Extreme Vibration at 45 plus MPH

maseratimike7

Junior Member
Messages
178
Hi Guys,

Have a new issue with the GS, out of no where the car shakes violently above 45 MPH, never had this issue with the car before.

All tyres are new balanced and it has had a full hunter alignment. I have checked the following so far, Tyres, wheels are tight, wheel bearings, calipers for sticking, driveshafts, CV joints, TR ends, wishbones and bushes and all seem to be solid and in order.

Has anyone else experienced this and could advise what else I should check or what it possibly could be?

It’s as if I am driving on square wheels and the car is basically unusable in its current state.

The vibration is felt through the steering wheel and seat of the pants without any changes made during acceleration, braking, putting the car into N and coasting etc

Thanks for the help in advance!

Mike




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CatmanV2

Member
Messages
28,858
Does it do it standing still? I'm guessing not?

If so, I *think* is has to be something after the gearbox but that's probably not that much help :(

C
 

Forcerouge

New Member
Messages
12
You say that the tyres are new and balanced, but are you sure they still are?
Maybe one of the balancing weight got off?
 

2b1ask1

Centenary Club
Messages
14,469
A long shot but a significant amount or water in one or more tyre? Is it very consistent?
 

Oneball

Member
Messages
1,261
Jack the back up, put it on axle stands and run it up to 45.

That way you’ll know if it’s front end or rear/drivetrain.

You may get an ABS/TC light but you can reset that later.
 

FIFTY

Member
Messages
1,509
I had this problem after a new set of front tyres... They didnt balance them properly and were 100g out on one side!
 

Felonious Crud

Centenary Club
Messages
12,046
You say that the tyres are new and balanced, but are you sure they still are?
Maybe one of the balancing weight got off?
If it started suddenly, this would get my vote. Happened to me last year. It's also the cheapest fix! Fingers crossed.
 

maseratimike7

Junior Member
Messages
178
Does it do it standing still? I'm guessing not?

If so, I *think* is has to be something after the gearbox but that's probably not that much help :(

C
No it’s fine and smooth up to 45 mph and then it kicks off!


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maseratimike7

Junior Member
Messages
178
I had this problem after a new set of front tyres... They didnt balance them properly and were 100g out on one side!
I have been driving the car for a week on the new tyres and it was fine. All the weights are still in position, is it possible for them to unbalance after a period of driving?


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maseratimike7

Junior Member
Messages
178
Jack the back up, put it on axle stands and run it up to 45.

That way you’ll know if it’s front end or rear/drivetrain.

You may get an ABS/TC light but you can reset that later.
Wouldn’t have thought to try this but I’ll give it a shot, thanks.


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FIFTY

Member
Messages
1,509
I have been driving the car for a week on the new tyres and it was fine. All the weights are still in position, is it possible for them to unbalance after a period of driving?


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If you took the car up to 70mph+ and back down again with no vibrations after getting the tyres done and all weights are still in place it may well not be that... but it's a good place to start

Have you driven over any rough roads? It is very easy to pick up buckles on the inner face of the rim this time of year, the 19's on the GS are particularly bad for it although I have discovered a buckled rim on my multispoke 18's and another forumer reported similar a few months ago... you can try to check for them visually but a garage would typically use the balancing machine to check for them :)
 

maseratimike7

Junior Member
Messages
178
If you took the car up to 70mph+ and back down again with no vibrations after getting the tyres done and all weights are still in place it may well not be that... but it's a good place to start

Have you driven over any rough roads? It is very easy to pick up buckles on the inner face of the rim this time of year, the 19's on the GS are particularly bad for it although I have discovered a buckled rim on my multispoke 18's and another forumer reported similar a few months ago... you can try to check for them visually but a garage would typically use the balancing machine to check for them :)
I always take it to the same garage and when they first fit new tyres they advised that the rims were slightly out. I have read on the forum as you mentioned that the 19 are suspect for this especially on the UK roads.

I haven’t driven on any different type of roads and the wheels have never caused any noticeable issues or look to have sustained any damage since the last tyres were fitted.

Seems like its going to be one for a lot of investigation to find the problem by trial and error.

I am two hours from my nearest Indy or main dealer which makes things slightly tricky.


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CatmanV2

Member
Messages
28,858
Local garage with a 4 post. Get it 6 inches off the ground and bob's your uncle. It'll at least give you and idea.

C
 

outrun

Centenary Club
Messages
3,829
I'd guess at wheel damage as well. As others have said, first place to start is have the wheels rebalanced as that's cheap and it could well identify the issue.
 

Contigo

Centenary Club
Messages
17,459
Flat spots on the tyres is my educated guess. Had it before and it happens on cars which have sat for a long time. This is why it is recommended to over inflate the tyres prior to hibernation etc...

If the tyres are indeed brand new then get them rebalanced as something has gone wrong, weights fallen off? At the wrong place on the wheel etc.... Failing that a wheel has been buckled perhaps.
 

conaero

Forum Owner
Messages
29,041
I wouldnt drive it.

Get it all checked out. The upper front wishbone bushes are the weak points on them.
 

Zep

Moderator
Messages
2,424
I agree with Matt. The upper rears can also fail. A thorough inspection is the first thing to do.