RRT Thrust arms!

[BigKriss]

I got my hands on these very recently and went to install them. I've only done one side so far. It took me about 5 hours total, to do the one side. I followed Bill R's excellent advice here. (http://www.bimmer.info/forum/showthread.php?t=5869&highlight=thrust+arm+bill) I wacked the old arm out mounting the bottom strut holder on some bricks, I don't have impact sockets. I left the strut in and unbolted the lower swaybar link, tie rod ball joint and the two control arms bolts. I changed all the steering links a few months ago, so everything unbloted really easy. It would be a lot easier with two people if one holds for strut for you as you have to align everythign correctly, but anyway, real men don't need a helping hand :)

How do you torque the bolts under load if you don't have some car ramps. I didn't torque the bolts under load. I think I torqued them around 80nm, with some 28? locktite. I've only done one side so far and the left is still the old arms. I haven't pushed the car yet. I'm waiting for the skies to clear (there was actually rain here!), so to give a full description of what they are like, will take a few more days. You can see the "bushing", little to no compliance. But initial vechile noise harshness suggests there is little change going over bumps.

I also found this link describing them. (http://bimmerforums.com/forum/showthread.php?t=170146&highlight=rrt+thrust+arms)


http://img288.imageshack.us/img288/2233/pict00417fv.jpg
http://img259.imageshack.us/img259/8627/pict00422bz.jpg
http://img219.imageshack.us/img219/4971/pict00457fe.jpg

[632 Regal]

I never saw bushings like that.

Chris, nail a bunch of 2 x 10s together if you cant afford ramps, to torque them under load it really has to be under the weight of the car or the bushings will get trashed in a hurry.

[mbogosia]

I installed some control arms on my old Passat and didn't tighten them under load. The inside bushings were trashed in under a month. They get all twisted like an indian sunburn.

[MBXB]

Chris,

Check out st1100ray's procedure for preloading the front suspension, esp the bit about 'relaxing' the load using a sledgehammer after you set the weight down.

I was surprised how much the suspension moved out to the side with a good whack.

http://community.webshots.com/photo/97381781/99458744PnHQyt

[BigKriss]

Thanks for the comments guys. I know I'm asking the same question, but do I need to torque them under load with these bushings?

[632 Regal]

unless they are ball bearing your answer is YES.

Thanks for the comments guys. I know I'm asking the same question, but do I need to torque them under load with these bushings?

[Johntee540]

Kriss - Email RRT and ask them. The Torque under load procedure was mandated by BMW to slow the failure of their poorly designed Bushings on our cars.

RRT will give you the definitive answer. My suspicion is that since these are metal Mil-Spec Bearings you just need to Torque to spec.

Hope this helps - Jt

[BigKriss]

Thanks John, I emailed RRT and I'll tell you what they have to say.

[Bellicose Right Winger]

Looks like a spherical bearing, which doesn't have to be tightened under load. The inner race of the bearing where the bolt passes thru should have been free to spin, unlike the center sleeve of the factory bushing.

The bearing is probably similar to the on page 348.
http://www.timken.com/industries/torrington/catalog/pdf/roller/plain.pdf

Paul Shovestul



..........I know I'm asking the same question, but do I need to torque them under load with these bushings?

[Chip]

Kriss-
You do not need to torque these bushings under load. Just torque to spec as John suggests. This is what Barry Battle (RRT) told me. You'll love these things. You might notice a slight increase in road noise, but the car sets-up much quicker on turn-in, almost seems like oversteer.
Have fun- and good luck


Thanks John, I emailed RRT and I'll tell you what they have to say.

[genphreak]

Thanks John, I emailed RRT and I'll tell you what they have to say.Seriously frikking nice Kriss, I didn;t know you were hard onto these things and gonna get them... :) VERY, very, NICE they look gorgeous. I am most impressed! :) Nick

How much are they???

[BigKriss]

How much are they???

They are around us$230 each.

[BigKriss]

If you are using our bearing thrust arms then you do not need to torque them
under load. I do not remember off the tp of my head what the torque spec is
but use the same spec as the factory or bently manual. I beleive it is 80
ft/lbs... Hope this helps.

Barry Battle