High Speed Shake

[oliver261]

at speed (85+ - for overtaking, maybe) im getting a violent shake throughout the car.

having had the wheels balanced there is little wobble in the steering wheel, it is felt through my feet on the floor, but is violent enough to feel it though the whole seat and make it impossible to drive at that speed, as its so uncomfortable but equally as im anxious the car is about tear apart.

it isn't accompanied by any unusual noises.

i had a full service within the last couple months and the VSR mentioned nothing suspension related, with the wheels discounted does anyone have any suggestions what the problem might be or tips to narrow it down

Regard

Oliver

[steve2006]

Have you checked the engine and transmission mounts,diff mounts,propshaft ujs and rubber joints?

[mr2lad]

I have the same problem on my mk4 LS...... Narrowed it down to 1 possible suspect

Believe it's the props shaft centre bearing ..... Parts about £175 and exhaust has to come off and prop shaft to fit...

I originally thought it was tyres then wheels then brakes ,suspension, but after renewing all of those still the shake so just left with centre prop bearing...as my LS is a second car for me I'm not in too much of a hurry to sort but will be doing it myself later on this summer

[mikeyv]

Another vote for propshaft here.

Don't put the job off, the vibration can harm other components, and if the joint lets go, the prop can dig in to the tarmac - nasty.

[mr2lad]

Another vote for propshaft here.

Don't put the job off, the vibration can harm other components, and if the joint lets go, the prop can dig in to the tarmac - nasty.

That's why mines now parked up...can just imagine damage if bearing failed n prop goes like a Exocet missile SOMEWHERE either up into car or Tarmac or another car/ pedestrian bit OTT but could happen

[Ruud]

I had this issue on my MKIV as well, except it started shaking at 75mph. Had all 4 wheels balanced, twice. No difference.

I also suspected mounts etc. I just wanted to make sure it wasn't anything simple so with the help of the spare wheel, I just started swapping wheels and took it for a spin after every swap. It turned out to be the driver's side rear wheel/tyre.

Just saying: Don't go buying parts untill you've eliminated the 'easy' things.

[abs66]

I also had a bad vibration problem and wheel balancing made little difference.

I too used the spare method and mine turned out to be offside front tyre causing the problem. Swapped out and all good now.

Its a pain to check if it turns out to be the last one checked but cheap to try.

Also check if one wheel is hotter than the other just after a run in case you have a sticky caliper, sounds odd I know but experienced similar vibration on an old Mazda xedos 9 I had.

Good luck with your diagnosis.

[ambermarine]

at speed (85+ - for overtaking, maybe) im getting a violent shake throughout the car.

having had the wheels balanced there is little wobble in the steering wheel, it is felt through my feet on the floor, but is violent enough to feel it though the whole seat and make it impossible to drive at that speed, as its so uncomfortable but equally as im anxious the car is about tear apart.

it isn't accompanied by any unusual noises.

i had a full service within the last couple months and the VSR mentioned nothing suspension related, with the wheels discounted does anyone have any suggestions what the problem might be or tips to narrow it down

Regard

Oliver

It sounds like the suspension bushings on either the trailing arms, hub knuckle or both the way to check is take all the weight off the suspension by jacking up the car and supporting on stands under the subframe to body mountings.

If the wheel will move in and out accross the 3 to 9 axis the hub knuckle bush is suspect as is the hub side trailing arm mounting but that mounting will also move up and down if worn .if these two bushes are worn it accentuates the vibration problem. when we had this vibration problem we suspected the prop shaft but it was sound and I think yours probably is.

If your car as done in excess of a 100K the bushes are in the frame.Check out the LS400 rear suspension bushing replacement topic and pictorial in the workshop tips ,we did this work and the car now runs perfect.

[Bluesman]

Its a pain to check if it turns out to be the last one checked but cheap to try.

Hi Pete

But in my world its always the last one you checked, so do you know another method where if its the 1st one you try it wont be the last one you tried.

Mike

[abs66]

Haha

I wish Mike I wish. I must live in the same world as its always the last thing checked that's the culprit. Having said that I tend to learn a decent amount of stuff along the way :-)

With regards to alternative methods I've tried the old switcheroo and its always been obvious that had I started where I originally proposed to I would have found the problem straight away........or would I !!!

[John N]

Don't assume that because you've had the wheels balanced that they are OK.

I've had tyres that have gone 'out of round' and have had bulges, but on the wheel balancing machine they have balanced up OK. jack up each wheel, spin it and watch it go round very carefully and look for any sign of it being out of shape.

I've also had the experience of having new tyres fitted and balanced, only to find I had a similar vibration. Went back to the tyre fitter and had them check the balancing again, but there was no improvement. I then took the car to a different garage that I trust and put the wheels on their balancing machine, according to their machine they were all 'out of balance'. When they had put them right the car was as smooth as silk! (I even managed to get the tyre supplier to pay for the re-balancing.)

John N

[Bluesman]

Don't assume that because you've had the wheels balanced that they are OK. I've had tyres that have gone 'out of round' and have had bulges, but on the wheel balancing machine they have balanced up OK. Jack up each wheel, spin it and watch it go round very carefully and look for any sign of it being out of shape. I've also had the experience of having new tyres fitted and balanced, only to find I had a similar vibration. Went back to the tyre fitter and had them check the balancing again, but there was no improvement. I then took the car to a different garage that I trust and put the wheels on their balancing machine, according to their machine they were all 'out of balance'. When they had put them right the car was as smooth as silk! (I even managed to get the tyre supplier to pay for the re-balancing.) John N

Why are there so many cowboys around just waiting to inflict as much GBH on not just our cars but our wallets as well.

