I have a 1994 Z28 with almost 120,000 miles on the original transmission. When I shift from 1st to 2nd going at low speeds (5-10mph) there’s alot of vibration (enough to shake the car) as I let off the clutch. It doesn’t happen all the time, but it does happen whether the trans is hot or cold. What could this be the cause of this?
How old is the clutch?
I had the clutch replaced less than a year ago.
Offhand, sounds like a clutch chatter. Hopefully they replaced the throw-out bearing and pressure plate also, along with making double sure the original flywheel is not scored, burnt, or distorted.
A faulty flywheel could do it and so could a leaking oil leak that leads to disc contamination.
If the car has been hammered a bit with a little street racing it’s also possible the disc could be glazed.
The clutch may be adjusted to grab too near the floor. This usually causes the shake when starting in first gear, but I will bet that it is possible only in second. You could have a bad engine or transmission mount too. Pure guesswork by me. Even so; it may be worth checking.