[BimmerGuyHere]

I have a 2008 BMW 328i Coupe 6 speed...

I found the problem of my car swaying in the rear, my Rear Lower Trailing Control Arm driver side broke almost completely off some how!?

I have not hit anything or potholes so how did that happen, I only have 77k miles!?

Is this a simple take off and put the new part on or is there any pressing, torquing, etc?

Also I just had it in aligned (4-wheel) two weeks ago and four brand new tires, will I have to get it aligned again once I put the part on?

Thank you guys, photo below of my broke baby! 😭

part # 6763477

[Efthreeoh]

The trailing arm (lower control arm) has no adjustability, so it is just remove and replace. The only thing that could break that arm is someone used that suspension part to tie the car down during transport. It looks like a strap hook ripped through the steel arm. Hopefully you have impact tools.

How the alignment shop missed that damage is highly questionable.

[BimmerGuyHere]

Originally Posted by Efthreeoh

The trailing arm (lower control arm) has no adjustability, so it is just remove and replace. The only thing that could break that arm is someone used that suspension part to tie the car down during transport. It looks like a strap hook ripped through the steel arm. Hopefully you have impact tools.

How the alignment shop missed that damage is highly questionable.

Holy crap I didn't think of that you're absolutely right I had the car shipped to me on a flatbed a month ago!

Yeah I got an impact drill I'm going to do it today do I need to get it realigned you think?

Also I don't have a lift but I do have some ramps can I use that for the rear or does the tire have to come off? Thanks

[kkasson]

Normally you wouldn't need an alignment because that part is not adjustable. But since it was aligned recently, the current alignment might be off if that arm is slightly bent from the damage. So I'd recommend doing it again, yeah.

You'll absolutely need to lift the car with a jack instead of the ramps, that arm controls the position of the wheel so if if you were to take it off on the ramps then the wheel would move and bad things would happen.

Don't get under the car unless it's securely supported by two jack stands on the jack pads and the front wheels are chocked.

You do need to torque the bolts while the weight is back on the suspension, so the ramps are helpful there. You'll want to get the bolts most of the way installed and then put the wheel on and lower it down to the ramps and do your final tightening with the weight back on the wheels. Anything with a bushing like that needs to be tightened that way - the bushing kind of locks in to where you torque it so if you tighten it in the air with the suspension hanging then that becomes its natural position, and once you lower the wheels back down it ends up twisted and constantly under strain. Versus if you tighten it with the wheels down then that's where it wants to sit and it won't constantly stress it.

FCP Euro has a good DIY here. This is for installing different adjustable ones, but the process is the same. https://www.fcpeuro.com/blog/how-to-...mw-e90-e82-e84

They torque it by lifting the hub instead of lowering it back on to the wheel, which also works but is a little tricky. As long as you can reach the bolts with the wheel on the ramps then that should be the better way to do it, but it can be tough to get a good angle.

[BimmerGuyHere]

Originally Posted by kkasson

Normally you wouldn't need an alignment because that part is not adjustable. But since it was aligned recently, the current alignment might be off if that arm is slightly bent from the damage. So I'd recommend doing it again, yeah.

You'll absolutely need to lift the car with a jack instead of the ramps, that arm controls the position of the wheel so if if you were to take it off on the ramps then the wheel would move and bad things would happen.

Don't get under the car unless it's securely supported by two jack stands on the jack pads and the front wheels are chocked.

You do need to torque the bolts while the weight is back on the suspension, so the ramps are helpful there. You'll want to get the bolts most of the way installed and then put the wheel on and lower it down to the ramps and do your final tightening with the weight back on the wheels. Anything with a bushing like that needs to be tightened that way - the bushing kind of locks in to where you torque it so if you tighten it in the air with the suspension hanging then that becomes its natural position, and once you lower the wheels back down it ends up twisted and constantly under strain. Versus if you tighten it with the wheels down then that's where it wants to sit and it won't constantly stress it.

FCP Euro has a good DIY here. This is for installing different adjustable ones, but the process is the same. https://www.fcpeuro.com/blog/how-to-...mw-e90-e82-e84

They torque it by lifting the hub instead of lowering it back on to the wheel, which also works but is a little tricky. As long as you can reach the bolts with the wheel on the ramps then that should be the better way to do it, but it can be tough angle.

