nOOb control arm bushing question - street car

#1

At the risk of inciting more “you might break a nail” comments from IndyJim, I have another question for you guys and gals about my street car suspension overhaul.

I am preparing to install my brand new, limited edition Jim Robinson DTOM Racing Aged-On-The-Shelf stock control arms on my cabriovertible. I have already pressed stock M3 offset control arm bushings into the lollipops.

The consensus on bf.c seems to be that liquid dish/laundry soap is the best lubricant for pressing the end of the control arm into the bushing hole. The factory manual specifies a special BMW product that I understand to be kerosene-based. That manual also states that you are supposed to use that goop, install the CA, bolt up the lollipop, then promptly lower the car to the ground and let it sit for a while (ostensibly to let that adhesive dry and bond the control arm to the bushing in the correct loaded position).

I am confused by the design because it looks like the arm would still need to rotate in the bushing. The stock CAB has more give than the M3, but still… Do you want the end of the control arm bonded to the bushing material? I guess I could use hairspray-in-the-bmx-handlebar-grip trick…

Thanks in advance.

#2

The point of resting the car on its wheels before the lube dries is to avoid pre-loading the bushing. In normal use the OE type bushing distorts with movement of the control arm rather than the arm rotating within the bushing.

#3

That makes sense, Jim. Is that also the case with the M3 bushing? I can easily see how the voids in the stock CAB would allow it to flex around, but the M3 CAB is more like a soft hockey puck.

Do you have a recommendation for what to use as the lube-turned-adhesive?

#4

I don’t think that it’s going to matter too much what you put on there to get the bushing on. The control arm shaft is going to rotate in the bushing because a hard bushing won’t distort and allow rotation like a soft bushing. Something has to rotate and if it’s not the bushing then it’s the control arm shaft.

My guess, drawing upon my vast experience* of suspension bushings, is that it’s not really the role of the CAB to resist control arm rotation at all. It just provides a secure but non-rigid means of anchoring the rear of the control arm. So I’d just warm up the bushing, put something slippery on the control arm shaft and fight that puppy on.

  • That was sarcasm.
#5

Caliper grease works well for this job.

Have you pulled the old control arms off yet? If not I will be keeping any eye out for you next thread entitled “How do you get to the inner balljoint nut”

#6

From what I gather, a stubby 22 mm wrench is one option (thanks Levie) and taking the motor mounts loose is the other option. Is that the ball joint you sometimes have to support with a jack to keep it from turning?

#7

A drop or two of soap in a 12 oz of water is all you should need. In a pinch, I’ve also resorted to the likes of windex. You do want something that will dry without leaving behind too much film.

FCAB’s are the bane of my BMW existence.

#8

7/8 (22mm equivalent) ratchet wrench:
http://www.craftsman.com/shc/s/p_10155_12602_00942165000P?keyword=00942165000&sLevel=0

Cheap and short. Since it is cheap, it can be shortened more if you want.

#9

Just did our car, FWIW, it was a 21mm on ours, I know because I had to borrow a crow foot to torque it on the reinstall. Also could not get a box wrench on it, only an open wrench would fit.

Not looking forward to next time.

#10

Just a tip:

The drivers side is no problem. The best way I’ve come up with to get the passenger side is from the top through the engine bay, you can get to it with some long extensions and a universal joint.

To get the ball joint to pop free of the subframe don’t be afraid to use a pickle fork and a large hammer.

#11

87isMan wrote:

Mmmmm. Pickles. Looks kinda dainty, but I am game.

Thanks for the guidance, guys. Seems like the crowd is split between grease and adhesive, so I am going with caliper grease since that will make installation easier. :laugh:

#12

What ever you do dont do this…:laugh:
http://www.youtube.com/watch?v=HpKOGaFqAuQ

What a moron.

#13

78kona wrote:

He JB welded the lollipop? Wow. Pretty dumb.

But not as dumb as getting out of the vehicle and walking around with his back to a “hot” track to check out the damage.

Just wow.:ohmy:

#14

what a moron…