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Discussion Starter #1
Do the stock front control and thrust arms have roundel logos stamped in them? I noticed over the weekend that the arms on my car have the Lemforder logos on them. The original arms on my M3 had roundel identification markings so I was expecting the same on the M5. Can I assume these arms have been replaced in the past? The thrust arm bushings also have contitech bushings in place. The ball joint boots appear to be in good shape.

I am trying to determine what components of the front suspension need to be replaced as I chase down a front end vibration under light braking. I currently have 107k on the car. My original plan was to replace the thrust arms with new Lemforder units. However, if the arms have been replaced relatively recently I may just replace the bushings.
 

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Trying to remember? I have a set of new OEM arms at home sitting in my parts pile, will take a look when I get home in about 10 hours. I know the TRW tie rods have both roundel and TRW stamp on the OEM items, but just the TRW if not dealer supplied. The Hella oil temp sensor I bought you can actually see where the BMW roundel was machined off for second source sale.

I also think the Lemforder control arm bushings I bought had Contitech stamped on them? But the X5 bushings I bought had the Lemforder stamp. Lemforder makes the OEM arms for BMW. So they will have the Lemforder stamp if OEM, but also think there should be a roundel too if OEM.
 

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On my 3/2000 build both the thrust and control arms have "BMW"and the part number. Also, Lemforder symbol and date code of 12/99. My original set of thrust arms had a set of Contitech bushings that were pressed-in and date coded 2007(X5??), I removed them in 2010, they were still in good shape. My current set of Lemforder thrust arms had Boge bushings, I doubt they lasted 10K miles before the thrust bushing split off the side(crap). Just pressed in Powerflex bushings. I would not bother to install that Boge crap in my car again. See pictures of arms.
 

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if the arms have been replaced I would think it's either ROTOR DEPOSITS or STEERING RACK

I've got the same issue on my car, everything is BRAND NEW except for the steering rack and I still get a shimmy under braking at ~50-70mph

It does go away if I go on a 100 mile drive were I get the chance to clear the pads and rotors with some hard braking. My daily commute is very docile and the brakes probably never get up to a good temperature.

EDIT:

14/July/2015

My shimmy was caused by my H&R 5MM spacers

5mm is the middle option for the smallest-spacer (3mm) and next largest-spacer with a built in hub (10mm), what happens is the wheel becomes Bolt-Centric instead of Hub-Centric so you will get a shimmy/vibration/shake at certain MPH.

I've not tried 10mm spacers because I saw multiple people reporting that H&R has a design flaw in the 10mm spacer (ONLY the 10mm AFAIK). The built-in hub is NOT flush with the spacer resulting in the wheel NOT sitting flush and yet-again NOT hub-centric


 

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OP I checked my extra sets of control arms and the OEM ones have BMW & the part # on them, just like PrescottM5's pictures show. On the other side of the arm where the BMW mark is you should see the Lemforder triangle. The Lemforder equivalents I have are identical, but blank metal where the BMW casting is on the OEM ones.

I've found most of the front end shakes on these cars are caused by a combination of worn part(s) AND marginal wheel balancing.
 

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Discussion Starter #7
Thanks for the pictures and input everyone. So that confirms that my front control and thrust arms have been replaced. Likely somewhere between 75k and 100k miles (when I acquired the car). The PO bought the car from EAG, so maybe they did some of the work.

I will look at the center link and tie rods, but I don't feel anything else that would lead me to believe the steering linkages are worn. Here is an outline of my issues:

- Brake judder above 50mph under light braking
- Under heavy braking no judder
- Shaking felt in steering wheel, minimal vibration feel in brake pedal
- Front end otherwise stable when pushed
- Inconsistent, sometimes strong shaking, sometimes none (potentially a sign of deposits?)

I'll look at the pad deposit issue on the rotors again. I flushed the fluids about two months ago, but didn't notice what kind pads are on the car. The rotors are cross-drilled centric and lines are goodridge braided stainless. I've never been a fan of cross-drilled rotors, I could swap some OE blanks and re-bed the pads to see how that helps.
 

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ut two months ago, but didn't notice what kind pads are on the car. The rotors are cross-drilled centric and lines are goodridge braided stainless. I've never been a fan of cross-drilled rotors, I could swap some OE blanks and re-bed the pads to see how that helps.
I have cross-drilled centric rotors aswell + stoptech pads

I too would've preferred the slotted rotors
 

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Yeah if you have judder, probably brakes. Double check wheel balance if you haven't already done so. If you have a spare set of OEM disks then worth a try for sure. In the past I've lightly sanded used pads on a large flat board to re-surface them prior to trying them on a different set of discs when hunting front end shakes. May cut down on the pad bedding in time.

I also meant to add earlier that the non BMW Lemforder arms I have, have Contitech bushings in them, that came from Lemforder. So Conti & Lemforder are partnered in some way. Box the bushings came in said Lemforder.
 

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Discussion Starter #12
Wanted to follow up on this. I havent had the vibration for months. It does appear pad deposits were the issue. I went through the pad bedding process several times and haven't had this re-occur.
 
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