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Old 06-15-2012, 03:30 PM
Palantirion's Avatar
Palantirion Palantirion is offline
Z4 Mvangelist
Location: Southern CA
Join Date: Jun 2006
Posts: 4,249
Mein Auto: 2003 M5-S2, 2002 540iT-S2
Scatha, at Coast MotorWerk's Huntington Beach location:


According to Jay at Ground Control, who examined full-res pics I sent him, this was not a sudden failure. He told me it looks like the bar cracked slightly, that this crack lengthened over time and then finally split quickly. The latter I can confirm noticing at the last OCRC event. As to the slow decay of spring resistance over time, I believe this was responsible for for the lag in rear end set response over the past year or so that I had thought due to failing RTABs. Jay was great to work with and sent me out a new bar free of charge, with a UPS return label so they can examine the failed bar to see how it happened.

So I had already ordered Rogue Engineering (blue) RTABs. I will disclaim now that they did not recommend the blues for a street driven vehicle, because the blacks are a little softer and don't transmit as much road noise or vibration. Scatha is not at all quiet, between the noisy TCK shocks, monoball sway bar end links and r-comp tires, so I saw no harm in going for the stiffer bushing.

New sway bar installed:

Note sway bar clearance with RTAB removed:

This is beyond "Duke's of Hazard" travel range. Note the rubbing marks on the axle shafts. This was from several years ago at BMS when we tried to set the bar to it's stiffest setting. It looked like it barely cleared on the rack, but rubbed slightly during test driving. So we set it back to the middle. In that pic you can also see the paint scratched off the lower arm from the broken sway bar's dangling end link.

Any idea whose product these are??? I don't. And they aren't marked. I wasn't at BMS when these were installed. I know BMS was making their own at the time, but the finished version of those was green. Anyway, these seem to have done their job ok. Still in good condition.

Removing the old RTABs. The technician Brandon (who was great btw) told me these were replaced from original, as they are a BMW part used for replacement not during factory installation. No doubt changed during the installation of the limiter bushings.

Bushings seem fine.

Rogue bushings installed:

Collar back on:

Back on the ground:


The car feels tight as hell now, which should surprise no one. I haven't had a chance to drive it hard on an interesting road yet, but expect to this weekend.

The next update will involve using commercial floor polish on the paint. Stay tuned for craziness.
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