Hi I was wondering if anyone knew of a solution for when you accelerate from say like 40km to 80km the car starts shaking. The steering wheel DOESN'T shake so would that rule out drive shafts?

It shakes like under my seat so like i can feel my seat shake / vibrate.

I have just changed my gear box and the middle plate of the clutch. Car done 202,000km. The dealer said that when checked after installation it didn't need alligning.

Any thoughts????