Hi all,

I recently changed my 89 GTUs' transmission to a miata gearset, due to what I thought was a bad throwout bearing and shot transmission (lots of whine in every gear but 4th). Along with the transmission, I had the shop install an Exedy Stage 1 clutch, RB aluminum flywheel, Mazdacomp transmission mounts, a new crossmember and OEM throwout and pilot bearings.
(Long story short, it was a nightmare with the shop doing the work, and I won't be going back there again)


However, I noticed that when I rev match above 3.5K rpm, there is a vibration in the clutch pedal that seems to match with engine speed. I was able to replicate this with the car in neutral, clutch depressed and revving to 4k rpm.

From my research it leads me to think it is the throwout bearing misaligned or the clutch pressure plate fingers not being aligned. The car does make a whirring noise in neutral that goes away with the clutch depressed (which leads me to believe that it is the TOB).

Has anyone else experienced this issue or can shine some light on it? I just want to make sure I get all my ducks in a row before I go to a different shop for the repair work.

 

>>>>I recently changed my 89 GTUs' transmission to a miata gearset<<<<<

Was that tested and working before the clutch was changed?

 

They were swapped at the same time, but I do know the Miata gearset was good before it went into the FC. It came out of my old Miata.

 

pull the inspection plug and be sure the flywheel is spinning true, if it is then i would suspect the clutch either was improperly installed or is defective.

only other reason i can think of that would cause it is if the pilot bearing was missing and the input shaft is misaligned.