390se vibration

[sphs2]

Hi all, got a bit of a vibration issue.
It starts at around 55-60mph and is quite bad when cruising although you don't notice it when accelerating.
I have changed the half shaft uj's and had the wheels balanced, they is also sometimes a knocking kind of noise from the rear now and again but not all the time, it usually shows itself shortly after take off but not on take off.
Ant ideas!

[jmorgan]

Wheel bearing? Also I had a wheel that had the center hole out of true and had to get them balanced on the bolt holes. But that showed up on balancing.

[ed_crouch]

If its a dull thud (the occasional knock), it might be the roof panel falling forwards against the spare wheel. It'll very definitely have tipped aft "on takeoff"!

Could be clonky UJs, you can tell by jacking the car up and grasping the wheel at 6 & 12 oclock and rocking it quite firmly up and down. There will be perhaps 1-2mm of wheel movement, but no more. If it moves much more up-down than side-side (like more than the normal 1-2mm), you have an issue.

HTH.

Ed.

[rev-erend]

Buckled wheel !

[grahamw48]

Exhaust ?

..Talking of roof panels moving about.

I use a cheap plastic football jammed in the gap...keeps everything in place without leaving marks...oh, and you can have a game of footy with it when you're feeling energetic.