Urgent help needed very strange vibrations

[fatboy_v6]

This is very weird and i've never experienced anything like this before. At about 40 mph + my cally developes a weird vibrating but it comes and goes. Gets worse when i corner right and disappears when i corner left, but comes and goes when i travel in a straight line at a constant speed. Both ball joints were done for the mot so they're fine as is the anti roll bar link on the drivers side coz that was replaced too. It's far too violent for wheels being off balance and my mechanic can't see anything obvious and he's bemused as to why it comes and goes. Only started after the mot. Has anybody got any ideas as i have to sell her soon and i obviously don't want to sell her in this condition added to the fact that no-one will buy her like this.
Please very desperate.

[projectx]

Have you checked the tightness of your wheel nuts? I've known MOT centres to take your wheels off to check your brake bads etc., so they might not have done one of your wheels back up properly...And remember, if this is the problem, the wheel may feel tight because you've been driving on it, even when it isn't.

I had a similar sounding problem a while back..
Hope this helps.

[fatboy_v6]

Well my mechanic had it up in the air on saturday and there was no movement in either wheel but i'll check again just to make sure.

[hoglabs]

If you have 17" aftermarket wheels then I'm guessing that your wheels use spigot rings to mount them ?
If so take the wheels off and check the spigot rings.
The plastic ones can break apart and I've seen a garage trying to refit the broken 'pieces' before now.

[Robert_Dale]

yeh check your sprigots mate

[Furey]

the reason it comes and goes might be because of the change in road surface. at 40mph you may have a harmonic vibration on some surfaces and not another. not that that will rectify the problem but it might help explain it.

[fatboy_v6]

I will check those spigot rings cheers. It only started happening after the mot so i'm sure it's something they've done to it.

[fatboy_v6]

Ok i've checked the spigot rings and they're all intact and in place. Still scratching my head but she's going back in on monday to a different garage. They think it might be something to do with where the driveshaft goes into the hub and the three bearings in there. They think ones out of place or broken does that sound right?

[AndiSe5]

Check the lower rear wishbone bushs mate, these are prone to colapsing (like mine did).

I had simular prob.

[fatboy_v6]

Ok this is really f***ing me off now. I've still got the vibrations. Ruled out so far are ball joints and all wishbone bushes. C V joints. Obvious suspension damage. I've had 3 mechanics working on it and they can't find anything loose or damaged or broken. At this rate it's gonna cost me more to get fixed than the cars worth! Please has any1 got any clues?

[Stupink]

I've seen quite a few of these "vibration" threeds.. do a search for a few more ideas [img]/smile.gif[/img]

I have to go now so i don't have time to type anything, but unless you hit anything to bend anything you're looking at mounts/bushes.. lower control arm front/back, steering rack mounts/play in rack, top stutt mounts, hub bearings should b noisy if problematic i'd think. just drive it roudn to diff garages mate and ask them to have a look like no one has yet [img]/wink.gif[/img] they probably wont charge, try 3-4 untill one finds it lol

[fatboy_v6]

I did try that before i put this up but i couldn't find anything that sounded anything like the troubles i've got. It's the coming and going of the vibrations that puzzles me. Been in the garage again today and had the cv joint on the other side done but that made no difference. The mechanic is convinced it's something on the drive but he dosen't know what.

[Kieran_Burns]

Dumb thing to try (I seem to keep coming up with these) - checks your tyre pressures (especially the front ones) I had a similar problem recently and it turned out to be low tyre pressure in the drivers front one.

[fatboy_v6]

I've already tried that. All the obvious and dumb stuffs been checked. You know how it feel when you've got a wheel out of balance? Well this is a lot more violent than that. It really shakes the whole front end of the car and it'd scare the crap out of ya if you weren't expecting it. It's nothing to do with changes in road surface coz it comes and goes at a steady speed on the same surface. When i say it comes and goes i mean it's vibrating then it'll stop for about 5 or 6 seconds then it's back again for a few minutes. But it's always there when you turn to the right at anything above 45mph and it dosen't have to be much lock either. 3 mechanics have been scratching their heads over this one so all the stupid little things have been done. Could it be the gearbox? Differential? Surely if it was engine mounts or steering rack or bushes or bearings it would be there all the time?

[fatboy_v6]

Ok latest update. Both front wishbones just been changed to rule out the bushes and possible ill fitting of the ball joints and it's still doing exactly the same! I've just about ran out of options and hair to pull out. Really don't know where to look next and it's stressing me out now. Does anyone have any other ideas?