BMW M5 Forum and M6 Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
91 Posts
Discussion Starter #1
Hi All,
I am a proud new ownewr of an 03 M5. I LOVE the car, but I was having the dreaded 50mph shimmy in the steering wheel, and I am running 9.5 rims up front. I decided to have the bushing replaced with the x5 parts after reading up on this site. According to receipts I have, my thrust arm bushings were replaced only 20K miles ago. The car wasn't tracked or abused, turned out the bushings were probably installed incorrectly. The indy shop I use that specializes in BMW's explained why in his experience the bushings fail prematurely. He feels that while the car is in the air (wheels hanging, struts extended) the bolts that run through the center of the bushing should not be tightened, just snugged up. After the bolts are snugged, the car then has to go on a drive-on, alignment style lift where the car is sitting at normal ride height, which is when the bolts are fully tightened. He further explained that if the bolts are tightened while wheels are hanging, when the weight of the car comes down it tweaks/twists the rubber of the bushing due to the load. Instead, if the bolts are tightened with the full load on them, there is no twisting of the rubber due to the load. Just wanted to share this info as I had never read anything on this board regarding this install technique, but it make perfect sense... Shimmy all gone, back in business.
 

·
Registered
Joined
·
848 Posts
Nothing new here, i think the way you're describing is how most people do it at least i hope, i just did another set yesterday and i preloaded (by jacking up the side I'm working on as the car is sitting on jack-stands) when i tighten the bolts. All control arms/bushings must be installed this way to avoid premature wear.
 

·
Registered
Joined
·
91 Posts
Discussion Starter #3
Oh good I'm glad! As I was reading up on the bushings there were very few mentions of technique, never crossed my mind either!
 

·
Registered
Joined
·
6,940 Posts
Agreed, this is common knowledge for those doing the actual install. If you are using Poweflex bushings, you do not have to preload to tighten anything.....

Useful post none the less for those who missed the fine print.

Thanks for posting!
 

·
Registered
Joined
·
595 Posts
Agreed, this is common knowledge for those doing the actual install. If you are using Poweflex bushings, you do not have to preload to tighten anything.....

Useful post none the less for those who missed the fine print.

Thanks for posting!
Timmay,
Are the powerflex bushes the way to go,or is the ride comprimised??
 

·
Registered
2002 BMW M5
Joined
·
1,368 Posts
Hi All,
I am a proud new ownewr of an 03 M5. I LOVE the car, but I was having the dreaded 50mph shimmy in the steering wheel, and I am running 9.5 rims up front. I decided to have the bushing replaced with the x5 parts after reading up on this site. According to receipts I have, my thrust arm bushings were replaced only 20K miles ago. The car wasn't tracked or abused, turned out the bushings were probably installed incorrectly. The indy shop I use that specializes in BMW's explained why in his experience the bushings fail prematurely. He feels that while the car is in the air (wheels hanging, struts extended) the bolts that run through the center of the bushing should not be tightened, just snugged up. After the bolts are snugged, the car then has to go on a drive-on, alignment style lift where the car is sitting at normal ride height, which is when the bolts are fully tightened. He further explained that if the bolts are tightened while wheels are hanging, when the weight of the car comes down it tweaks/twists the rubber of the bushing due to the load. Instead, if the bolts are tightened with the full load on them, there is no twisting of the rubber due to the load. Just wanted to share this info as I had never read anything on this board regarding this install technique, but it make perfect sense... Shimmy all gone, back in business.
That is how the repair procedure is described in alldata, too bad many shops don't follow it... :dunno:
 

·
Registered
Joined
·
450 Posts
A lot of dealers & indy miss this critical step

My wife's 530i had the front end shimmy a couple yrs ago, so had the bushings replaced at local stealer. Within 8k miles was back in full force. Dealer at first said brake rotors, then finally said bushings had failed. Re-done under the 12 mo warranty, but clearly they had been installed improperly. When I asked the tech about pre-loading the car (with the proper weights in the seats), he looked at me like I was insane.

General rule if you're not doing it yourself (or standing there watching it done) is ask the mechanic to tell you exactly how they perform the work. If they don't mention this step run away.
 

·
Registered
Joined
·
6,940 Posts
Timmay,
Are the powerflex bushes the way to go,or is the ride comprimised??
Many will tell you Powerflex on this car is a no-no. I love them. No issues, no troubles, no noise, easy install, and to me, the ride is not harsh at all.....
 
  • Like
Reactions: abbas.ali

·
Registered
Joined
·
524 Posts
Thanks for posting. Just received replacements for my car (X5 type) am going to tackle this myself, so is it enough to jack the hub up to replicate load? How do you know you've jacked it up to the right position? Apologies for what may seem to some like dumb questions but relevant to me all the same.
 

·
Registered
Joined
·
848 Posts
take a look at the control arms geometry when the car is on the ground. when mine is on the ground the front control arm (not thrust arm) is horizontal to the ground. You will also notice the car will lift up the jackstand when you jack up the side you're working on to replicate the load.
 

·
Registered
Joined
·
1,872 Posts
Thanks for posting. Just received replacements for my car (X5 type) am going to tackle this myself, so is it enough to jack the hub up to replicate load? How do you know you've jacked it up to the right position? Apologies for what may seem to some like dumb questions but relevant to me all the same.
Before you start, measure the distance from the center of the wheel hub to the fender lip on both sides and record it. Then when the time comes, jack it up to that level.
 

·
Registered
Joined
·
1,031 Posts
There are many new folks here that may have not realized this was common knowledge or practice. We should be aware that this 'community' is ever growing/evolving.

I appreciate you taking the time to share your info allowing others to possibly benefit - good on you.
Vic
 

·
Registered
Joined
·
5,532 Posts
I think the powerflex or any polyurethane bush MAY not be suitable, because the stock bushing is designed to be relatively strong in horizontal axis loads (braking) BUT also relatively soft in vertical axis loads (ride comfort, going over bumps etc)

By definition the polyurethane bushing will be 'strong' in all directions.

Just my view.
 
  • Like
Reactions: jgfabs
1 - 14 of 14 Posts
Top