vibration at 110kph - 120 kph

RobAMerc

lads
friend bought a car from a dealer which when he got on to the motorway had a vibration between 110 -> 120.
He brought it back and the dealer re- balanced the wheels but the same still seems to be happening

what else do you think could be causing this other than wheel balancing ?

something bent in the suspension ? drive shaft bent ? or a buckled wheel ( which I presume would mean the wheel could not be balanced.

blackbox

Did dealer balance all 4 wheels? Some people seem to think that only the front wheels need to be balanced.

RobAMerc

yes - all four done

comes through the steering wheel, but can feel it though the seats too.

corkgsxr

Some don't service there machines. They'll never get it right if not.

JerCotter7

What kind of car is it?

blackbox

Buckled wheel is possible, but more likely to be a damaged or faulty tyre. A bent shaft is pretty unlikely.

Worn shocks could also cause vibration, but easy to check by bouncing the corners.

RobAMerc

blackbox wrote: »

Buckled wheel is possible, but more likely to be a damaged or faulty tyre. A bent shaft is pretty unlikely.

Worn shocks could also cause vibration, but easy to check by bouncing the corners.

Actually the garage claimed the tyres on it were faulty originally as the car had been sitting around the showroom for a while - they flat spotted
All four were replaced and balanced - but there is still a vibration

Matt Simis

What car?

Could be wrong wheel bore to car hub (ie E39 wheels on E46), fixed with spigot rings.

Other possible candidates are low gearbox oil or low diff oil.

Ronnie Beck

RobAMerc wrote: »

Actually the garage claimed the tyres on it were faulty originally as the car had been sitting around the showroom for a while - they flat spotted
All four were replaced and balanced - but there is still a vibration

Maybe I'm been cynical but it sounds like there stalling. Maybe a gear box problem. Try the same speed in fourth or press in the clutch.

mullingar

These are the usual suspects when balancing wheels:

Balance to just 5 grams on all 4 wheels (watch the tyre fitter doing this)
Check the run-out on the wheels (making sure they are not egg shaped)
Sh1te tyres (this did happen to me!)
Swap wheels front->rear to isolate faulty wheel/tyre
Borrow 4 other wheels, if no more vibrations, buy new tyres AND wheels

Failing these 5 steps, its going to be an expensive repair

jd6920s

Get the torque converter checked out

RobAMerc

mullingar wrote: »

These are the usual suspects when balancing wheels:

Balance to just 5 grams on all 4 wheels (watch the tyre fitter doing this) - will do
Check the run-out on the wheels (making sure they are not egg shaped)They put new tyres on it - I suspect a buckled wheel
Sh1te tyres (this did happen to me!) - They are not sh!te tyres in fairness
Swap wheels front->rear to isolate faulty wheel/tyre Diff sizes - so hard to do
Borrow 4 other wheels, if no more vibrations, buy new tyres AND wheels
I am going to run the spare in a few different positions and see where we are at

Failing these 5 steps, its going to be an expensive repair

But what ?

jd6920s wrote: »

Get the torque converter checked out

wouldn't that be juddering while accelerating ? and slipping revs rather than a vibration at certain speeds ?
I presume changing gear ( engine speed would rule this out )

thanks all

mullingar

To check for tyre run-out or a buckled wheel, get a electronic dial indicator complete with an magnetic arm Example.

Measure for any egg shape as you spin the wheels when mounted on the car, no more than 1mm tolerance. You can also use this tool to check for minor buckles.

If you have a buckle, there are a few alloy wheel repair companies.

Suasdaguna1

Pal of mine had 2 classes from 03/04 era.....both had similar issues......both required drive shaft repairs. V v expensive.

Head wrecker ....

Matt Simis

Suasdaguna1 wrote: »

Pal of mine had 2 classes from 03/04 era.....both had similar issues......both required drive shaft repairs. V v expensive.

Head wrecker ....

How would it be expensive? Surely its just a matter of sourcing a known good driveshaft and fitting it. Obviously buying a new one would be OTT expensive, but who would do that?

Balancing a driveshaft is not overly difficult either, just requires a workshop with a long balancing machine.

Suasdaguna1

Matt....you'd be surprised how many garages turn away that type of work and settle on oil/filters as their ply of trade.

Expensive as a main dealer was involved and yes they farmed out the job.

Back to Op orig post.....if its a rear wheel drive, drive shaft is definitely worth a gander.

shamwari

I've experienced problems on FWD cars like this which was caused by a defective inner CV joints, and in one extreme case, a defective DIFF.

***Edit: on a rear wheel drive, both sections of the centre drive shaft are usually balanced. If the shaft was seperated in the middle(e.g. hardy splicer repair) and both sections are not matched back up as they were before then the whole shaft could be out of balance and therefore create vibration.

joujoujou

Out of shape brake discs may also be a source of vibration. Even while not breaking.

Supergurrier

Sounds like a Buckled alloy, bring it in and spend 20 quid getting it balanced elsewhere and they will tell you if it has a buckle