Rear wheel angle

[BMWhatever]

I recently have gotten some unbalance in my car. I can feel that it comes from the real wheels. It's not the front wheels otherwise you would have felt it in the steering wheel right away.

I went to a tyre workshop and told them to balance the rear wheels. They couldn't find any unbalance in the rear wheels at all.

The problem remains and I've checked the brakes that they are not pressing on the disc.

This makes me question the angle of the rear wheels. On my car the rear wheels have a heavy toe out, very obvious one. Although I've also noticed that on many BMWs have a heavy toe out on the real wheels. It seems like a BMW thing to have.

My questions are:

Is it normal to have very much toe out on my BMW? It's obvious that the wear on the tyres are almost on the inner section.

Can too much toe out damage the tyre? For example the threads can't handle too much pressure on one side only.

Is there a way to adjust the wheel angle?

Why has BMW chosen to have very much toe out?

[sp0rky]

Toe in or out KILLS tires, but BMW never designed a car with "heavy toe out" or any toe out at all.

Perhaps your mistaking the toe for the Camber.
There is a good deal of Negative camber which makes the wheel look like its in toward the middle of the car toward the top, and out more from the car at the bottom.

BMWs generally have a mild degree of toe in, meaning that the back of the wheel is out from the car a little and the front is in toward the middle of the car. Toe out would be opposite.

The combination that they have chosen is a huge compromise between the best handling they can give, quiet ride and tire life. Because it is still a "luxury sedan", it needs to still give acceptable tire wear andbe fairly quiet.

Toe in / Negative camber wont cause a shimmy unless they are uneven on each side.

a shimmy/ shake / vibration coming fromt he rear of the car could very well be an overlooked drivetrain issue such as an unbalanced driveshaft, etc.

[BMWhatever]

I think I mixed up the word "toe out" with the front wheel adjustment. What I tried to describe was that the lower part of the wheel is points more outside the body than the upper half. So eccentially the tyres run more on the inner half.

Looking from the rear of the car the wheels are tilted so that upper half of the tires are closer to the center of the car than the lower part. Probably the word you mentioned as camber.

So my question probably regards about the camber. Thanks for correcting me.

So this "camber" angle, does it kill my tyres?

[sp0rky]

I tried to go into detail, but I think I went off track on the last post...

BMW used this to make for better handling, but it has to be a compromise between tire wear, noise and handling - SO YES, it does kill your tires more so than another car would. Also - reading the owners handbook of your car statest that they do not recommend rotating the tires, so you are essentially waisting the outter half of your tire as it will be hardly worn when it is time for new tires. Let me go snap a pic of my e39.

[sp0rky]

Unfortunately that is a normal wear pattern of a car with a lot of neg. camber. Of course this car has the sport package, so I believe the neg. camber is a little more than normal, but still - same wear pattern.

[mdimbler]

BMWhatever - as sp0rky mentioned, it could be a drivetrain issue. It could also be your rear ball joints.

[CosmosBlack]

The rear (as well as the front but not as much) negative camber
is something E39 owners like myself have to learn to live with.
Especially if you have a lower sports package.

I DO rotate my tires...however...due to the directional tires, and staggered tire sizes, I cannot rotate them as you normally would.
What I have to do is flip the tires and remount them on the same wheels.
You gotta think about it a little to understand,
but I'd recommend that as it saves you your tires, which otherwise would have been wasted.

[BMWhatever]

Can the camber destroy the threads of the tyre and make it unbalanced that way? My previous tyres became unbalanced, they were regumated though so it could be a quality issue as well.

My manual recommend rotating tyres. Only back<->front because of directional tyres.

The drive train, what do you recommend that I look over there?

[sp0rky]

I really don't think it would de-balance the tire to the point that it would vibrate like your explaining.

There are many issues of the drivetrain to check over, but since yours is an e34, first things on my list would be: Tranny mounts, Guibo, Driveshaft center bearing and u-joints.

Good luck, hope you get it all sorted out.

[EXtech]

as mentioned earlier, look over the rear end well. Ball joints on these cars wear out and eventually throw the rear alignment out of whack and also create vibration. The other common issue are the wheel bearings. Put the car on a lift and grab a rear wheel/tire at the 3 and 9 o'clock position and try to wiggle it back and forth. See if there is any play. Generally this works if the bearing is worn a great deal. If it's not that bad yet, you won't notice it with this test. Other than that, look over all of the rear bushings (especially the control arms) and the ball joints. Good Luck!!

[BMWhatever]

Thanks, I know there is no play in the real wheel but I will definetly check the drive train. BTW as I'm not a native English speaker, what is "guibo" and "u-joints"

[sp0rky]

the guibo is what BMW calls the little flexible coupling that connects the driveshaft to the output shaft of the transmission.

the u-joints are "universal joints" that connect the two driveshaft halves together to allow movement in both directions.

[EXtech]

keep in mind though.. even if you have no visual play in the wheel.. a bearing can still be bad enough to cause a noise or vibration

[CosmosBlack]

Hey ExTech! Good to see you're still here after all this while!
Thought I haven't seen you in a while.

[EXtech]

hey cosmo.. thanks for the hello... good to see your 'face' too. I've been away a while but back to my roots ; )