Thread: Vibration at 80km/h and 99km/h.

Originally Posted by PeterH

I have heard about the flex plate causing something like this, can someone explain to me exactly what that is and what is involved in fixing it.

I too would like to learn more about the flex plate issue. Hopefully one of the more enlighted folks around here will explain.

My money is on wheel balance and/or alignment, maybe a uni joint.

Cheers, Paul.

Yes a wheel balance did occur to me, possibly alignment too, although it does drive pretty straight.
On the Classics you could do your own wheel alignment fairly easily, I even made myself a purpose built measure, worked a treat! ... is that the case with P38's, or is it much more involved?

cool, I'd like to learn about that too

Hey Paul, here is a great link I found to doing your own wheel alignment on a classic, thought you might like a read....

Last updated

Cheers, Pete.

viscous coupling possibility...

Put transfer case in "neutral" ...consult owner's manual...requires the spare 5 amp fuse under driver's seat to be placed in empty slot #11. Turn ignition key to stage 2 (not start), then turn off ignition...message panel should say T/F case in neutral. Raise one front wheel with jack and release handbrake, A/T in "park". Now try and rotate raised front wheel... if you can turn it albeit slowly OK, if not...viscous coupling is shot (pls don't ask me how I know this ). Don't forget to remove the fuse from slot #11 .

A shot VC will cause noticeable seat of the pants vibration in car at anywhere between 80 and 110 kmh as you describe due to transmission wind-up ...you may also feel the vehicle turn "roughly" when making a U-turn...

Hope it is not a shot VC...but it's worth checking out

Originally Posted by PeterH

Yes a wheel balance did occur to me, possibly alignment too, although it does drive pretty straight.

Wheel alignment won't cause vibration issues.