begins as soon as the lightest pressure is applied to the pedal and seems to be strictly related to the rotational speed of the engine. It becomes a bit more pronounced as I put more foot into the clutch... There is none of this noise apparent when clutch pedal is fully released.

Sorry - I'm probably missing something here on the site, but I've been searching and not finding the same set of symptoms in any of the pilot/TOB problem posts...

Looking to be able to have the appropriate parts on-hand once I undertake this job but not willing to sit on a $200 TOB for the duration if I really don't need one.

Thanks! Any experienced suggestions are genuinely appreciated!

 

Might as well changeout both.

 

Sounds like the throw-out bearing. The pilot bearing doesn't spin until the clutch is open.

Too bad as those are pricey. The pilot bearing is cheap.

 

it seems lke the TOB doesnt lke tohave any axial force on it. does it make the noise in gear or in neutral. (trying to narrow it down.) try it with the car runnign down the street at a slow speed in 1st. push the clutch in but keep the rpm the same, still hear the noise?


becuase you notice the noise when just pushing a little on the clutch,its probably the TOB, because the pilot bearing doesn move at all until you push the clutch all the way in and the engine running with the driveshaft stopped.

 

Gotcha, thanks! Mark: In gear and in neutral...

I've read about having a shop rebuild with a 6008 bearing... Can the center "tube" be re-used safely?

Also, if going that route, is there a specific "rating" for an appropriate 6008 bearing? (i.e. 6008 2RS, 6008 Z, ZZ, etc).

I'm on a pretty tight budget these days... :-( Don't wanna skimp too much though and hack it up. I know some pretty good local shops that could probably do this job for me.

 

Also, I'm guessing that the TOB isn't frozen, but is starting to fail. That is, I'm probably have not damaged the fingers on the PP yet. True? That would be a pretty horrific sound if I'm guessing correctly...

 

I have a good TOB if you want to buy it?
PM me an offer.

 

The fingers on the PP get damaged just from normal operation, and should be checked WYAIT.

TOB tend to just get noisy and don't freeze, unless left standing and unused for some time, or they've been noisy for a very long time and are so bad they seize.

 

I'm also in the TOB camp but I'm going to give you some advise you won't want to hear: If the TOB is worn it's because the entire system in there either a)hasn't been replaced in a long time or b)wasn't serviced completely. Like in, someone replaced the clutch disks but not the TOB or maybe some one or two other parts.

If the TOB is gone or going, the clutch disks are probably worn. That means you probably need the whole list of clutch replacement parts.

If you have stock exhaust you'll be in for a long job to remove the exhaust, drop the bell housing and pull the clutch out. Don't skimp on the parts up front, they won't go to waste. If you don't have the money for the whole thing then maybe take the car off the road and wait on it. Just replacing the TOB may quiet it down but six months or a year from now you're going to end up needing a clutch anyway so you might just want to bite the bullet now and get it behind you. If you're like me the worst job to do is the one you've just finished and have to do over.

 

^^ +1 on that good advice .... you'd be a lucky man if the TOB is the only thing that needs attention.

It doesn't take much more time to drop the clutch pack and flywheel ... and get everything spot on.

 

I will present a different view-point...

If you do your own work, and you drive your 928 a couple of thousand miles a year, and the worn but usable clutch disks have lasted for over 100,000 miles, they might be completely functional for another five years.

If you track your 928, or you have spent big bucks on power upgrades, then it might be worth doing it all at once.

 

Good perspectives, all... Thanks!

It is my summer-fun/hobby car - I do a bit here and a bit there. Basically, Wally has pegged my perspective...

The clutch seems to have good bite and all (not that I work it hard), and I know that doesn't tell the whole story (heat stress on PP, disc wear, intermediate plate: God forbid!!!). But, it does look like a reasonably straight forward job, barring a blown pilot bearing... I do my own work and am willing to make a weekend out of it. Have been studying up a lot already. :-D Sounds like fun!!!

I believe PO said the clutch had been done, but no supporting records... So maybe it was done with a crap TOB(?) It seems he took care of rest of the typical things pretty well and it's pretty much in order...

 

have you washed the engine at any time in the past?
If so then you may have washed the TOB as well,
and thus it will quickly rust and fail.
the wash water will run down the top of the block to the rear where the release arm attaches.
then run down the arm to the TOB.

 

Mrmerlin - that is a good point - Yes, that may be at the root of my issue... That doesn't mean the noise will go away with time/use though, does it? I wish it would!

 

The throw out bearing on my 79 sat for at least 2 years and was nice and "woooooosh" sounding when I first got the car running. It has all but gone away since the car started to feel some love again.