My recent brush with Micheldever tyres who charged me £30 just to make the problem I had even worse despite me asking them to put it onto their computerised 4 wheel alignment machine, they insisted that the normal wheel alignment was all it needed oh yes and £250 of new tyres. Elite Tyres in Reading after finishing the 4 wheel alignment job said it was along way out, I wonder why?

Good luck with finding the problem.

Mike

[abs66]

Maybe we should do our own list of trusted competent suppliers/fitters etc for each area.

That way we would be more confident of getting a decent honest job done and the good garages would get extra business. Happy days all round.

[oliver261]

hello all,

thanks for the replies. looks like this could be big/expensive if i dont do the work myself.

ill start working my way through the possibles over the coming weeks. i may have been a bit hasty discounting the wheel balance, due to new tyres. particularly as ive not used the fella before.

the car is well past 100k at 162 (i was hoping that it might hold out until the other side of 200). knew that suspension would be a prime candidate but thought it would have been picked up in the VSR

to anyone who has had prop shaft issues, is there any tell tale signs or play in it on inspection, or is it a case of changing it once other things have been ruled out and seeing if it goes away?

cheers

oliver

[Malc]

This seems a ridiculously low mileage to have any sort of propshaft problem ................... well, on a Mk1=2=3 anyway !

Just my thoughts.

Malc

[wollo]

Malc, I've not long bought a mk4, couldn't help but notice you've left that one out, any reason I should know of as I've a bit of a high speed shake I'm just starting to chase down now.

Bill.

[Malc]

Only reason I left out the Mk4 was because I've not yet had one ..... but in my 3 x LS400s over these past 10 years I KNOW that they wouldn't have a propshaft issue ......... maybe I'm lucky but I don't think so, the build qualioty was too good ! My MK1 had covered 190k.

Malc

[oliver261]

Had to do a long moorway run last night. Don't know whether the prob is getting worse or I'm concentrating on feeling it. Was getting a light vibration from 80. Again not through wheel.it's very inconsistent and seemed to vary with road surface. So am I right in leaning toward suspension and more likely rear end

Not got chance to have a poke round yet so just thinking stuff through. Would I be right in thinking the if it was prop shaft it would rev dependent rather than speed. So I'd get the vibration at 2600rpm through all the gears. Could this be way to narrow it down

[Ruud]

Had to do a long moorway run last night. Don't know whether the prob is getting worse or I'm concentrating on feeling it. Was getting a light vibration from 80. Again not through wheel.it's very inconsistent and seemed to vary with road surface. So am I right in leaning toward suspension and more likely rear end

Not got chance to have a poke round yet so just thinking stuff through. Would I be right in thinking the if it was prop shaft it would rev dependent rather than speed. So I'd get the vibration at 2600rpm through all the gears. Could this be way to narrow it down

As a few have said (incl me) start with the wheel swapperoo....cost you nothing but some energy. As soon as that is eliminated, put in on a ramp somewehere and inspect suspension points for play.

[Bluesman]

Had to do a long moorway run last night. Don't know whether the prob is getting worse or I'm concentrating on feeling it. Was getting a light vibration from 80. Again not through wheel.it's very inconsistent and seemed to vary with road surface. So am I right in leaning toward suspension and more likely rear end

Not got chance to have a poke round yet so just thinking stuff through. Would I be right in thinking the if it was prop shaft it would rev dependent rather than speed. So I'd get the vibration at 2600rpm through all the gears. Could this be way to narrow it down

I would check your rear tyres.

You say it changes with the road surface, If it was the prop the road surface wouldn't make any difference.

Mike

[Parrot of Doom]

Definitely do the simple things first. Warped or damaged tyres are easily missed by a balancing machine, which will do its job iwthout the weight of the vehicle on the tyre.

Get a pry bar into that rear suspension and check the bushings. I think my trailing arm bushings are on the way out and truth be told I have a slight "mmmmmm" at 60-65mph that definitely isn't tyre related. I also have a minor wobble over 90ish but nothing uncomfortable yet.

[mr2lad]

As I said earlier...I went thru all of the above ie wheels balanced new suspension, new discs even new wheels tyres but shake was still there put up with it but now getting worse ie shaking on steering wheel and thru the seat ......if you leave it, it will get worse I now feel it at 50mph swapped and renewed everything but to no avail so just the centre prop bearing can be the problem now.....

[Parrot of Doom]

Most wheel balancing machines do so with the wheel off the car - which means that the weight of the car is not pressing down on the tyre while it is balanced.

That's fine for a good tyre, but if you have a tyre with a minor sidewall weakness or a slight warp, faults that only make themselves known when a third of a tonne of weight is pressing down on them, it won't get detected.

Google "road force balancing" for more info.

[mikeyv]

Jury is still out then?

Regarding the prop vibrating at certain revs, it won't vibrate for long in the lower gears, as the box will shift up, you'll only get prolonged periods at constant revs when cruising.

However, the mention of road surface would be more likely to steer me away from the shaft, probably towards suspension.

Hope you get it sorted soon, and please put us out of our misery when you do.

[John N]

Had to do a long moorway run last night. Don't know whether the prob is getting worse or I'm concentrating on feeling it. Was getting a light vibration from 80. Again not through wheel.it's very inconsistent and seemed to vary with road surface. So am I right in leaning toward suspension and more likely rear end

Not got chance to have a poke round yet so just thinking stuff through. Would I be right in thinking the if it was prop shaft it would rev dependent rather than speed. So I'd get the vibration at 2600rpm through all the gears. Could this be way to narrow it down

No, you'd be wrong! The prop shaft is connected solidly to the back wheels through the differential. According to the spec the dif ratio is 3.266 to 1 which means the prop shaft turns 3.266 times faster than the back wheels.

John N