Great information thank you very much!!

Would this be okay putting it on the jacks and put it on , tightening my hand and then lowering it on its four wheels , and then torquing it?

[kkasson]

I don't think you'll be able to reach the bolts if it's on the ground. You need to torque the one side and counterhold the bolt on the other, and I doubt you'll be able to do it if it's sitting on the wheels. But if you can reach then yeah that works. If you have someone to help you with the other wrench it might be doable

[BimmerGuyHere]

Okay I got it off now I got a new problem I put one side on bolted it loosely but it doesn't fit it's off like a half an inch how am I going to move that to make it fit? The other one came off no problem easy

[BimmerGuyHere]

Originally Posted by BimmerGuyHere

Great information thank you very much!!

Would this be okay putting it on the jacks and put it on , tightening my hand and then lowering it on its four wheels , and then torquing it?

I got it off the old one came off really easy but now I got a new problem the new one I put it on one side but the other side it doesn't reach it's off by half an inch how do I make it reach?

[kkasson]

If it's just off slightly then you just need to pry it a little to line things up. Take a look at this video

around 12:12 here

If it's off a ton then maybe something else is bent or messed up but if it's only actually half an inch like this then you probably just need to pry it a little to get it lined up. All of the other bushings are putting pressure on the hub so it won't exactly line up without a little leverage.

[BimmerGuyHere]

Originally Posted by kkasson

If it's just off slightly then you just need to pry it a little to line things up. Take a look at this video

around 12:12 here

If it's off a ton then maybe something else is bent or messed up but if it's only actually half an inch like this then you probably just need to pry it a little to get it lined up. All of the other bushings are putting pressure on the hub so it won't exactly line up without a little leverage.

the old one came off easy, everything looks good!

Yeah my is off just like the video same amount, let me try that to pry it, thanks!!! wish me luck!

[BimmerGuyHere]

Okay I finally got it on now I'm going to take it to my mechanic to have it torqued correctly I guess this is necessary for this I'm not sure? Also the guy in the video does it up in the air I heard you need to have all four wheels on the ground before torquing??

[Ohio Enthusiast]

The goal is to torque the bushings at ride height, otherwise they'll be twisted a little all the time. This reduces their lifespan and affects suspension response a little (acting like a small change in spring rate).

I typically jack the wheel up to about ride height (it helps if you measure before lifting the car or know the specs). Sometimes you need to disconnect the sway bar to avoid binding it and not being able to lift one wheel to ride height (you'll start lifting the whole car before that).

Another option is to drop the wheels on some wheel blocks/cribbing (not cinder block - they're too crumbly to support a car). Need to keep the other side lifted about the same height so the car is parallel to the ground.

[BimmerGuyHere]

Originally Posted by Ohio Enthusiast

The goal is to torque the bushings at ride height, otherwise they'll be twisted a little all the time. This reduces their lifespan and affects suspension response a little (acting like a small change in spring rate).

I typically jack the wheel up to about ride height (it helps if you measure before lifting the car or know the specs). Sometimes you need to disconnect the sway bar to avoid binding it and not being able to lift one wheel to ride height (you'll start lifting the whole car before that).

Another option is to drop the wheels on some wheel blocks/cribbing (not cinder block - they're too crumbly to support a car). Need to keep the other side lifted about the same height so the car is parallel to the ground.

But the guy from FCP Euro torqued them in the air wheels off!

I find it too hard to do it with the wheels on it.

[Ohio Enthusiast]

Originally Posted by BimmerGuyHere

But the guy from FCP Euro torqued them in the air wheels off!

He lifted the wheel to ride height using a screw jack, at the 16:37 mark.

[BimmerGuyHere]

Originally Posted by Ohio Enthusiast

He lifted the wheel to ride height using a screw jack, at the 16:37 mark.

Oh okay well I'm going to take it to get realigned I guess I'll just tell them to torque it,

I've got the right torque settings 100Nm and I'll tell them to put it to ride level!?

I just hand tightened it not too tight while it was on ramps in the rear so that's pretty close to ride level, drives perfect now no more swaying!!

