SharkSkin

Odd, I thought they were all the same, with 6 bolts.

SharkSkin

Bill, 5 speed cars have 3 pinch bolts on the drive shaft. I was referring to the middle one.

Charley B

Place your bets gentlemen. Round and round she goes, where she stops, nobody knows.

SharkSkin

One chip on red, one on black... I still get to play, and there's no downside.

vwdmc16

maybe there is. so ive taken a look at the clutch, removing the lower bellhousing i found just one 2.5" long scratch in the aluminum that is fresh. other than that there is no visible damage. all 9 PP bolts are in, both TT coupler bolts are in. the throw out bearing support and its little 6mm bolts are tight. the throw out bearing is tight, i pushed and pulled on it, its secured well. the front TT carrier bearing is fine looking but it is pretty near the TT coupler, not touching but close to the end of the tube, is that normal?. the only thing out of place is that there is a bit more than usual play in the clutch disc splines to the intermediate shaft, about 1.5-2' or play in the shaft splines. but i doubt that is the noise. i stuck a boroscope in between the PP springs and saw no damage either. the only thing out of place was a power steering bracket bolt was a bit loose. so next ill cut open the oil filter, and make sure there is no internal damage showing up in the oil.

Charley B

I believe that front TT bearing should be about 10" in from the front.

Have you started it to see when exactly the noise is present, and if clutch in/clutch out etc. makes a difference? I realize that with a racket going on, it can be a little touchy to fire it up.

SharkSkin

No, that's not normal. It should be about 1' back from the flange. This may very well be the problem. Push it back to the 1' distance and see how it behaves. If the problem goes away, I would consider your actions to be a diagnosis rather than a fix, if you get my meaning.

With the carrier that far forward, the shaft is no longer supported by the bearing, there is considerable clearance and it was probably whipping around. Below is a pic of where I found my front carrier(too far forward):



Below is the driveshaft; the shiny section just left of the step-down is where the carrier was riding, and to the left of that between the coupler and ball cup you can see where it was originally.



With the carrier far enough forward to almost touch the coupler, it's several inches forward of where mine was and that means trouble. If you are very, very lucky, the inserts that ride inside the bearings and support the drive shaft are not beaten to pieces. They are a thin metal collar with a plastic liner that gets brittle with age:



There is, of course, an improved carrier available.

Bill Ball

Normally a TT bearing that has migrated forward will only cause vibration. But perhaps the bearing has come apart and some loose parts are bouncing around.

Just where is that 2.5" scratch?

Mrmerlin

I wonder if one of the guide tube bolts has come loose

IcemanG17

Hmm this is VERY interesting.....the front TT bearing migrated forwards and somehow caused a problem...but what caused the scratch in the bellhousing....it had to be part of the front TT bearing bracket of the unlikely that a rock somehow got in there.....but then were did it go?

Sounds like an upgraded TT will fix things

Mrmerlin

Brian wat was the last thing you fixed?? remember the release arm bushing, any chance the part may have broken and dropped down??

Aspkiller

After seeing pictures of my car posted by Brian, I decided I might as well join the group.

As to the air intake, keep in mind that this car is very early in its' development. We are currently building the splitter and will change the cold air intake route as a part of its' design. We also have a lot of work to do on suspension, based on the Thunderhill weekend. Slipping and sliding is great for drifting, but it makes for a scary ride on the track.

SharkSkin

Everything... 2/6 rod failure IIRC. So the clutch was off the flywheel and the engine itself was apart.

IcemanG17

The last thing we did prior to the track day was fixing the clutch, which was not working properly due to a bent ball stocket and "gone" bushing on the release arm.....but that all went back together fine.....and the old parts were thrown in the trash...but the plastic bushing was nowhere to be found, however it couldn't make a noise like that

Since the TT did make noise the track day BEFORE this happened...I guess its possible it was already dying, however I have never heard one that got that bad that quickly?

IcemanG17

Welcome to the shark tank....sorry if I posted your 928 too soon, its just so sweet I had to show everyone!!!

So the good news is at least 1 928 survived the track day intact!! How was the rest of the weekend?