Car Vibration need help please.

[Hillbilly]

My car has a severe vibration problem, simply put when I drive along starting in first gear its fine shift to 2nd it vibrates mildly at about 3000rpm shift to 3rd vibe comes in at same rev and mild, shift to 4th get to 3000 or there abouts vibration starts and gets pretty bad to about 4500 shift 5th and it goes away until it gets to the usual rpm and then starts again. This could be easy to explain and fix except if I drive along in 4th or 5th gear get to the rpm where it vibrates then stick my foot on the clutch and hold the revs at about 3500 the vibration goes away. Drive shaft is 1 piece unit is brand new and has been returned and tested and is fine. Only thing I can think of is there is a problem with the gearbox(R154 supra 5 speed). Mounts are all new as is the clutch.
Any Ideas would be great as I have run out of them.
Cheers in advance.......

 

[okbobbo]

Check the flexible coupling for cracks and also check for broken trans mounts. Good luck

 

[stevechumo]

I think I read somewhere on other forums and 1 guy had the similar problem. It turned out to be a bad tranny. If you have the new mounts and drive shaft, then these shouldn't be the problem. Check the alignment of the tranny with the driveshaft. I think that's the second problem I read about.