[Gus]

Hello all. I just finished getting a new set of Yokohama AVS Sport (235/45 & 255/40) along with an alignment (only thing you can do to the M Coupe is front toe adjustment...) For some weird reason or another, now the car pulls to the right. We are talking 3-4 seconds (doing 55mph) to go from the center of a lane, to the right edge!:yikes:

The old Dunlops tracked straight as an arrow. They were loud (compared to the Yokos), but that may have something to do with the fact that the inside passenger rear tire was down to the threads! (something I only saw when the tires were taken off, otherwise I would have replaced them a lot sooner). Seems like a common issue with these cars

Only thing changed in the alignment was the front toe (originally was at a total of 46'!) and now it is set at 24' total (12' on each side). No wonder the outside shoulders of my front tires were gone, while the rest of the tire was fine. The rims were all statically balanced (fronts used .50 each and rears was 1.25 on one and 1.5 on the other).

Any ideas? Suggestions? Reccomendations? Thanks in advance to all who reply.

Gus:banghead:

 

[Gus]

Alignment results

Here are the remaining specs after the alignment:

FRONT:
Caster left 6º18'
Caster right 6º48'
Camber left -1º12'
Camber right -0º30'
Toe left 0º12'
Toe right 0º12'

REAR:
Camber left -0º42'
Camber right -0º42'
Toe left 0º27'
Toe right 0º39'

I know the front caster and rear toe are way off specs. Anything to do (besides replacing control arms). :dunno:

 

[dr z]

hunter balancer

on an e-mail forum for mercedes ml, the issue of tire balancing has been the topic of much discussion over the past few years. the general feeling of that group is to go to an installer who has a top-of-the-line hunter balancer (i can't remember the the exact model). many bmw, mercedes and similar dealers have these hunter balancers and the ml owners who have taken their problematic tires to these dealers (whether or not they bought the tires there) have usually had the problem solved (if in fact it was related to the balance and some lesser balancer didn't catch it. of course, your situation may be a whole other problem.

dr z

 

[rost12]

This GSP9700 is the alignment thingy that dr z is talking about. They have a list of their locations up on the site.

Not sure if it will help you, but from what I gather this is the best alignment machine there is. (I've gathered that mostly from E39 forum at roadfly.org)

 

[Gus]

Thanks

Thanks DrZ and Rost12. Unfortunately for me, here in Panama I am stuck with what there is. The tire balancing machine used for my wheels was the Coats 950 and the alignment machine was teh John Bean Visual Liner (or Linear?) Series. Apparently this is what most of the tire shops in town use. I will try some other strech of roads late tonight to see if it does the same, or if it was just the road I was in (I doubt it as I drove on both lanes to and from my house with the same effect :thumbdwn: )

In any case, thanks for the replies :thumbup:

 

[Pinecone]

Re: Alignment results

Here are the remaining specs after the alignment:

FRONT:
Caster left 6º18'
Caster right 6º48'
Camber left -1º12'
Camber right -0º30'
Toe left 0º12'
Toe right 0º12'

REAR:
Camber left -0º42'
Camber right -0º42'
Toe left 0º27'
Toe right 0º39'

I know the front caster and rear toe are way off specs. Anything to do (besides replacing control arms). :dunno:

I would say it is due to the camber difference between the left and right front. Camber generates thrust (see how a motorcycle turns) so the extra camber in the left front generates more thrust than the right font, leading to a movement to the right.

There are camber bolts available from BMW dealers to allow up to about 1/2 degree camber adjustment.

Or, if you don't compete and have to deal with rules and classes, you might consider a set of camber adjustment plates, like the Kmac. They are available form people like Bavarian Autosports, BMP, Turner Motorosports, etc.

 

[bmw325]

Also possible that the dealer's alignment rack wasn't properly calibrated--and the toe is actually uneven from side to side. I had to take my car (325i) to several dealers to get a proper alignment. Another possibility is that tey didn't do a "thrust angle" alignment which basically reads the rear toe angles and allows them to adjust the fronts to compensate. I'd be very surprised of the rear toe can't be adjusted too.

Camber differences will causes the car too pull to the side w/ the less negative camber-- this could also be part of the problem-- however most cars are set up w/ slightly more negative camber on the right side to compensate for road crown.

 

[Pinecone]

Also possible that the dealer's alignment rack wasn't properly calibrated--and the toe is actually uneven from side to side. I had to take my car (325i) to several dealers to get a proper alignment. Another possibility is that tey didn't do a "thrust angle" alignment which basically reads the rear toe angles and allows them to adjust the fronts to compensate. I'd be very surprised of the rear toe can't be adjusted too.

Camber differences will causes the car too pull to the side w/ the less negative camber-- this could also be part of the problem-- however most cars are set up w/ slightly more negative camber on the right side to compensate for road crown.

Differences in toe from side to side will not effect hands off stability, only when you try to hold the steering wheel "straight".

Thrust angle alignment can be a very good thing.

AFAIK the rear toe is not adjustable stock.

Intentional camber differences assume a crowned road, and only a two lane road. It could very well work against you on a freeway or single lane road.

 

[bmw325]

The rear toe is definitely adjustable. i've read the procedures for it on the ETK-- requires a special tool but pretty straighforward. In fact, camber and toe can be adjusted w/o the use of any shims at all 4 corners on the E46. Agree that uneven toe shouldn't cause stability issues-- just steering wheel that's not straight--although a toe out condition could cause instability.

 

[Gus]

E46 or E36/8 that is adjustable

robg, I do not know well the E46 cars, but the dealer even got me a copy of the ETK where it stated that the rear could not be adjusted in my car (E36/8 M Coupe). The steering wheel is straight in my car. The pull only shows up if I let go of the steering wheel (which stays straight as the car veers off to the right).

Rear thrust measured out to -0º06'

Oh well, I am just going to drive it that way and enjoy the hell out of it :lmao:

 

[AF]

One thing about getting new tires is to never judge the way your car is driving until you break-in the new tires.

New tires always feel strange because they are not worn into your car yet. I'd wait until 500 to 1000 miles and I am sure your car will feel better then.

Can there be an alignment problem now ? ? Yes but you should let the tires break in first !!

 

[bob lindquist]

tracking

toe in and out plays major factor on tracking. It s track straight on highway or tighter handling on turns pick one