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MG MGF Technical - bad vibes
|My MGF has a vibration through the steering wheel and body at between 50-60 MPH, I have had the wheels balanced a couple of times and had the wheel alignment checked but the problem still exists.|
Has anyone else had similar problems????
and if so what could be the cause??
|If you've had your wheels balenced then it could be a number of things.|
Play in the steering rack, worn ball joints etc.
Get the front of the car off the ground and move the wheel around all directions with some force and ask someone to look at the suspension mount and pivot points to see if there is any excess movement and or suspicious noises!
|Wheel balance and tracking would be my first ports of call as well - so if these are okay, then the problem points to the tyres themselves.|
I wonder if the tyres have been flat-spotted? Might also be a manufacturing fault, if the wheel is slightly out of true. I seem to recall Roger Parker talking about these issues some while ago - have a search in the archives for more info Stu.
One way to check this is to either swap the wheels front to rear (assuming that you have the same profiles all round) or to switch each wheel in turn with the spare. If driving on the spare the vibration goes, then you've found the offending wheel/tyre.
If the problem isn't with the wheel or tyre, then suspect the suspension as Rich has rightly highlighted.
|the last time I had the wheels balanced a couple of weeks ago the guy found that one of the wheels was badly out of balance and suspected that the wheel might be buckled, he removed and refitted the tyre which made it better and he was able to balance the wheel correctly.|
Not of the wheels have been kerbed badly so I can only assume that the problems lies with the suspension
|Oh just thought of something else!|
A few years ago I did some work experience at a brake company. All the work was carried out on Dyno's but there was a signifciant interest in something called Disc Thickness Variation (DTV). This is where as the name suggests the disc goes out of flat, usually caused by alot of motorway driving where the pads are rubbing against the disc but only at a very light pressure. It used to show it on the car in a vibration coming thru the wheel at higher speed with the brake off! I don't know if you have access to a micrometer but we used to measure the disc at 24 points around and it showed up like a wave.
Or change the brake discs for new ones.
|I've also had problems with vibration at a specific speed, got the wheels balanced with no improvement.|
Just to say, i am a bit wary of some people that "balance wheels".
I was informed that their machine was only accurate upto speed of 70 mph. which was of no use to me as the vibration was occuring at 90 mph.
Would advise looking at tyres closely, I checked mine recently, tread, presures all ok. Wasn't until i removed the wheel that i noticed, one of the side walls had "ballooned out" and had a huge bulge in the sidewall.
I replaced the two rear tyres, and then got the wheels balanced, but although problem got marginally better it was still there.
Dealer tried to sell me a new set of alloys, saying one or two of my wheels were buckled.
Fortunately, i clouted a nasty pot hole (plenty of them in Glasgow) and knocked the balancing weight off.
Anyway, seems to have fixed the problem, vibration totally gone now.
|cheers for the advice all, your are the second person Richard that has mentioned brake discs to me so I'll try and check for warping or thickness variations as soon as I get chance|
This thread was discussed on 14/03/2003
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