So I swapped a '96 T-56 into my 1984 Z28 with a crate Vortec headed long block, using a SPEC stage 3+ clutch (that was lightly used), new pilot bearing, resurfaced '96 flywheel, and new GM hydraulics. The car and manual worked great for a few thousand miles. My problem is now that when the car is warmed up, there's a stuck-pig squeal coming from inside the bellhousing. It isn't affected by clutch travel, being in neutral or in gear, and it's driving me insane. The ONLY way to get rid of the squeal once it's warmed up and starts making the noise is to load the engine in a high gear, like doing 30 in 5th and hitting the gas pretty heavy. I've already replaced the pilot a second time and TOB. Any ideas would be great. Thanks!

 

Using an LT1 style flywheel & clutch, I assume.
What lube was used between the TB brg & the throwout sleeve?

The noise isn't disappearing in 4th gear, so it's not the maindrive to mainshaft bearing, and it sounds like the noise is there while stopped so it's not the front adapter to input maindrive bearing.

When the clutch is not slipping, the pilot of the input maindrive shaft isn't spinning in the pilot bearing / bushing so that's not it.

The TO brg. is always spinning on the throwout sleeve. I'd be looking at mic'ing those parts and looking for interference at their operational surfaces. Machinist dye might help you see where things are rubbing while it's apart, but a non-contact light thermometer could possibly see heat at those parts if the slave & spacer were out.

Don't have a sleeve on an LT1 box out of a car to measure for you at this time.

How's your mpg and what rear gears are you running? Happy w/ the combo so far?

 

Originally I used white wheel bearing and disc brake grease, then when I installed the new Tob I used black moly grease. I just recently swapped in 4.10 gears and an Eaton posi, but that was post-tranny noise and I won't drive it with it squealing. Before that it had 3.23's and I got around 26 highway running a little rich. First gear is a lot more user friendly with the 4.10's. I love the setup minus the squeal and someone hit and ran my passenger quarter panel really hard and I haven't decided what to do with the car anymore. But the squeal just claws at my brain.

 

Just thought I'd give an update to this ancient thread. Two throwout bearings, 3 pilot bearings and many inappropriate phrases later I found the noise to be caused by a valve cover breather that was stuck shut.

 

Poor TO bearings get blamed for everything, I tell ya.