No rust here in California either. Where did you source the ball joints?

Control Arm Ball Joint Replacement
 

Freeze old to remove could help also.

Steel changes size 1% per 100°F approximately so heat the outer part to 250F or so and cool the inner part to -15°F (use R134a aka canned duster).

I've measured 0.003" (0.08mm) difference in my front bearings.

Don't make the goof of freezing rear bearings on X5: oops they are bolt on but press over the hub: cold makes them tighter.

I made a kit from an R134a can valve and a shop air duster to apply cold to things. Originally so I could freeze a water pipe to change a valve downstream. I've done that a couple times.

I've used dry ice to cool a hub to remove from my front bearing but now I just needed up my bearing press to 31T capability no longer need to use heat and cold.

I got Delphi branded ball joints. Got them from rockauto. I can't remember how much I paid...def not the cheapest and decided to go with something name brand.

Thanks. Were they specified as being for the BMW control arms or are they sold by size?

I'm not sure I exactly understand your question. They're the rear lower ball joint. Rockauto has these in a weird spot for some reason.

This is what I bought:

This discussion started off being about the lower rear FRONT arm ball joint...

https://3a663eb0fef48c6d2d60-a88f8eb...79106_x600.jpg

...but it's gone a little off track due to unclear terminology around the various arms... ;)

WTF Need clarification
 

This will make the conversation MUCH easier as everyone will actually know what the hell they are specifically discussing.:dunno:
FRONT Suspension Parts
REAR Suspension Parts
The Front Suspension has multiple "Ball Joints" some are attached to the arms, others are separate parts. The front also has BUSHINGS that are part of two arms.
The REAR Suspension has a BIG Ball Joint on the LOWER part of the hub/wheel Carrier that attaches to the lower swing arm and all X5s has few little ones in the UPPER arms that are part of the control arms (entire arm is REPLACEABLE) See Images below for details.

Now that we are shop class 101, point to the image and give us the number of said part that you are all replacing....:thumbup:

I am talking specifically about the ball joints located IN the front lower control arms, the rear front control arm and the rear, rear control arm (sometimes called the wishbone). These control arms come with the ball joints installed IN them. For example, the ball joint in item 6 in your diagram. I am NOT talking about the ball joint that mounts to the steering knuckle or the ball joint that goes in the rear wheel carrier. The ball joints IN the control arms I'm asking about do not show as separate parts on RealOEM.

My question is/was if anyone has replaced the ball joints that come IN the control arms.

I hope that makes it clearer. Sorry for any confusion.

Item #6 in the rear suspension forward control arm (Upper Guide Link) has a small swivel joint (ball shaped) that only comes with the arm. Their average life span is 100K, so one replacement in 200K for the 3.0 applications, longer than most owners' ownership. In the large V8 they last approx 60K depending on driver and road conditions.

Unless your needs are such and you plan on HEAVY modifications, it works as designed.

The next question just for curiosity, Why would you want to? What performance, adjustment advantage are you seeking?

There was a company that made adjustable length units many years ago. Are they still around? Who knows. Use the search function on this site to find the postings.

I'm interested because I will be changing the bushing to poly which is essentially a lifetime bushing. So the ball joint is likely to wear out before the poly if the poly ever does. The existing arms have about 60,000 miles on them, so they've got maybe 40,000 miles left in them. I have 250,000 miles on this truck and I am shooting for 350,000. That means those ball joints will need to be replaced sometime before I ever have to replace the bushing. Since the arms themselves are essentially a lifetime part and a poly bushing is a lifetime part I'm curious to know if it is possible to replace the one piece of the arm assembly that's not lifetime. Especially since if the ball joint can't be replaced I will need to order a complete new arm, press out the rubber bushing to install poly and throw away the rubber bushing. Along with throwing away a perfectly good control arm that comes off with the worn out ball joint. Make sense?

Adjustable are still available from Hardrace: https://hardraceusa.com/collections/x5-e53-2000-2006