So as a new member, I did search the forum pretty exhaustively before posting. But to no avail, here we go.
got this c5 about a month ago. PO claims along with all the other work ( crank, pistons, cam etc) that it has a new spec 2 clutch.
the car has tons of little issues. It was rode hard,, put away wet. But it's done what I wanted. A driver.
Sunday night after a good 3 hour highway cruise, moderately hard shakedown I returned to city driving. After getting on it a bit 1-3 started making a pretty decent grinding noise , I drove a bit today and I can replicate it when my foot is in it. When clutch is depressed , during shifts, but will go away once I am in gear and release clutch pedal.
my first instinct is that the throwout bearing is shot. I had some inkling the throw out or pilot bearing had a hum all along.
I checked the fluid for the clutch. Was near full ( coincidentally there is no bracket or anything holding the reservoir in place ) but only took an ounce or 2 to top off.
the car is going into a vette mechanic Tuesday to check a power steering leak and just give it a general once over.
But as a general statement, should I be mentally preparing myself for some serious disassembly at the shop? Or is there a chance something stupid like shifter linkage is binding up etc?

Thanks guys, sorry for the long winded post

 

You should ask these questions in C5 Tech, not here.

 

if my experience is any indication, your instinct about a problem in the throw out bearing might be correct, but it is not often considered a problem spot. I have read the pilot bearing is a little tricky to instal, and getting it wrong is often a problem, plus, some guys just don't like the weak look of the part in association with an LS1.

when my car was apart to correct my drivetrain noise with a new clutch instal, (McCloud, yeah), there was nothing but black clutch dust where the pilot bearing used to be. Some ditch the fragile looking needle bearings in the pilot for a bronze oil bushing, said by some to be worthwhile if you are pushing the car hard, but the bushings don't last as long as rollers. luckily, an OEM pilot bearing is just fine with me, so I don't have to experiment to find the truth of the matter, since I paid to have the thing pulled apart, and it wasn't cheap.

I also had a couple of broken springs in the clutch, with noise on both acceleration and deceleration, none while running in gear, hard to pinpoint the source while driving. disassembly made things pretty obvious, and from the look of things, I am glad I didn't tear a bunch of stuff up from broken parts, it looked very possible, and I let it go longer than I wanted, while searching for a garage I could trust to take apart a C5.

 

So it's in the shop. Mechanic was able to duplicate the noise. Tomorrow it's supposed to be on the lift to try and isolate it. After most my research I was leaning towards pilot bearing. But mechanic said he's leaning towards the torque tube. Naturally the PO said the tube was rebuilt. But, bunch of mods etc. Should have some answers soon and I'll report back.

 

Moved to C5 Tech.

 

so the upside so far is we found some issues. the torque tube is destroyed. and i mean destroyed. I will get some pictures when i get over to the shop. Naturally the PO said the tube was just rebuilt, but i have since watched a few videos where if the inside shaft wasnt seated perfect, it could walk and then destroy itself. At this point its looking like thats the case.

On the upside, it appears that it is in fact a spec clutch inside the bellhousing. We are trying to avoid pulling the bellhousing if possible. but will make that decision a little later today.
Right now it is all about deciding if the inner shaft cut into the tube itself enough to trash it. or if anything is salvageable.

while taking it apart, it was noted that the slave cylinder has a thicker spacer, which is not uncommon, but likely explains why the clutch releases so high in the travel. Does anyone have experience with setting this gap? is it incremental adjustment depending on spacer thickness? it would be nice to get the clutch engagement closer to the floor, without having it constantly dragging naturally.

 

Maybe they left out the giant snap ring or a guibo came apart? I've also heard an over rev can cause it jump rope and lead to premature failure.

The whole thing fit together pretty snugly when I did mine last month. I pressed new bearings and eliminated the guibos with a longer shaft.
My spec clutch (3+) came with a guide on a sheet of paper for measuring the travel distance of the throw-out bearing and comparing it to the height of the fully engaged clutch.
I want to say the spacer I put in measured in the ~.200" area.

Ideally that would be dialed in per the sheet, but you could then adjust pedal position with an adjustable master cylinder. The Tick one puts a turnbuckle on the pedal connection that you can lengthen or shorten to your liking.

 

I have a rebuilt tube on the way. Once it's in I think down the road I may do the tick master.

 

some pictures of the torque tube after removal. replacement going back in today

 

replacement tube came in yesterday. seems like it may have been damaged in shipping. the almost brand new input shaft seems to have a little wobble to it. easy fix i can take the input from my old one. the part that is troubling. spinning the input by hand produced a clunk in the shaft during revolution. the tube is basically an amplifier, so its tough to pin down.
Here is where it gets weird. if we remove the large clip from the tail section, the clunk goes away. clip reinstalled, clunk returns. seems to be the bearings in the tail section are toast.
hoping to have the bearings swapped out and the tube back in today.

 

Update, again. Couldn't get this mystery clunk to go away. The mechanic I'm at, works on allot of vettes. But at this point I'm not thrilled. He's an OEM parts type. And I'm not interested in am OEM TT for $2500. So we think the shaft itself is tweaked.
at this point between desperation and lack of c5 parts on shelves, I pulled the trigger on DSS carbon fiber. Seems the people who run them love it.
it should be here Tuesday. I know the shop is as anxious as me.
Fingers crossed this thing spins noise free and I can be on my way.

 

New carbon fiber shaft made to length installed.
solid couplers both ends. God awful noise is gone.
A huge hassle to get this finished. And naturally a bunch of other repairs while apart. Rear tie rods. Diff mount. Bunch of misc hardware.
the solid prop shaft does have some vibration. But after a few hours and about 200 miles, I found the sweet spots where it isn't bad.

 

I'm still trying to figure out how you can "not get it seated perfectly". It's held in by a giant snap ring. If the snap ring is in place, you have everything where it needs to be. I'm more inclined to thing that the previous owner just flat out lied about the tube being rebuilt.

 

I have no way of knowing that. He said it was. I asked again, said the same thing.
what I did learn having 2 entire TT side by side and apart. There is some inconsistencies with prop shafts when gm installed them.
Either way, not a cheap or fun fix. But I do have some solid aluminum couplers I'll be listing tomorrow.