On parts 31126774825 and (6) was there a BMW part number molded into the aluminum arm?

On my car, the wishbone arm has a BMW number molded in but the tension strut arm does not.

Thanks.

 

Here are the folks that forge the control arms for BMW:

OTTO FUCHS KG: Chassis, Suspension, Forged wheel, Lower Control Arm, Transversal Link, Link Assy, Traction Link, Housing, Flange, Spline Housing

 

This was a very helpful post. I did mine today, and the only real problems that I had was not having the right size wrench for the ball joint nut (21mm?), and not supporting the brake assembly before I loosened the pinch collar (strut pulled out by over 1", and I had trouble getting it back up). Jacking is also not easy on a lowered model, but I jacked how he showed it, and it worked.

 

Very helpful post indeed!! Just finished mine over the weekend. Just the passenger tho, it was the worst (loud banging noise during braking ). That is the EXACT same press I bought !!!

 

I love your writeup. Awesome job! Quick question; can you elaborate as to why the spring compressor was used? I found this online: BMW DIY Video – Replacing Control (Thrust – Strut) Arms on Late Model BMWs, E60, etc. | Bavarian Autosport Blog : Replacing Control (Thrust-Strut) arms... and they did not use a spring compressor. Did you use it to r&r the control arm (wishbone) or the radius arm (tension strut)?

 

I was told that you need to tighten bolts while the car is on the ground and not while it's on jacks. They if tightened while on jacks when cars weight comes down it can damage the bushings.

 

I found that the proper torque was essential for the finishing touch on replacing my control arms. My torque wrench is getting old, and was too conservative the first time, and went back for a final tightening, all is fantastic now, car is just like new! In fact can go for a very fast 80+ to slow with brakes and hands off the steering wheel and it stays perfectly straight !

btw, I have the sport suspension package.

 

I just replaced my front lower control arm bushings with urethane, and they make an incredible difference.

Contact Jon at Problem Solving Polyurethane PSB Bushings | Armstrong Distributors

They do noticeably transmit more road contact, but worth every penny of the $84.50/pair bushing cost.

The urethane bushings are pressed in first and then the metal sleeve slides in after the pressing.

This way it does not matter if tightening is done w/o the vehicle weight. There is nothing to tear!

I had an earlier 7 series that went through three (3) OEM bushing replacements in 2 years. The OEM are crap!

I just redid the shocks and springs, and that uncovered other F/E issues immediately such as inner/outer tie rod which were replaced last W/E.

However, the front end now feels like my Ferrari did -tight, quick, and very controlled.

I am thinking of doing the lower rear front control arm bushings as well very soon.

I highly recommend urethane bushings. Armstrong is a bit more limited in e60 F/E bushings than is Powerflex, but their products are great.

 

Tightening procedure is a little complicated, not bad. I have a 2007 530xi in North America, so its just info for that model. Rockauto.com and others say the x-drive models in Europe actually have the North American 2wd tensions struts, so be careful when ordering!!!

Description of how to do it in the Bentley BMW 5-series (2004-2010 E60 models) shop manual:
(This one is specifically for the AWD X-drive, like 530xi, versions only. See a similar description elsewhere for the 2wd (like 530i) versions, since the ball joint attachment procedure is more complicated on 2wd models.)

---Install bushing end of tension strut to subframe using new fasteners only.

---Do not fully tighten bushing tension strut nut at this time (when the weight is off the wheels). You will tighten the nut now to 74 ft-lb only, and you'll do more later when the car is on the ground (see steps below).

---While the car is still up in the air, install the tension strut to the knuckle ball joint on this x-drive AWD model. Use a new nut, and tighten all the way to 122 ft-lb.

----Put the wheel back on and torque the road wheel to the hub at 89 ft-lb.

----Lower the car to get the all the car's weight on the wheels.

----Bounce the front suspension a few times. (I assume a "few times" means 5.)

----With car still on the ground, tighten the tension strut bushing nut by rotating the nut tighter by 90 degrees (not a torque value here, just tighten the nut by rotating it 90 degrees).

Note: The tension strut bushing nut tightening procedure also applies to 2wd models exactly as described above. Only the ball joint attachment procedure is different, and on the 2wd models this involves pinch bolts, etc.

Note: The above is really for North American AWD 530xi X-Drive type models, although its really only the ball joint end of the tension strut that has a more complicated procedure in the 2wd models such as the 530i.

I just ordered OEM Lemforder-TRW tension strut control arms for my '07 530xi AWD version using part numbers 31106770685 and 31106770686, left and right ones. From oembimmerparts.com for $262 for the pair. .... (Note Amazon.com and Rockauto.com consistently show the wrong ones when you tell their web pages you want one for the AWD X-drive 530xi versions!!! Careful. Get the right ones.) The new bushing is already installed on the fresh arm, not pulling/pressing required, which might damage the old arm if I just pressed in new bushings. ... BTW, have you ever seen such an organic-cyborg-twisty-curvy optimized part on any suspension like this one?


Then I went to Rockauto.com and got cheap (I know, I know....) ball joints, Mevotech MS10523 for $48 for two of them. At least I splurged on the tension struts, getting new Lemforder-TRW ones there.

For about $320 including shipping, and I'll do it myself, I can change out the tension struts and ball joints on my 530xi. Has anyone used macautoparts.com, a New York City area outfit that has the strangest, worst website, as they say they have been doing business since 1978, yet they say "over 100,000 happy customers served", which is NOT very many in a 37 year span! LOL, I guess the rest weren't happy? Anyway, macautoparts.com does have very cheap no-name tension strut control arms, as in $170 for two, if you trust no-name control arms.

 

I attempted to do the tension strut (see above) and ball joint replacements. I stripped out the torx fitting on the end of the ball joint stud trying to remove the ball joint nut. I then took the car into the dealership. I asked them to use new fasteners (nuts-bolts) everywhere, as the Bentley Manual, the on-line BMW service manual procedures, and the Service Advisor guy and I told them. They didn't use any new fasteners, so I got a $267 refund when it was done. I still paid for a pricey $150 alignment.