Rear Control Arms replace with Adjustables Control Arms

[drummerboi]

Hey you guys, I've searched but there isn't much detailed info about how to replace the rear control arms. I've read about one DIY but it was not detailed enough. Anyone who have done this please chime in. I'm just worried about the Diff, as that seems to be PITA... Anyone who has pictures, please share. Also, should I buy new nuts and bolts? Any info would be appreciated. Thanks.

[flyfishvt]

The only real reason to install adjustable lower control arms is if you have installed lowering springs or coil overs that throw the camber on the rear wheels off. If your alignment specs are good there is no need for them.

You ARE talking about the lower wishbone control arms aren't you?

Replacing them is a bit of a pain but not super bad. The hardest part is getting the upper bushing bolt out but you can search my threads for how I did that with a torch to heat up the rubber in the upper bushing.

You can reuse the old bolts.

[MParallel]

Some people say it can, but no way on my car I can take the bolt out out without moving the diff.

[jadidaskv]

just did it the other day. i torched the driverside and it wouldnt come outi loosened (didnt remove them all the way) the four bolts for the bracket that goes around the diff and unbolted the three bolts from the diff so i could lower the bracket and move the diff around to get the bolt out. i broke one lower bolt and bent one upper bolt. i wish i moved the diff around at first it would have saved a lot of time and made things much easier.

[drummerboi]

My reason for changing them is exactly due to car lowering. I got some nasty negative camber wear on the rear. Just order some adjustable arms.

[MParallel]

My reason for changing them is exactly due to car lowering. I got some nasty negative camber wear on the rear. Just order some adjustable arms.

You do know you can set the camber via the eccentric bolt that is at the end of the lower control arm? Range is limited, but could be enough. Mine is pretty low in the back but I only have slight negative camber.

[drummerboi]

You do know you can set the camber via the eccentric bolt that is at the end of the lower control arm? Range is limited, but could be enough. Mine is pretty low in the back but I only have slight negative camber.


yea i know, but i doubt it can solve my camber. If the eccentric bolt could adjust far enough then I wouldn't even consider control arms. Adjustables are the only source that can fix my camber...

[SethuM]

pretty simple to do. loosen the diff, you dont need to completely remove it.

[slocar]

yea i know, but i doubt it can solve my camber. If the eccentric bolt could adjust far enough then I wouldn't even consider control arms. Adjustables are the only source that can fix my camber...

See I thought the same thing and now before installing my 3rd set of tires in the last 2 years (keep in mind I only use these in the summer) :eek:, I finally messed with the camber on the stock arms ... well ... I'll be damned if I didn't get at least 2 degrees out of it.

Looking at my car compared to my dad's stock e36, I don't really have any more camber than he does. :/

As silly as it is, try adjusting first: it costs nothing.

[drummerboi]

See I thought the same thing and now before installing my 3rd set of tires in the last 2 years (keep in mind I only use these in the summer) :eek:, I finally messed with the camber on the stock arms ... well ... I'll be damned if I didn't get at least 2 degrees out of it.

Looking at my car compared to my dad's stock e36, I don't really have any more camber than he does. :/

As silly as it is, try adjusting first: it costs nothing.

Honestly, i dont even know how to adjust it. Can you explain in detail how to do it. Do you do it while car is on ground or on jack stands? I already bought the control arm and I just got them today...

The reason why i bought them is because I assume that the tech of align my car couldnt adjust it any more. I think right (if i can recall) now my rear driver is -2.6 and passenger is -3.6. I dont know how or why the tech changed my rear passenger to -3.6, because before that it was about -2.6 like the driver side.

Again, can you enlighten me on how to adjust the rear eccentric bolt. Thanks...

[slocar]

Look where the arm attaches on the end closest to the wheel: loosen the nut on one side and with a wrench turn the bolt ... I did it on a lift because you need some leverage to loosen the nut since it's all corroded after so many years and just watched the wheel in relation to the fender and went as positive as it could then retightened the nuts.

[drummerboi]

Look where the arm attaches on the end closest to the wheel: loosen the nut on one side and with a wrench turn the bolt ... I did it on a lift because you need some leverage to loosen the nut since it's all corroded after so many years and just watched the wheel in relation to the fender and went as positive as it could then retightened the nuts.


