[Needbmwpartzz]

Hey everyone.....just ordered a control arm kit(tension struts with bushing,ball joints and upper control arms)
I have searched for upper control arm DIY but can't confirm that it's as easy to replace as the Lower tension Strut,
Anyone can point me in right direction or walk me through it?
thx!

[Efthreeoh]

It's just a "control arm" and really called a "wishbone" (15). It is the lateral link that mounts from the subframe out to the bottom of the steering knuckle. The tension strut on the Xi is called a traction strut (8) and mounts the the rear of the steering knuckle to the rear of the subframe.

[Needbmwpartzz]

Originally Posted by Efthreeoh

It's just a "control arm" and really called a "wishbone" (15). It is the lateral link that mounts from the subframe out to the bottom of the steering knuckle. The tension strut on the Xi is called a traction strut (8) and mounts the the rear of the steering knuckle to the rear of the subframe.

That"wish bone"is what I got with the kit...just a bolt/nut at one end and nut/ball joint on the other.
Can this be easily removed/installed just like the traction strut or is there a special procedure?

[Efthreeoh]

The ball joint stem should have a Torx fitting so you need a Torx socket. I don't know the size because have air tools (I'll guess a T45). The bushing bolt is just a bolt. The suspension needs to be loaded when torquing the bolt. Put a jack under the rotor and compress the suspension (but not enough to take the car off the stands under the lifting point).

[Needbmwpartzz]

Originally Posted by Efthreeoh

The ball joint stem should have a Torx fitting so you need a Torx socket. I don't know the size because have air tools (I'll guess a T45). The bushing bolt is just a bolt. The suspension needs to be loaded when torquing the bolt. Put a jack under the rotor and compress the suspension (but not enough to take the car off the stands under the lifting point).

Gotcha....I knew I bought torx socket set for something.
So your saying I should not tighten the bushing bolts on both tension strut and wishbone until I preload suspension first?
TIA

[PhaseP]

Originally Posted by Needbmwpartzz

That"wish bone"is what I got with the kit...just a bolt/nut at one end and nut/ball joint on the other.
Can this be easily removed/installed just like the traction strut or is there a special procedure?

You didn't find any diy on this one because it doesn't seem to wear on XI, and there is no M3 version to replace just for performance.

The issue you will run into replacing it will be the nut on the steering knuckle. It is positioned just under the CV axle outer joint boot, and with it there you cannot put a socket on it, yet alone a torx/allen whatever is needed to stop the ball/joint strut from turning. If you remove the axle from the spindle than it will be easy access to the nut and the ball joint. Removing the axle can be problematic if it is rusted there.
If your remove the axle from spindle you will need a new axle nut. The torque spec on the axle nut on this car is a very high number, don't remember exactly but could be around 300 ft lbs. You would need an impact wrench.

The other arm is replaced more often because of the hydro (oil filled) bushing cracks and leaks its oil.

Someone had reported that they had been able to remove and replace without removing the axle with a box wrench or crescent. I think it is a 24 mm nut, because others are all 24mm.

[PhaseP]

Originally Posted by Needbmwpartzz

Gotcha....I knew I bought torx socket set for something.
So your saying I should not tighten the bushing bolts on both tension strut and wishbone until I preload suspension first?
TIA

The wishbone has a spherical ball joint on XI's, I think, you can verify yourself. If inside is rotating wrt to the arm without limit than it is. And if so, it doesn't need preload of the suspension.

The tension (compression on XI) strut has rubber bushing and so needs preloading the suspension, so that when vehicle is on ground it won't be twisted all the time causing premature wear.

I think the best and accurate way to load the suspension is to measure the ride height when vehicle is on flat ground from fender to center of the wheel and note this length. Then jack up the spindle from under the control arm with a block of wood to bring the center of the hub to same distance to the fender.

For loading the suspension some DIY's show jacking from under the hub (rotor hub) but I found that to be dangerous because wheel tends to rotate as being jacked up from there, and so can slip off of the jack.

[Needbmwpartzz]

Originally Posted by PhaseP

The wishbone has a spherical ball joint on XI's, I think, you can verify yourself. If inside is rotating wrt to the arm without limit than it is. And if so, it doesn't need preload of the suspension.

The tension (compression on XI) strut has rubber bushing and so needs preloading the suspension, so that when vehicle is on ground it won't be twisted all the time causing premature wear.

I think the best and accurate way to load the suspension is to measure the ride height when vehicle is on flat ground from fender to center of the wheel and note this length. Then jack up the spindle from under the control arm with a block of wood to bring the center of the hub to same distance to the fender.

For loading the suspension some DIY's show jacking from under the hub (rotor hub) but I found that to be dangerous because wheel tends to rotate as being jacked up from there, and so can slip off of the jack.

