[Crumpler]

Hey guys.
Discovered a rattle after a pretty aggressive track day.
It is coming from the bell housing area.
I’m hoping it is beRing noise of some kind.
It is only notable in neutral, with clutch engaged.
I think only when not rolling.
Meaning goes away when I push pedal in.
Throw out or torque tube bearings?
It would make sense, TT original to car and the ten pounds of boost probably not kind on it.
What else would you look at?

Edit: clutch operation is normal, no slip no lurch.

[worf]

release arm ball cup bushing

try this for the smoking gun:

In neutral, stopped, clutch engaged (foot not on pedal), at idle (so that you hear…)

- do you hear the rattle?
- when you put slight load on the clutch pedal… just take up the free play…
- does the rattle go away?

[worf]

Your terms are ambiguous.

Thread title says: forward transaxle area.

Text says: bell housing.

Those are on opposite ends of the torque tube.

[Crumpler]

Thanks for following Worf.
Rattle is forward of gear shifter, sounds under dash.

Noise in neutral, not moving.
Noise only stops when pedal all the way down.

[Crumpler]

I’m into the meat of it now.
The ball socket bushing is toast. I can move the release lever on and off freely. The release bearing is also has alot of play in it.

Here’s my next issue.
I can’t slide the coupler back far enough to free the short drive shaft.
It looks like it’s hitting a TT bearing?
Do they migrate with time ? And what is the move?

[worf]

Torque tube noise. No doubt. It goes away when the driveshaft isn’t spinning and/or when it isn’t loaded by engine power.

TT Bearings. I-shaft guide tube. Pinch clamp bolts. It could be clutch pack related, but, it sounds to me exactly like TT bearings and/or carriers that have lost too many molecules over the last almost 40 years.

I hesitate to make a $-sink diagnosis over the int3rw3bs before you inspect anything, but …
If the TT’s never been rebuilt, R&R it and send it to Constantine. Not wasted money. Stuff inside it are wear items.

[worf]

The ball socket bushing is toast. I can move the release lever on and off freely. The release bearing is also has alot of play in it.

The release bearing/arm/PP interface has a lot of slop in it even new. Diagnosis not conclusive until it's on a bench. Or, IOWs, I haven't seen a t/o bearing so bad that it was obvious with the assembly installed.

I can’t slide the coupler back far enough to free the short drive shaft.

First problem is that the i-shaft is about 3/4" "pulled out" towards the rear. With both pinch bolts in place the clamp for the i-shaft-side of the tube is almost hitting the bolts for the guide tube.

Get the i-shaft nose pushed back into the pilot bearing. That'll give you a bit more room to work. But, not enough to get the assembly out ...

It looks like it’s hitting a TT bearing?

... because it does, indeed appear, that the TT bearing carrier has migrated forward. It would appear that you pulled the clamp tube forward to take the picture. It appears that the carrier is forward enough to occlude some of the drive shaft splines.

Do they migrate with time ?

Time-based degradation of the rubber around the perimeter of the bearing carrier and the bearing itself.

But yes, once the carriers migrate you get increase vibration. Increased vibration destroys the bearings and pieces fall off inside the TT. In some cases you can hear and feel the carriers sliding back and forth on the shaft during acceleration/deceleration.

And what is the move?

First, never, ever, pry on the clamps on the pinch tube. They are spot-welded and a pry bar can break the welds.

Hammer. Long tool (e.g. 1-foot long punch, or some 3/8" extensions plugged together, etc.)

More specifically, see if you can tap the bearing/carrier rearwards.

If there's no way to get the pinch clamp tube back far enough, then the next step is:

- remove the four upper bell housing bolts.
- remove transaxle mount bolts.
- detach e-brake cable from transaxle carrier or disconnect cable from handle in interior (to avoid stretching e-brake cable)
- slide TT/Transaxle assembly back an inch-ish (you'll run out of room before mounts will slip off of carrier)
- and you will likely have some problems getting the upper bell housing unstuck from the engine.

... and then see if you've got room.

With the i-shaft pushed back in, transaxle pushed aft, you might *just* have enough room to drop the clutch.

I don't know for certain; I've never had drop a clutch this way.

You will want to put a floor jack under the front of the oil pan before you pull back the TT assembly: the motor will droop forward considerably and if you have non-Porsche motor mounts (e.g. ford, anchor, volvo, etc.) they can be destroyed with prolonged 'droop' of the motor. You will also want to make sure nothing else gets hit/stretched/crimp if/when the motor droops forward.

[Crumpler]

Thanks Dave.
I appreciate the time you are taking to walk me through this job.
I was able to use the coupler like a slide hammer and tap the TT bearing back far enough. Got the clutch out using the WSM walk through. The two smaller centering pins were a bitch to move.
Anyway, I’m going to replace clutch and replace all wear items. I will pull the TT as well and have it rebuilt.

[worf]

Trick for next time: you don’t have to remove the starter. Just back the bolts out until they’re hanging by 2 threads, slide the starter back and use a shim to keep it from sliding back in. That moves the gear back far enough that it won’t interfere with the pressure plate. (This, if you are using the little U-shaped pre-load “wires” shown in the WSM.)

[worf]

@Crumpler Do you still have driving/racing to do this season? If not, wanna be a guinea pig for something that will be more useful to you than worrying about the intermediate plate wear?

At a minimum... while you have the assembly out... can you take a measurement for me?

[Crumpler]

Season is over.
I’m game :)

[worf]

Season is over.
I’m game :)

PM me your phone number and a good time for me to call after 3:30 EDT.

[Crumpler]

With everything on the bench, the throw out bearing was good. The bushing for the release arm socket was totally absent.
The TT bearings are barely friction fit, with very little effort needed to migrate them around on the shaft.
The clutch disks were ok.
WSM says they are good until 0.3 mm? That sounds ridiculous.
Also ridiculous was the amount of slop present in normal conditions with the release arm and throw out bearing. As Worf mentioned.
Removal was overall a messy job put not terrible.
I bet you a dollar the GT3 owners don’t look like this:

[worf]

Painters hood. And safety glasses.

And, I’ll tell ya now: if your wife didn’t QC your wash job on the way out of the shower, you missed a spot (or five.)

Last time, I forgot the painters hood, finished showering at about 3 AM, didn’t wake CarChick up to check (not worth my life that) and the next morning my pillow case was black with carbon dust.

[mr928]

The centering nub on the TOB thrust washer is worn off

[Crumpler]

Thanks Mark.
What does it look like unmolested? I can’t make out specifics in PET or WSM.

Actually, did the throw out bearing or the release arm change MY 86-87?
I think we established the bell housing did not.