Whats that rattling noise from my manual tranny upon acceleration?
This is a common problem among 6-speed cars. GM is aware of the problem. The faint but distinct rattling noise can usually be heard with the tranny in neutral and the clutch out. A few quick revs at about 1/8 throttle and it should get louder for a fraction of a second, then disappear, and then return when the engine drops back to idle. You should also be able to hear it when starting out in first from 0-10 mph. Unfortunately, there’s no Technical Service Bulletin or recall to address this problem. But GM does know about it. In 1993 and 1994 cars, the GM Tech Assistant Group (TAN) called for the dealer to replace the clutch with a revised one. Two different part numbers for the revised clutch were found, (12551803 and 12551809), but no one is sure which is correct or if they really exist. 1995 and later cars are supposed to have a revised clutch (part #12551309), however, even people with these cars report to have same rattling noise. As of now, there seems to be no fix for the problem
