E46 M3 BAD tramlining. Need help.

[thetypicalm3guy]

Actually that should be fine. No bolt goes through the bushing so no way to torque and preload it. The way to adjust preload on that bushing would be to press the rubber part out and clock it differently within the housing.

If you bought the entire assembly, it should come properly clocked. If you just bought the rubber part and pressed it in, it might be worth checking that it's clocked correctly.

Oh I see. I bought it already installed in the carrier arm.

[heinzboehmer]

Ah so sounds like I need to Redo my FCAB mounting bolts. That should be much easier to do!

Actually that should be fine. No bolt goes through the bushing so no way to torque and preload it. The way to adjust preload on that bushing would be to press the rubber part out and clock it differently within the housing.

If you bought the entire assembly, it should come properly clocked. If you just bought the rubber part and pressed it in, it might be worth checking that it's clocked correctly.

[thetypicalm3guy]

Only rubber bushings need to be torqued at ride height. Any ball joint or spherical bearing can be torqued in any position.

Reason is that if you torque a rubber bushing when not at ride height, the bushing will twist when you put the car back on the ground. This "preloads" the bushing and can cause weird behaviors and accelerated wear. Ball joints etc. rotate freely, so there's no way to preload them, no matter what position you torque them at.

Ah so sounds like I need to Redo my FCAB mounting bolts. That should be much easier to do!

[oceansize]

I’ve always torqued down FCA in the air. The bushing is shaped and it can only fit in one way. The bolt isn’t horizontal like the RTAB. I have no funky behavior. Could I be wrong, certainly.

[heinzboehmer]

Only rubber bushings need to be torqued at ride height. Any ball joint or spherical bearing can be torqued in any position.

Reason is that if you torque a rubber bushing when not at ride height, the bushing will twist when you put the car back on the ground. This "preloads" the bushing and can cause weird behaviors and accelerated wear. Ball joints etc. rotate freely, so there's no way to preload them, no matter what position you torque them at.

[thetypicalm3guy]

Guys, I followed this FCP Euro guide:

https://www.youtube.com/watch?v=usfbSLE_1aI&t=1157s

They did not torque down with the vehicle on the ground? Who has done it wrong?

[thetypicalm3guy]

Does this go for FCABS as well?

[thetypicalm3guy]

Damn, who would have thought. Okay, I will do this. Loosen all bushings and arms that I installed in the air, let vehicle settle down with all weight on floor, then torque down to required spec. Sound good?

[Arith2]

Check if there is a DIY Garage nearby, and they have a 4 post lift, makes for easy work.

Alternatively, drive the car onto ramps, then jack up the rear and put ramps underneath as well, lower it.
Push down on all 4 corners and let it settle to ride height (not ideal when having just jacked it up, but it will have to do).
Then loosen the bolt until the bushing relaxes and torque it down.

The four ramps thing is doable. The only issue will be settling the suspension but it's not that significant. Just making sure all four wheels are holding full weight is the most important part. I have an alignment rack to do it on but in the garage that's what I did. Shock bushings can be done without lifting the car but everything else with need a lift most likely.

[bmwfnatic]

You know what. This could be it. I definitely torqued down the control arms and tie rods on jack stands. How am I supposed to torque them down on the ground though?

Check if there is a DIY Garage nearby, and they have a 4 post lift, makes for easy work.

Alternatively, drive the car onto ramps, then jack up the rear and put ramps underneath as well, lower it.
Push down on all 4 corners and let it settle to ride height (not ideal when having just jacked it up, but it will have to do).
Then loosen the bolt until the bushing relaxes and torque it down.

[thetypicalm3guy]

I'm really wondering if this is the issue. Even hand tightened bushings will not relax unless fully slackened, loaded, and then tightened. A jack pushing up on the suspension will not do the job properly.

You know what. This could be it. I definitely torqued down the control arms and tie rods on jack stands. How am I supposed to torque them down on the ground though?

[Arith2]

Are you sure it's not an improper install of suspension? For example, if you tightened the bolts on the front control arms with the suspension unloaded it would drive weird, you need a preload when tightening those bolts.

I'm really wondering if this is the issue. Even hand tightened bushings will not relax unless fully slackened, loaded, and then tightened. A jack pushing up on the suspension will not do the job properly.

[FBloggs]

I understand that The dsc uses input from steering angle sensor to function correctly. If the steering angle sensor is relaying faulty info, there may be unwanted activity from the dsc,
Having said that, I'm going by the OPs perspective/description of the cars behavior..

I know from my example, tramlining was only one of several drivability issues that the car had.
Typically tramlining was the term used to describe the front tires following ruts or road camber.
It is an irritating trait, but not dramatic.
The rear axle can also exhibit tramlining if components are worn.

There was a comment by the OP that the car behaved as if he was driving drunk.
To me this suggests that the car has no straightline stability...problems at both ends, if constant steering adjustments have to be made.

[bmwfnatic]

In the mk60 cars, it talks to the dsc.

Yes, but how would that be related to tramlining?

[FBloggs]

In the mk60 cars, it talks to the dsc.