Turbo17

The easiest thing to do is find a used torque tube and shaft. Replacing the shaft and bearings inside the TT can be done, but it's a pain.

I suspect the damaged part could be chucked into an indexer and the spline slots ground out to clean them up and let the clutch slide along them (or you could bodge it with a Dremel and cutting disk to hand clean out those slots.) There looks to be lots of material still on the splines, so I wouldn't be too worried about grinding out the slots. It might even work to just grind the shaft round in that area and remove the splines completely - depending on where the clutch plate sits.

I'd use a micrometer and check the wear on the tip that fits into the pilot bearing before deciding what to do.

Darud35

I really appreciate all the feedback guys.

The TOB spins freely so I'm going to assume that's ok. Can you elaborate on what to do with the clutch fork? It doesn't seem like i should remove any of the contact material. Should i just clean up the edges?

A guy about an hour from me who has a few to choose from. Any idea on the spec for the pilot bearing and shaft end dimensions? Also, I wonder what caused this. I worry that I'll put a new one in and the same thing will happen. It easily could have been like this during assembly and i wouldn't have noticed. Perhaps a loose pilot fitting allowed too much movement in the shaft?

Turbo17

I was worried that the old worn fork would not properly contact the new TOB. I tried to order one, but it was NLA, so I removed (grinder) the area that wasn't worn, leaving the contact surfaces smooth. I didn't remove any of the surface at the bottom of the worn groove that had previously been contacting the TOB, except for just enough to make it smooth. Whether I needed to do this, I don't know.

I can say that I measured the fork and slave cylinder motion to make sure this was going to be OK. With the fork material worn/ground away, the clutch slave piston has to move slightly deeper into the slave cylinder to take up the slack - but not much. I opened my slave cylinder up and cleaned and refurbished it to make sure there was no rust that would cause the slave piston to jam when it went deeper into part of the cylinder that it hadn't originally been in. There was lots of extra room for that.

Some have built up the fork to repair it (in the wear groves) with a weld bead and grinding, but I was worried it would affect heat treatment and strength. Others have strengthened it at the base of the arms - which is a good idea if you have an aftermarket heavy duty PP. If you have a source for forks, it's your choice. Yours looks a bit more worn than mine, but not much, but a spare is always nice to have.

As to the pilot specs, you might consider contacting the company at the link posted for TT rebuilds, or specs may be in the service manual.

If you figure out what caused your damage, let us all know.

I have to say that I never really figured out why a TOB full of hardened grease would cause clutch dragging on mine. As long as the PP has moved off the clutch disk, the disk should be free to spin. Perhaps mine was somewhat like yours and wouldn't slide smoothly along the splines (although mine wasn't damaged, it was a bit dry). That would cause some dragging. I lubricated, cleaned and replaced everything, and it's been fine for another 5K.

Good luck.

Darud35

Thanks Turbo. I will be sure to keep you all posted. Quick question, is something supposed to release the clutch from the flywheel? The clutch isn't a snug fit inside the TOB on mine. Im assuming once the PP removes pressure from the clutch it pushes from the flywheel (like a brake pad/rotor).

Turbo17

As far as I can tell, the clutch disk just floats inside between the PP and flywheel once PP pressure is removed by the TOB. If the clutch disk can't slide along the splines there will be problems.

Were you able to see any marks anywhere that tell you what caused the damage to the splines? It seems like it would be pretty hard for the splines to hit anything they are supposed to clear, so I was wondering if a rock or something else got wedged in somewhere. I would have expected to find some marks indicating what was doing all that damage.

You might find this link to be useful:
http://www.944online.com/cgi-bin/for...num=1294429473

Darud35

Thanks, that's a good article. I'm not too sure what caused the bad splines. Before I pickup my new driveshaft I'm going to connect the bell housing to the torque tube and try to align everything to verify that it's where the clutch should be moving. If it's not in the "sliding zone" I'm back to square one for diagnoses.

The history of the driveshaft is unknown to me. I bought a full turbo drivetrain setup. When I cracked open the bell housing I found that the clutch had several broken springs. It's possible that one of those got wedged somewhere causing the damage. The splined portion of the clutch could have been a different length, so maybe that setup never had an issue. I didn't look at the shaft before installing but I'm going to assume they were there beforehand. I will keep you posted as I learn more!

Norm Swanberg

The web site for Paragon shows a reconditioned clutch fork is available. I do not know if yours needs to be replaced, or what caused the problem. The rock damaging the splines sounds like as good a guess as any to me. Good luck
Norm

Darud35

An update, I installed the clutch, pressure plate, for and bell housing last night. I had a friend push in the clutch and it was spinning freely! Tonight I picked up my new driveshaft/torque tube. I installed that, and the end of the shaft spins freely when the clutch is engaged. Tomorrow I need to mount the torsion tube, rear suspension, bleed back brakes, install starter and exhaust then it will FINALLY be ready for a test drive! My first drive in the turbo 944

refresh951

Car looks awesome. Nice work.

Wald944

I have a few Clutch questions of my own...
Car has been up on jackstands for 2 months now as I find time to work on it, order parts for WYIT, and study up on forums and tech guides.

#1. I received regular pressure plate bolts 900-067-020-02 even though I ordered the ones for Turbo 999-510-012-02. Both are M8x50, but does anyone know any difference besides the head pattern?
Am I safe to leave them or do I have to dive back in to replace them? (just finish remounting the TT)
Can I replace them through the Bell Housing window, one by one?

#2 My release fork had the same deeper groove from where it had contacted the TOB. However, when I ordered a "reconditioned" unit, the surface was shorter than the wear surface on mine. It was like no material was added. Has anyone had any difficulties with operation, just cleaning up the fork contacts (no grinding or welding)?

#3 For the number of people who experienced their release shaft slipping out of the fork and bell housing, I am surprised that nobody sells the bolt and locknut.
I found the nut on PelicanParts but not sure about the bolt.
Bolt
http://www.pelicanparts.com/cgi-bin/...Plated%20Steel
Locknut
http://www.pelicanparts.com/cgi-bin/...ut%2C%20M6%20-