Thrust Arm Bushings - The Unofficial BMW M5 Messageboard (m5board.com)

Ocean's M5 · 28th February 2006, 20:38

Is there a way to check and see if the Thrust Arm Bushings are slightly bad or worn? Or, Does it just break totally?

I feel a slight shimmy occcasionally on Breaking at high sppeed.

Lastly, Is it a DIY project?

Beamer_usa · 28th February 2006, 20:46

Have you checked your rotors, make sure their not warped? as far as the bushings they wear down gradually.

cosioboy · 28th February 2006, 20:47

On a lift I would think you should be able to see and inspect them.

I am about to replace mine pretty soon and will be running 275s up front on rear rims with spacers. I am thinking of using the allegedly more durable bushings frm the X5 4.8is. I believe Mike has installed these and is running them for a few months now, so maybe he can share his thoughts. Same exact fit, but I suspect more durable, so you may want to consider that if it is indeed your issue.

The shimmy while breaking at high speeds could be an indication of an uneven pad deposit on your rotors. An easy procedure described on Dave Z's and Stop Tech's website will clear these (basically a series of high speed controlled stops).

mottati · 28th February 2006, 20:48

it is a slow, gradual change. A good independent shop should be able to tell if they're getting worn, based on play in the suspension links.
I recently upgraded to X5 bushings, which seem to be a little 'beefier', so we'll see...
Mike

cosioboy · 28th February 2006, 20:51

Quote:

Originally Posted by Beamer_usa

Have you checked your rotors, make sure their not warped? as far as the bushings they wear down gradually.

Warping and rotors are two words that do not go well together

The myth:
http://www.stoptech.com/tech_info/wp...rakedisk.shtml

Here is the removal procedure:
http://www.stoptech.com/tech_info/wp_padremoval.shtml

PS
Mike, we must have been typing simultaneously, I was just referring to your X5 bushings...

mottati · 28th February 2006, 20:56

Quote:

Originally Posted by cosioboy

PS
Mike, we must have been typing simultaneously, I was just referring to your X5 bushings...

You just beat me! So far so good with the x5 bushings. I haven't had the car on the track since, but street driving is good. Nicer response than the old bushings (one of which had failed within about 10k miles of install, i think must have been a dealer install issue) but no harshness etc.
Mike

palantirion · 28th February 2006, 21:17

Quote:

Originally Posted by Ocean's M5

Is there a way to check and see if the Thrust Arm Bushings are slightly bad or worn? Or, Does it just break totally?

I feel a slight shimmy occcasionally on Breaking at high sppeed.

Lastly, Is it a DIY project?

If you're in southern CA, anywhere near Santa Ana, I'd take it to BMS. They've diagnosed the same problem with my beast when I thought I had a brake problem and coached me on how to get the dealership to replace the bushings under warranty. I'm getting ready to replace mine for the second time, although this time I may skip the dealership and have BMS replace them with the X5 bushings - stock M5 bushings die quickly with bigger tires and track driving.

You can contact BMS at 714-429-0257. Ask for Chris or Mike and tell them Earl sent you.

imolaman · 28th February 2006, 21:19

Has anyone tried "skimming" their rotors to remove deposits and perhaps the odd high spots? I have made an appointment with a reputable brake fitment centre as I also have a slight vibration under hard braking. I initially ruled out the thrust arm bushings as they were replaced about 10 000 km ago. Now reading Mike's reply about his bushings failing again so soon it might warrant a trip back to the dealership for a little warranty claim. On skimming the fitment centre claim they do not remove the rotor from the vehicle, only the wheel and the caliper set, then they just skim a very tiny amount of metal off the surface, enough to remove the now famous brake pad deposit and any high spots that might have developed over time.

Would be interesting to hear opinions from others before I do the skimming.

Rudi

emccallum · 28th February 2006, 21:23

You can take a large screwdriver and a good light and check them. Look for cracking and play. Even new ones tend to have some cushion to them. It will be apparent once you see them up close if they are cracked. I think it is a DIY, however, I have no idea your comfort level. Two ways to do them. One is to replace the entire control arm with the bushings allready in place. That is probably the most straight forward, but more expensive method. The other is to replace only the bushings. I replace only the bushings, using a bushing press that doesnt require the control arm to be removed. After about two or three swaps the tool pays for itself...I like tools so any excuse to buy one suits me. Just make sure the bushings are put in properly, and the bolts are torqued with the suspension weighted (wheels on the ground/ramps etc.). I think you need to remove the sway bar brackets on the m5 to get the bolt out...along with moving the steering arm to just the right place! Front end alignment after installation wouldn't hurt. Find out how much a dealer/shop charges then make the call.

ernest

Quote:

Originally Posted by Ocean's M5

Is there a way to check and see if the Thrust Arm Bushings are slightly bad or worn? Or, Does it just break totally?

I feel a slight shimmy occcasionally on Breaking at high sppeed.

Lastly, Is it a DIY project?

gsfent · 28th February 2006, 22:40

Quote:

Originally Posted by mottati

to X5 bushings, which seem to be a little 'beefier', so we'll see...
Mike

X5 standard or 4.8i?
Regards,
Jerry