Rear Ball Joint Surgery

[TiagE39]

I've done VANOS rebuilds, MID repairs, coding everything, tension struts, thrust arms, struts, driveshafts, cooling system, interior swaps, retrofitting electronics, the lot. I like to think I know my E39's pretty well.

There's one job that still gives me hell: the rear ball joints. Every time I do it, I either end up ready to have a breakdown or about to douse the car in gasoline.

Getting the BJ itself in and out isn't the problem. Have the BavAuto balljoint press and it works brilliantly. Getting the lower arm down to do that isn't hard either.

My problem is the reassembly. The lower arm wants to go up and towards the front and the wheel carrier wants to go down and towards the rear. The net result is that the lower arm (aka swing arm) wants to impale the dustboot on the BJ. I'm not proud to admit that in 3 out of 4 times I've replaced these ball joints I've not been able to avoid damaging the dustboot.

Then after you've got the lower arm fitted over the BJ bore correctly, you can't fit the integral link. There's just not enough room. So you take it apart again and try to fit the integral link as you wrestle the lower arm over the BJ bore.

I've tried disconnecting the swaybar, unlocking the subframe-lower arm bolts, and throwing every prybar I've got at it. Nothing seems to do the trick. It doesn't help that it seems like every guide/youtube video on this repair uses a different strategy (and none of them work for me!).

So tell me, BForums. What am i doing wrong?

[StephenVA]

The issue is the lower swing arm the twists after you remove the long bolts. The challenge is squaring it on reassembly. One of the best methods seems to be unbolting the swing arm open up the area to make it easier to R&R the joint itself the using a long punch to align up all the parts.

[BAM3]

I feel your pain! Just did this for the 2nd time in two years. I talked to a few local BMW mechanics and they all had different advice.

I did it easily this time with a 2nd person, my floor jack, and a piece of wood. I actually bolted up the ball joint and integral link first. I left the rear camber adjustment bolt for last. My brother used the floor jack with a small piece of wood on it to lightly maneuver the rear of the swing arm. I was under the car and pushed the bolt through the forward hole when it finally lined up. I'm know this probably isn't the factory procedure but like you, it saved me from setting the new 540 on fire and filing an insurance claim!

Hope this helps!

Also....I left every nut/bolt on the swingarm very loose until I got the final nut/bolt made.

Sent from my Pixel 3 using Tapatalk

[TiagE39]

@BAM3, I would love to hear more about how you positioned the jack. I've added a jack to this job just about every time, but I always placed it on the wheel carrier to bring it up. Then I would try trapping a block of wood between the arm and the driveshaft to get it to stay down.

[Jason5driver]

LOL, I remember replacing the rear ball joints about 7 years ago .
I took the car to base, and used the auto-shop lift, but I didn't have the correct press tool, just a C-clamp tool, and I ran out of time .
So, I had to put everything back together and do the job all over again.
I was finally able to get the C-clamp tool to fit / work , but it was barely wide enough.
I think it spun the old bolt completely through the bushing ... lol .

[DHoang]

i just did the rear ball joint r&R first time. learned alot about this diy, so.....
next time i do this, i'll follow the fcpeuro method, which like stephenVA posted above, partially disconnects the arm. here's the vid if yall haven't seen it yet . good quality vid,btw

[philly98540]

Great video. That is the way I did it and it works well. One comment, he should have tightened the swing arm bolts at ride height too.