are ball joints replaceable in rear lower swing arm?

[LightlyToasted]

'07 4.8i. Recently refreshed all suspension up front, and shocks and air springs in the rear. Still experiencing some looseness and other handling issues from rear. I'm planning to refresh all control arms, ball joints, and bushings in the rear in the spring.


I can't seem to find any replacement bushings (BMW may call them ball joints) for the inner side of the lower swing arm (part #10 here)


Are those ball joints replaceable separately, or do you need to buy the whole lower swing arm? New ones are very expensive. There's a bit of lateral play in there.

[ard]

You are talking about the two rubber bushings in that large square-ish plate? The inboard side has two rubber bushes, the other part attaches to the wheel with a long bolt?

On the E39 BMW made no replacement bushes...it was a TOTAL pita to find replacements, BMW wanted to sell the whole assembly at $800 per.

Also, if it is the same part I am discussing, it is just a bushing, not a 'ball joint'.

[LightlyToasted]

That's what I feared. If the lower control arm is aluminum, that's probably why BMW doesn't spec replacement bushings. Apparently it's not feasible to press bushings out of aluminum since the steel-shelled bushing will be galvanically welded to the aluminum, and aluminum isn't durable enough to handle pressing a bushing out and back in.


I'll inspect the bushings when I have everything apart. I hope I don't need to buy new control arms.

[ard]

What is the control arm made out of?????


Ive replaced a TON of bushes on BMWs..subframes, diff mounts, etc,etc... all aluminum parts


IMO the reason they dont sell those bushes is that they dont get anywhere near the abuse other bushes get.... food for thought

[LightlyToasted]

The aluminum angle was explained to me by a friend who is a mechanic. I replaced ball joints on E36 front control arms (which were steel), but asked him why no one sold replacement ball joints for the front control arms for my E46 M3. He said it was because the control arms were aluminum, and if the ball joint were pressed out the bore would not be consistent enough to securely hold in a new ball joint. I'm not an engineer, so I have only his word to go by.


I would have to think that the bushings on the X5 rear lower control arm are a standard part. Would love to hear from anyone who has swapped them out.