PDA

View Full Version : Help needed with e39 M5 Wheel Alignment



TimInNOVA
02-22-2010, 11:59 AM
I took my 2001 M5 (79,800 miles on it) to a local tire store to get the wheel alignment checked and I have a few questions post-results.

Prior to this the car went down the road true and straight, but the outer-edge of both front tires are showing considerable wear. Back in August I replaced the thrust-arm bushings due to steering wheel shimmy over 40MPH, and that solved that problem. I thought the wearing on the outer-edges might have been caused by the worn thrust-arm bushings (that is one of the symptoms as I understand it), but I thought it could also be caused by a bad case of toe-in.

I've attached a copy of the alignment print out.

1st question: What would cause my right-front wheel's caster to be out of spec? A worn bushing or possibly a bent strut? I know caster is not adjustable, but I figure a good mechanic might be able to move the strut or something to help this out.

2nd question: My rear toe looks very out of spec and I want to get this and the front caster adjusted, but I want to take it to someone that really understands BMW e39's. Can anyone recommend a non-dealer BMW alignment guru in the NOVA area?

Thanks,
Tim

mcoupemindy
02-22-2010, 02:03 PM
Where in NoVA are you?

Nick325xiT 5spd
02-22-2010, 02:46 PM
The shop looks like it did a shit job aligning your car. Either something is wrong in the rear suspension, or they just couldn't be bothered. As for the front caster, .3 degrees out is nothing. It probably came that way from the factory. The only thing you can do to mess with it is a) replace the kingpin (probably won't help), b) move the shock tower with a frame twisting machine (dumb), or c) buy adjustable camber/caster plates. The last option would fix it, but honestly, don't bother.

RRT should understand alignments.

Curry's does a good, albeit insanely overpriced alignment.

Excluservice does a good one.

TimInNOVA
02-22-2010, 02:48 PM
I live in McLean, near Tysons Corner.

TimInNOVA
02-22-2010, 02:57 PM
Thanks Nick. I'll try RRT.

mcoupemindy
02-22-2010, 03:59 PM
Thanks Nick. I'll try RRT.

Definitely go to RRT and never look back.

glindsay
02-22-2010, 08:31 PM
We have had our ’02 M5 since new and it now has 74,800 on it. It’s my wife’s daily driver and has a short commute. As far as she’s concerned, there’s only one seat in the car and it’s her's. She has had it on the track a dozen schools. I normally track our E36’s and E46’s but have had the M5 on out on the track some too. We run PS 2’s on the stock wheels on the street, Dunlop M3’s in the winter on 540 stock wheels and PS Cups on D-Force wheels for the track.

Your alignment is far from right, especially in the rear. Too much rear toe will yield excessive of tire wear on the insides of the rear tires. I run zero toe front and a very slight toe-in on the rear. Our rear camber is -1.8 and we do run a very mild camber plates on the front to achieve 2.0 degrees negative camber on the fronts. This is a good mix between street use and some track use. I will say though, our's had the exactly the same caster stock as your's. Nothing to be concerned about.

What tire pressures do you run? If you can’t answer immediately off the top of your head, then there’s a problem. I run 42 front and 38 rear. 42 front keeps the outer edge from wearing any more than the center. 38 rear to keep the center from wearing anymore than the inner edge. Pressures should be checked once a month. Running them down 5 pounds for 1k miles will dramatically shorten the life of the tire. Under inflated, the tire will not have enough strength to keep it from folding over in hard cornering.

What tires do you run? I run the Michelin PS2s largely because they have a very large shoulder area and survive well under the M5’s weight. I got 44k miles out of the first set.

How do you drive the car? The M5 has gobs of power. Applying throttle at the wrong place in a turn will cause the car to push unmercifully (front tires loose traction) and severally scrub the front tire outside edges. Done right you’ll brake later before a turn to transfer weight to and keep the car’s weight on the front wheels during turn-in and not apply throttle until later in the turn as you start to unwind the wheel. This is a skill well taught in our drivers’ schools. Any thoughts to attending? The car tells you what it likes and what it objects to, you just have to have the skill to feel it and work with it accordingly. If nothing else, for your tire's sake.

Nick325xiT 5spd
02-22-2010, 10:37 PM
Uh, the problem is that he has WAY too much toe IN in the rear.

glindsay
02-23-2010, 07:19 AM
Uh, the problem is that he has WAY too much toe IN in the rear.

Nick is correct, the rear is too much toe in, not toe out. Sorry, I mis-read the fuzzy image. Prior post edited accordingly. Greg

TimInNOVA
02-23-2010, 08:13 AM
glindsey:

Thanks for all of the great feedback. My M5 is wearing Michelin Pilot Sport A/S Plus and I have been running 45lbs in front and 40lbs in the rear.

As I said before, This past fall I replaced the lower control arm bushings recently with those from an X5. At the same time I also replaced both rear upper control arms and lower ball joints. I did not do an alignment afterwards (shame on me) as I hade marked up everything before disassembly. I'm sure my handy work is partly responsible for my rear toe issues.

Last night I was reading through the most recent issue of der Bayerische, and I saw the ad for "Alexandria Bavarian Service" on page 26. They are closer to me than RRT is. Have you had any experience with them?

TimInNOVA
02-23-2010, 08:32 AM
As it turns out Alexandria Bavarian Service does not have their own alignment rack. I just made an appointment with RRT. I'll post my new alignment specs afterwards.

Thanks again everyone. I'm glad I joined the National Chapter!

bmwcs3
02-23-2010, 08:33 AM
ABS will send you down the street to Wagonwerks who does great alignments, the way BMW specifies, with weights on the front seats.

TimInNOVA
02-24-2010, 08:37 PM
Thanks to all for the feedback.

Today I took my M5 to Road Race Technologies in Sterling, VA. They don't have their own alignment machine, but they prepped my suspension before taking it to their partner shop which has one. Turns out a lot of the new suspension bits I've had installed were tightened down with the suspension in "full droop", so they loosened things up and then tighten them down with the suspension at ride height. The new before and after specs are attached.

The car feels great now.

1125

uptownautoservice
02-26-2010, 03:33 AM
well, Too much rear toe will yield excessive of tire wear on the insides of the rear tires.

Nick325xiT 5spd
02-26-2010, 08:32 AM
well, Too much rear toe will yield excessive of tire wear on the insides of the rear tires.

It's also very unpleasant to drive around with.

uptownautoservice
03-18-2010, 07:04 AM
By the way, Where in NoVA are you?

S2KSEOUL
03-19-2010, 11:41 AM
I just installed H&R coilovers on my S2000 and had PBC Automotive in Chantilly take care of the alignment. Got the specs I wanted from the S2K forums and the guys did a great job. They work on Spec miata cars and the owner Pete has been tracking cars for years. They also do the work for the modified Vipers in the area.

onboost
04-05-2010, 11:44 AM
Late to the party, but J & F Motors has a very nice alignment rack and they know how to use it! Excellent suspenision set-up work.