Anything else I missed? Thank you

[Ohio Enthusiast]

Originally Posted by BimmerGuyHere

I've got the right torque settings 100Nm and I'll tell them to put it to ride level!?

They would need to loosen the bolt and then re-tighten it to the right torque. Doing that on the alignment rack (basically a 4 post lift that the car sits on and the tech has access to the suspension from the bottom of the car) ensures the wheels are at static ride height.

[Efthreeoh]

Originally Posted by BimmerGuyHere

Holy crap I didn't think of that you're absolutely right I had the car shipped to me on a flatbed a month ago!

Yeah I got an impact drill I'm going to do it today do I need to get it realigned you think?

Also I don't have a lift but I do have some ramps can I use that for the rear or does the tire have to come off? Thanks

I'd be calling the shipper with a WTF! calibration. I still can't believe the alignment shop missed the damaged control arm because I just don't think with that damage the rear end could have been put into alignment. I would seriously suspect the alignment shop didn't do shit to align your car. Just saying.

My advice, based on 37+ years of BMW ownership, the best alignment results come from using a BMW dealership for alignments. Independent shops, especially generic tire shops can't properly align BMWs. Even most BMW indy shops don't get it right.

A BMW dealer would not have missed a damaged trailing arm.

[BimmerGuyHere]

Originally Posted by Efthreeoh

I'd be calling the shipper with a WTF! calibration. I still can't believe the alignment shop missed the damaged control arm because I just don't think with that damage the rear end could have been put into alignment. I would seriously suspect the alignment shop didn't do shit to align your car. Just saying.

My advice, based on 37+ years of BMW ownership, the best alignment results come from using a BMW dealership for alignments. Independent shops, especially generic tire shops can't properly align BMWs. Even most BMW indy shops don't get it right.

A BMW dealer would not have missed a damaged trailing arm.

Yeah but it'd be hard for me to prove they did it it sucks!

It drives good now so I'm pretty happy it wasn't that big of a deal to swap that part I had a friend do the alignment he's got a $200k laser alignment machine and charged me 80 bucks- BMW wants $269 that's too much for an alignment!!

If these ever break again im going to upgrade to the FCP Euro ones, they look way stronger!

I did take a picture of it on the toe when it got to me.

[Efthreeoh]

Originally Posted by BimmerGuyHere

Yeah but it'd be hard for me to prove they did it it sucks!

It drives good now so I'm pretty happy it wasn't that big of a deal to swap that part I had a friend do the alignment he's got a $200k laser alignment machine and charged me 80 bucks- BMW wants $269 that's too much for an alignment!!

If these ever break again im going to upgrade to the FCP Euro ones, they look way stronger!

I did take a picture of it on the toe when it got to me.

Attachment 3945967

Probably hooked the strap to the trailing arm, started ratcheting it down and it ripped right through. No other way that type of damage occurs.

Did your friend put the proper weights in the seats as called for by BMW's procedure?

[BimmerGuyHere]

Originally Posted by Efthreeoh

Probably hooked the strap to the trailing arm, started ratcheting it down and it ripped right through. No other way that type of damage occurs.

Did your friend put the proper weights in the seats as called for by BMW's procedure?

But these Rear Lower Trailing Control Arms are filmy, would think BMW would had make better ones! I get that they are designed to collapse so they don't puncture the gas tank, but still!

[N54Luis]

It’s a simple fix, just replace the part lol. I’d recommend undoing the shock bolts at the bottom and loosing the caster arm (i believe) it’s the thickest one and placing a jack under it to slowly release tension and it’ll make it so much easier for the control arm that’s broken to come out. You would need an alignment again, atleast just the rear.

[Efthreeoh]

Originally Posted by BimmerGuyHere

But these Rear Lower Trailing Control Arms are filmy, would think BMW would had make better ones! I get that they are designed to collapse so they don't puncture the gas tank, but still!

They aren't flimsy in the direction of force they are designed for. Weight reduction is king with BMW's suspensions.

I've said it a thousand times on this forum, a technician unfamiliar with BMW will fuck up a BMW in no time flat (this being the tow truck driver in this case).