Do I remove the nut from the bolt when adjusting the bolt, or just loosen the nut a bit? So by turning the bolt, the wheel will adjust itself? Sorry for the newb questions, I really have no clue when it comes to alignment...

[FCPEuro]

You'd want to just loosen the nut, so there is no clamping force on the balljoint/ salad tong arms. Good luck though. It was to the point that the bolts actually snapped where the nut threads on, causing my left lower arm to snap clean during some hard driving.

I had to mangle the balljoints in the trailing arms on both sides as the bolts were beyond frozen in the balljoints. Replacing those without the BMW tool was not fun, but now I have two new lower balljoints and some nice adjustable arms. After installation (Diff definitely had to move back), I was treated to the fastest and easiest rear alignment ever.

-John

[drummerboi]

When you guys move the diff back or side to side, did you have to unbolt the driveshaft too? Or it can be move without unbolting driveshaft?

[jadidaskv]

left the driveshaft bolted

[FCPEuro]

Don't unbolt the driveshaft, its not necessary. It takes quite a bit of jiggling and pulling to get it to move back far enough. I had a buddy pull the diff back with some tie-down straps wrapped around the output shaft flanges while I wriggled it back and held it up. The joys of working on jackstands....

It will move, just keep trying. Also, make sure you remove all three mounting bolts completely, don't just loosen them.

-John

[drummerboi]

ok thanks guys... My friend just brought over his stock control arms and now I see how the stock arms work. By adjusting the bolt, the arm can move left to right due to odd shape of the bolt's head/washer...

My question is, which way will give the tires negative or positive? If I want more positive camber, should i pull the control arm to the left or to the right (standing behind the car perspective)...

My logic or my understanding is that, if i pull the arm to the left, it would give more positive camber...because the arm is bolted to the bottom half of the tire, so by pulling the arm more left, the upper tire would move toward center... thats my logic... if im wrong, please enlighten me...

As for the adjustable arms, before installing them, how should I set the thread? I have the SPC brand (the cheaper black one), which u can adjust them from both side. Should the thread be set in the middle for both side? How did you set yours FCPGroton?

[slocar]

My question is, which way will give the tires negative or positive? If I want more positive camber, should i pull the control arm to the left or to the right (standing behind the car perspective)...

My logic or my understanding is that, if i pull the arm to the left, it would give more positive camber...because the arm is bolted to the bottom half of the tire, so by pulling the arm more left, the upper tire would move toward center... thats my logic... if im wrong, please enlighten me...



There isn't a one answer fits all ... you effectively want to shorten the arm in order to pull the wheel in (which it will given the arm attaches to the bottom of the wheel). standing behind the car: the left one needs to go right and the right to the left .. .though that's a terrible way to look at it.

[drummerboi]

^ My bad... when I was writing that, in my head, i was thinking of my passenger side only because that side has the worst negative camber... I totally forgot to mention that on the post.. So yes, I understand now... bolt needs to slide inward to shorten the arm...

***Update***
Went to adjust the stock control arm... I decided to set it all the way inward... After putting car back on the ground, tires seem to be straighter with maybe a slight negative... I will drive the car for awhile and let the height sink back in to see how the tire sits...Since i changed the camber, im sure the toe has changed too... I will take it to Firestone (lifetime alignment, but their techs are dumb) maybe tomorrow to see how camber and toe is...

Im just sad that after looking at my tires, the inner is worn pretty bad... you can slightly see the thread... and for some reason, the middle part of the tire is worn more than the inner and outer part...I know that this is due to over inflated tire, but i always inflate the rear to about 36-38psi... This is the second time that the rear tires has worn more on the middle section than inner and outer section...maybe the summer heat is inflating the tire too much...

[drummerboi]

after riding the car for a while, there still seem to be some negative camber... and it seems like there are some toe in... im gonna take it for an alignment soon to see what the numbers are.... im just worry about the thread on the inner...scare that tire might pop any time soon...

[jadidaskv]

get rid of the stockers and put your spc's and get new tires, that tire shouldnt be driven on. it really isnt as hard as it seems to get those things in there. especially after moving the dif around, it not hard at all.

[drummerboi]

just got them on and everything is aligned... car runs straight now...before, it used to pull to the right...

[jadidaskv]

sweet. ya it made a huge difference when i replaced mine, but mine where bent to sh*t when i bought the car. about 1/8" from touching the sway bar lol