Heavy vibration at WOT in 5th gear

[djorgji]

Hi,

I need help with diagnosing lots of juttering coming from the rear at WOT in 5th? The car feels like a rear tire exploded and starts vibrating in the back when I got WOT in 5th.

Is it the clutch or dual mass flywheel? Or anything else?

Also, the juttering happens only when LPG is on, so when more torque is applied.

The car info: "1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection."

Any ideas?

[Alastair]

How are the differential mountings and the flex-discs of the drive-shafts?

These items can cause horrible vibrations at speed when broken....