Stick Shift Vibration in 5th at 80mph

ASSISTANCE Stock Engine-Bay Components
1

Hi all,

I’ve searched for this problem, but haven’t found anything dealing with it specifically.

Title pretty much says it all. When I’m driving my 93 RS on the highway in 5th gear, as I approach 80mph my stick shift starts vibrating significantly. This isn’t normal engine/transmission vibration. It resonates somewhat loudly at around 3 - 4 pulses per second. When I slow down to about 77mph it goes away.

I recently flushed the transmission fluid and refilled with the best fluid recommended on these forums. In all other ways it runs and shifts completely smooth with very little to no noise.

Something in my head suggests “bearing failure is in your future”, but since I’m not experienced working on transmissions I thought I’d get your feedback.

Any help greatly appreciated. Thought I’d get some experienced opinions so I’m informed and then take it to the local transmission specialist.

Thanks guys

eris

2

5th gear and 3rd gear run on all the same bearings from crankshaft to the wheels, so run your car at the corresponding engine rpm for this problem in 5th but for 3rd gear.
Take a quick peek at your front wheels, make sure the wheel weights are still there. Inspect your motor mounts.

3

I 2nd the wheels / tires as well, check for any wear abnormalities. If none are found, do a balancing and possible alingnment, this should make a difference in your vibration.