Bad wobble under engine load??

Soldato
Joined
18 Oct 2002
Posts
4,023
Location
Wellington, NZ
Recently i've developed a bad wobble rather than vibration when the engine is under load. It seems to be worse at lower RPM in a higher gear when the engine has to work hardest.

If i'm on the motorway and at 70, slow down to say 40 then accelerate again it's really bad, shakes the car + gearstick etc, and the wheel jitters. It doesn't feel like your average wheel unbalance.

It's like a low frequency wobble and again it's worse uphill. It won't do it at really low speeds or if i put it in neutral and rev at say 70mph it won't do it.

Engine mounts seem fine (only one I haven't checked is dogbone, but it looks ok)
Driveshafts were changed not long ago.
Wheels were balanced with new tyres about 3 weeks ago.
Tracking is a tiny bit out (had it tracked about 1month a go)
New wishbones + balljoints not long ago
Don't think discs are warped but does it when driving normally anyway
Wheel + hub nuts ok

Anything else I can check or recheck as it's making motorway driving a nightmare!! Also this may sound daft but it seems to get worse after it's been driven a bit?

Any help appreciated!
 
Sounds like something is getting unhappy when a lot of torque is being put through it. If the driveshafts were changed recently, that would be the first place to look IMO.
 
Have you checked the tie-bar bushes?

The 420 was a real bitch to keep in a straight line. It'd be wobbling all over the show at speed yet fine upto 60mph.

When I took the bushes out of the subframe to polybush the mounts they were very very soft and had loads of cracks in.

Probably not, but worth a check.
 
Dogbreath, the driveshafts have been fine all this time until now. Checked all the rubbers, bolts, no play in inner or outer joints as far as i'm aware.

AGW: I'll have a look, i don't ever recall changing tie bar bushes.

cheers.
 
img3988dl1.jpg


Ok discovered this today. The question is why is that manifold heatshield so far back that it's touching the gaiter? I actually noticed that a while a go but thought it would settle back once the car had been dropped! DOH. Luckily it's an quick easy job as it's not the gearbox side!

Thanks for the help :)

edit "Partial seizure causes a strange "pattering" sensation through the suspension. It is caused by the joint overheating, which in turn is usually caused by the outer joint gaiter having split, allowing the joint to throw out its grease." (wikipedia) It mentions only the outer joint but does the same apply to the inner one too?
 
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