Upgraded toe arms.
The stock toe arms are rubber bushed and can deflect under load, resulting in rear steer under heavy acceleration or wheel hop. M3 toe arms are the obvious first choice, as they provide a ball joints at both ends resulting in an arm that freely rotates but has negligible deflection which results in almost no toe changes under heavy loads.
Unfortunately the M3 toe arms do not fit, as they are designed for an M3 subframe which has differnt pickup points for the toe arms, resulting in a different length. Aftermarket toe arms either use unsealed joints (wont last long) or just use rubber bushed joints (pointless). Theres only a few with sealed joitns but are hard to source and become stupidly expensive once landed in Australia
fe1rx has custom made some fancy toe arms for the 135i which used the M3 bushes fitted into a custom made alloy arm. Unfortunately they are not for sale but has inspired me to make up my own solution.
I figure the best idea is to just use oem parts so looked at whether it would be possible to fit a ball joint into the factory toe arms. The stock factory rear upper link has a ball joint and is available separately for repairing an arm.
I found that while the ball joint is not avilable as a part number from BMW, it is available as a joint from Meyle or in my case FEBEST BMAB-044Z:
http://www.ebay.com.au/itm/172556729...%3AMEBIDX%3AIT
Theres an error with the listing saying it is compatible with the toe arm bushings. This is wrong and it is actually the bushing for the upper control arm.
The width of the bushing is identical to the toe arm but the diameter is slightly larger. If I remember correctly it was around 45.50mm. The diamter of the toe arm bushing is approximately 44mm, but needed to be slightly oversize to press in snugly. As I have a lathe, machining off a mm is not a big deal and can be done pretty easily. These bushings will not work unless theyre machined down.
I tried using combinations of threaded rod to press the machined bushings in but did not have luck. The threaded rod tools would not reliably press the joint in squarely and usually resulted in the joint not going in straight. I managed to get one joint in but couldnt get the 2nd joint into the arm to complete it. The project sat on the shelf for several months and I almost forgot about it.
Recently I just got a shop press, as I found I really needed one for a lot of small jobs. Made it really easy to press in the joints, I really should have made them more oversize and relied on the brute force of the press to get them in. I did around a 44.15mm sizing but shouldve gone 44.30. This would have resulted in a much tighter fit. A couple of them were a little loose. So I ended up having to tack weld them in to ensure they don't move. Not ideal but looks like the bushings survived ok. Once my old toe arms are removed I will make a 2nd set with a tighter fit and keep these ones as spare.
Gave the upgrade toe arms a lick of paint to cover the tacks and ready to go on the car!
Big thanks to
titium for supplying the spare toe arms