So I have an ‘00 c5 coupe as my daily driver with a t56, 115k miles, and it has a ton of issues/quirks with the drivetrain. I’ll be completely redoing the valve train and bolt ons of my ls1 soon (custom grind cam, ported heads, ported ls6 intake, ls2 tb, catless x pipe and headers, etc.) and I know that my drivetrain won’t survive it. I don’t make a lot of extra money to spend on rebuilding stuff at a shop so I’m trying to do this on my own or with a few friends in my garage. Don’t really know what the root cause/s would be, and I just want to know where to look to fix these problems when I take everything apart. I’ve listed all the problems I can think of and included the previous owner’s input below:

• shift linkage feels extremely notchy, notably feels like there’s a ‘halfway point’ when going from neutral to all the way in gear (car also came with a Hinson Motorsports short throw shifter I coincidentally recognized at summit)
• At high speed shifts starting from the top of 3rd (5,700-6,000rpm) into 4th and top of 4th into 5th, clutch sometimes and most times now gets very heavy and the pedal sticks to the floor with maybe 1/4” of travel, clutch feels like it won’t fully disengage and can’t shift into next gear followed by grinding if I try to shift into any gear. I have to let the car coast in neutral for a while with my foot off the clutch pedal and then the pedal will slowly rise up from the floor
• 1st gear pops out when leaving from a stop sometimes
• Whine coming from rear (don’t know if it’s transmission or diff related), gets louder in higher gears cruising on highway but most notably in 4th-6th
• Rattle or chatter coming from what sounds like the torque tube when in neutral with the clutch released, the sound goes away with the clutch depressed. Don’t know if it’s normal as I’ve heard different things.
• 2nd gear grinds coming from 1st or 3rd, have to wait about a second in neutral to shift without grinding and feels very notchy
• 4th has also started to feel very notchy and sometimes grinds coming from 3rd gear at reasonably high rpm (3,500-5,000)
• Sometimes in 1st gear the clutch engagement point randomly changes to be as soon as I pull my foot back at all after coming to a stop
• Previous owner said car has a “racing clutch,” don’t know what kind because I guess he didn’t know, could be stock but it feels really f*cking heavy

Any input is appreciated, I’ve never done any of this stuff before, only ever rebuilt a k series Honda motor and done various maintenance stuff myself and just want to keep things cheap.

 

I mean, that's a lot. You could try flushing the clutch fluid or installing a new master cylinder to see if that resolved the clutch drop problem at high rpm. But it sounds like the guibos or bearings are going in the TT. And it sounds like the T56 guts are turning to mush. A fluid flush can't hurt and is easy and affordable. Fresh trans and diff fluid.

But really... all said... there are enough variables at play that SOMETHING is going to need replacing and that means taking the drivetrain down and out of the car.

Your transmission still works technically and can be sold for 750 to 1000 realistically. A lower miles one can be had for 1500 to 2000 if you shop and that beats a full rebuild cost. As well as no need to pull it, send it out, wait for it to come back. TT can be fully rebuilt easily and cheaply if you have a friend with a press to handle the bearing removal and install. If your car is 2000 then you have a 10mm TT. I recommend shopping for a 12mm from a 2001-2004 and rebuilding that prior to removing the drivetrain, then slapping it in. If you're going to drive the car hard it IS a notable upgrade in durability. I have sheared the bolts off my original 10mm and shredded guibos.

For all the work done for the TT and trans exchange, I mean with everything down it is probably wise to check the existing clutch for wear and have a plan in mind for replacing it if need be.

But man.... trans net expense 1k or more, new tube plus fresh guibos and bearings 600, and then potential for new flywheel/clutch/slave adds up at least another 600 to 1600. Depending on general condition of the car vs the labor and expense, some might consider selling one car and buying another in cleaner condition as a better potential foundation for a build. Or just presume that when you get to heads/cam or blower, you're going to need/want to have done this work and investment in the drivetrain already.

 

This is one of those if I could drive it I could help more deals.
Get ready to spend some cash

The clutch pedal to the floor is a common C5 issue. The fix is a Tick master cylinder.

Since the previous owner told you it has a racing clutch we will go ahead and call him an idiot. It’s hard to say what he meant by that comment. Maybe a unsprung disk maybe a twin disk ?
It’s very easy to unbolt the inspection cover and take a peak. It would help to know what disk and pressure plate is in the car.

The first gear popping out could be from the shifter or linkage adjustment.


96,000 originals

The Grinding
Well it could be the same as above. The more likely cause is the previous owner was using his “ racing clutch”. and your synchros are toast.

Lastly on the torque tube. Hopefully when the clutch was done the tube had a refresh with new bearings and couplers. If not then you’ll be doing that. If they are the originals then your on borrowed time IMO.

 

I was re-reading the post
Your torque tube may not be the issue with the noise. It may be the clutch. Twin disk clutch’s are often noisy. With any luck maybe that is what you have.
Pull that cover
Also the throw out bearing may be making noise