Thanks for the tips...I will keep these in mind....especially the jacking of suspension safely.
Seems the xi is a little more complicated than the i.

[PhaseP]

I should be more accurate, rereading what I wrote. What I meant below was to lift it under the control arm's ball joint at the spindle, with a block of wood. Not just under the arm, don't want to bend the arm.

Then jack up the spindle from under the control arm with a block of wood to bring

[Needbmwpartzz]

Originally Posted by PhaseP

I should be more accurate, rereading what I wrote. What I meant below was to lift it under the control arm's ball joint at the spindle, with a block of wood. Not just under the arm, don't want to bend the arm.

Haha....understood and thanks for clarifying

[Needbmwpartzz]

Anyone know if the ball joint on tension strut needs a T47 or T50....I just found out my set only goes to T45 and no go!

[PhaseP]

T40, I broke one so that is how I know.

[Needbmwpartzz]

Originally Posted by PhaseP

T40, I broke one so that is how I know.

It's the ball joint on the ball on the end of tension strut that's has two torx bolts holding it onto(for lack of correct word,spindle or knuckle)of the xi...it's bigger Torx bit.

[PhaseP]

I thought you were asking the torx needed to stop the ball joint strut from turning while tightening or loosening the nut on the ball joint.

I guess you are asking about two torx bolts that bolt up the ball joint itself to the spindle? I don't know those, didn't replace them.

I read if it is rusty it is a bear to remove that ball joint from its hole on the spindle. There was some thread about it.

[Needbmwpartzz]

Originally Posted by PhaseP

I thought you were asking the torx needed to stop the ball joint strut from turning while tightening or loosening the nut on the ball joint.

I guess you are asking about two torx bolts that bolt up the ball joint itself to the spindle? I don't know those, didn't replace them.

I read if it is rusty it is a bear to remove that ball joint from its hole on the spindle. There was some thread about it.

Yup the two bolts.
Is there a special tool to pull it out?

[PhaseP]

No special tool, you just need to hammer it down from above after taking out the torx bolts. A lot of good quality penetrating oil, don't be afraid to adding the penetrating oil repeatedly after you work on it. You may even need to heat it. I suggest hitting with a hammer on a socket that fits in the hole so that you push on the outer case of the ball joint, not the ball inside. That could make it easier, maybe. My theory hitting the center would drive the ball down and that would be expanding the outer shell of the ball joint making it more difficult to push out. I don't have first hand experience though. One other thing if I were to tackle this that comes to my mind is to hit on the flange where the torx bolt go through, after removing the bolts, with a punch/drift to make it rotate a bit back and forth, so that the rust and corrosion breaks free. Then hit from top to drive it out.

If you were to remove the spindle all together you could use a press to press it out I guess.

An air impact hammer would be nice. Air tools overall make suspension job much easier.

Also to separate the arm from the ball joint, you hit where the ball joint goes through the arm with a heavy hammer while pushing down with a pry bar. Eventually pops out. Some people use ball joint separator, or maybe pitman arm puller for this.

Patience, penetrating oil, impact (either manual hits with hammer, or impact tools) gets the result in my experience.

[Needbmwpartzz]

Originally Posted by PhaseP

No special tool, you just need to hammer it down from above after taking out the torx bolts. A lot of good quality penetrating oil, don't be afraid to adding the penetrating oil repeatedly after you work on it. You may even need to heat it. I suggest hitting with a hammer on a socket that fits in the hole so that you push on the outer case of the ball joint, not the ball inside. That could make it easier, maybe. My theory hitting the center would drive the ball down and that would be expanding the outer shell of the ball joint making it more difficult to push out. I don't have first hand experience though. One other thing if I were to tackle this that comes to my mind is to hit on the flange where the torx bolt go through, after removing the bolts, with a punch/drift to make it rotate a bit back and forth, so that the rust and corrosion breaks free. Then hit from top to drive it out.

If you were to remove the spindle all together you could use a press to press it out I guess.

An air impact hammer would be nice. Air tools overall make suspension job much easier.

Also to separate the arm from the ball joint, you hit where the ball joint goes through the arm with a heavy hammer while pushing down with a pry bar. Eventually pops out. Some people use ball joint separator, or maybe pitman arm puller for this.

Patience, penetrating oil, impact (either manual hits with hammer, or impact tools) gets the result in my experience.

Good advice....I like the idea of loosening it by chiseling the ears where the bolts go through then hammering from top.
I will be attempting this soon.....just gathering some more tools and know how here first....got all parts in hand.
Guess I won't know what I'm fully getting into until things are apart.
Surprised there is no puller or something that easily just takes this out......as I know the space is limited because of the drive axle.