Wheel Shudder between 80-90mph

[tonyg1987]

Whilst driving between 80-90mph on a private road, I get vibration/wheel shudder at the front wheels. Anyone experienced this before? it is only noticeable between these speeds. The car drives normal otherwise. the car was recently serviced and has 4mm at the front and 6mm at the rear. brake wear is around 40% with plenty left. the car has different make of tyres on the front and on the back. car has 19" and has the standard oem tyre sizes on both front and rears.

does it require balancing? or alignment?

thanks

 

[adamgillett]

I had this happen to me. First thing is to get the wheel balance checked. Mine was way off!

 

[ecain63]

My rear left wobbled / shook above 100mph. Took it to the tyre shop and they said the wheels were in balance according to the machine. But, on closer inspection whoever had balanced them previously had counterbalanced, instead of properly balancing. That's fine for normal road use but C63's are designed to go quicker from time to time. A rebalance sorted my problem.

Counterbalancing will cause your wheels to distort at speed, which is where the wobble comes from.

 

[StuartK]

Does this only happen on a private road?

 

[merc85]

Does this only happen on a private road?

Depends on the quality of the Private road lol

 

[tonyg1987]

Does this only happen on a private road?

thanks gents, i'll take it to my local to get looked at as i doubt MB would cover this on warranty.

the condition of private roads in the UK are appalling

 

[RJ C63]

Yep wheel balancing had this on mine too.

 

[st13phil]

Counterbalancing will cause your wheels to distort at speed, which is where the wobble comes from.

Pardon?

 

[ecain63]

??^^

 

[st13phil]

??^^

You said in your earlier post "...had balanced them previously had counterbalanced, instead of properly balancing" (my emphasis).

Also, "cause your wheels to distort at speed"

I was trying to understand what you meant?

 

[ecain63]

Sorry.

Correct balancing involves adding weight to an area of wheel where the weight is not as per the rest of the unit. This to try to even up the rotating mass of the wheel and tyre. An evenly weighted wheel will spin smoothly at high speed.

Counterbalancing is this:

Say the wheel is 10g out of balance. You SHOULD add 10g to the area lacking the weight and check balance. Job done. In the case of my wheel the fitter had fitted 20g to the area lacking weight and 10g directly opposite. Technically the wheel will be balanced at road speed. However! As speed increases above normal road speeds the weights suffer the increasing effects of inertia and force the wheel into a slight oval. This causes the wheel to bounce on the road like you had eggs for wheels.

It sounds daft that people would do it but my tyre guy says he sees it all the time. He took the theoretical 20g and 10g weight off and refitted a new 10g where needed. No issues at all now.

 

[fabes]

When I had this, it was down to a wheel weight having come off (sticky / dirty patch still there)

Easy rebalance by the garage

 

[Red C220]

Why would someone counter balance a wheel in that way, it seems more work for a less agreeable solution?

Is there some advantage to this practice?

 

[E55BOF]

Laziness? That aside, I'm afraid I don't believe for one moment that the wheels on C63s, or indeed on any AMG (which are also designed to go faster from time to time than in "normal road use" in the UK - perhaps your tyre guy thinks different wheels are fitted in Germany?) are so lacking in stiffness that they would distort with a 10-20g imbalance. I think your tyre guy needs a reality check...

 

[StuartK]

Laziness? That aside, I'm afraid I don't believe for one moment that the wheels on C63s, or indeed on any AMG (which are also designed to go faster from time to time than in "normal road use" in the UK - perhaps your tyre guy thinks different wheels are fitted in Germany?) are so lacking in stiffness that they would distort with a 10-20g imbalance. I think your tyre guy needs a reality check...

This.

 

[tonyg1987]

found out the reason why the wheels were vibrating the inner sidewall was shredded!!

 

[Bewva]

That'l be down to them 'private roads' again.

 

[tonyg1987]

not sure but last service last month MB said tyres were good! 4mm left. however inner sidewall is splitting from the braids. surprised i didnt end up in a ditch tbh

 

[AMGeed]

That shows MB only gave the tyres a cursory look and took no notice when it was on the ramps.
I have to own up to thinking my fronts had loads of tread until I parked up on full lock and was surprised to see a threadbare bald strip around the inside edge.

 

[st13phil]

There's a reason why it's considered good practice to check your tyres - tread, and both sidewalls - at least every month, and certainly before any high speed travels...