Control arm & ball joint tightening torque

[roxinator]

Forbez how r u doing? Perry here - been a while... I am going to do the same thing to my '04 4.8. Same thing going into parking lots... just a shimmie-shake kinda feel to the rig. Did you run into any problems when doing this?
thx

[ForbesZ]

Hey Perry,

Glad you asked. It was all pretty straight forward except the thrust arm ball joints. Do yourself a favor and replace only the lower control arms and the sway bar links and see if the problem goes away. Those were all fairly straight forward to replace. In general, everything comes apart as you think it should, but when you put it back together, don't tighten the bolts that hold the control arm to the frame of the X until the weight of the car is on the suspension. If you tighten these bolts with the X in the air, there will be preload on the rubber bushings once you put the X back on the ground and the rubber bushings will prematurely fail. The best way to do it is with a pair of ramps.

It was the the thrust arm ball joints that was a huge pain in the butt to remove. You might be able to change the thrust arms without changing their ball joints, but I found that the rubber boots on the ball joints got damaged when I used the ball-joint separator on them.

The problem with the thrust arm ball joints is that the base (I call it the "cup") fits very snugly into a hole in the front spindles, and the back side of the cup is directly exposed to dirt and moisture (you can see it right underneath the CV boot). This is the ball joint that is held in by two 10mm reverse Torx bolts, by the way. The main problem is that after a few years on the road, rust builds up between the cup and the spindle and they become almost fused together. The manual says to remove them with a slide hammer, but that won't do it unless your X has very few miles and hasn't seen any inclement weather. It took me 3 hours per side just to remove these ball joints - I ended up drilling holes in the ball joints and prying them out of their cups with an air chisel. Then I had to use the air chisel to peel the remaining parts of the cup out of the spindle. PB Blaster and WD-40 didn't help at all, even soaking them overnight. I later asked the head mechanic at my dealership about it and he said that almost none of them come out with just a slide hammer. He said they typically have to heat the s*%^ out of them with a torch to get them to budge and occasionally they end up having to replace the whole spindle because it gets messed up trying to remove the ball joint. My way worked all right, but it was a lot of work and very time consuming.

So, if I was doing it again, I would change everything but the thrust arm ball joint and see if that solved the problem. If you do end up changing the thrust arm ball joint, coat the back of the new one with a healty dose of anti-sieze in case you ever need to get them back out again some day.

Good luck!!

[rogerkiu]

According to BMW TIS, the tightening torque for the 2 torx bolts is 60Nm, and 80Nm for the nut, 100Nm for lower control arm to the frame side, 160Nm for the upper control arm to the frame side, all nuts for the rotor side are 80Nm.

[harleyclassic2]

Did anyone ever find out what the torque is on the 2 small torx bolts that hold the ball joint to the knuckle ?

[Clavurion]

Originally Posted by harleyclassic2

Did anyone ever find out what the torque is on the 2 small torx bolts that hold the ball joint to the knuckle ?

60 Nm, like said on the previous post.

[harleyclassic2]

Oh Ok, Thx. I guess I must have somehow jumped in to that thread because I didnt see that answer before (?).

Also why are they called reverse threaded ? Seem to be normal - i.e clockwise tight and anticlockwise loose

[wpoll]

Originally Posted by harleyclassic2

Oh Ok, Thx. I guess I must have somehow jumped in to that thread because I didnt see that answer before (?).

Also why are they called reverse threaded ? Seem to be normal - i.e clockwise tight and anticlockwise loose

They aren't reverse thread - I think the comment was in relation to the Torx head, i.e. normal Torx vs e-Torx.

[harleyclassic2]

Thanks Wayne