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Discussion Starter #1
I'm replacing the rear upper control arms on both sides. Wishbone #18 and Guide Link #14 here RealOEM.com   BMW E39 M5 REAR AXLE SUPPORT/WHEEL SUSPENSION

The Wishbone #18 is no problem, easy-peasy. Getting the eccentric bolt #15 out from the guide link #14 has been impossible so far on either driver of passenger side. The bolt seems to be bonded to the inside of the bushing bore. With the nut and eccentric washer #16 and #17 off, the bolt can not be turned inside the bushing and I haven't been able to figure out a way to draw the bolt out. From what I can tell, once loose, the bolt should turn freely inside the bushing. That is how the eccentric moves the arm to set the Toe, right?

Anyone have any experience with this? It is soaking in Kroil at the moment. I've had an 18" breaker bar on it and it won't budge. The bushing in the arm rotates with it and it doesn't move freely. Seem like the eccentric range of rotation is limited?? I'm a bit hesitant to put more pressure on it for fear of damaging the ears where it mounts on the subframe. As last resort I'll cut through the bushing and eccentric but I really don't want to do that. The Russian TIS is not much help and nor were the videos I found.
 

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The bolt and the bushing are likely seized. The penetrating oil along with heat may free it up; but in all likelihood, you will end up having to cut the busing and perhaps the bolt to remove the control arm. A coating of anti-seize in the bushing will help prevent this from reoccurring.

Good luck.
 

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Yup, just did this last week on my buddy's E39 wagon. Break out the sawzall and do work...... You will have to cut both sides of the bushing/bolt to get it out. Be careful not to cut the actual frame. I use the Fire/Rescue blades when cutting. They make short work of just about anything.
 

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Acid will work better than penetrating oil. Vinegar is too weak. Household descalers should work if you can get it in. I freed one with that but the bolt was bad enough to warrant replacement anyway. The other side I did not bother and cut out with a grinder and zip blade.
 

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Discussion Starter #5
Thanks all for the replies. Confirms what I am experiencing. I was worried I was seriously missing out on a step somewhere. Hopefully the dealer will have this relatively cheap part in stock so I don't have to order it in and wait. I really thought I was going to be done with the suspension refurb this weekend, but the car has been fighting me every step of the way.

I'm definitely going to do a post mortem on the eccentric. Going from the pic on ECS tuning of the part, I'm struggling to see how the steel bolt is locking onto the aluminum bushing given that most of the shaft is stepped down quite a bit from the bore diameter of the bushing. Not the way I expected it to look.

Also....I was surprised how springy the subframe mount for this control arm is. I'm sure is it more stable when the bolt is torqued up, but I think I would spend some effort boxing that in before I sprung for a rear shock tower brace........
 

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I can tell you what I found in mine. It was the same crud I found in the abs sensors in the back. It is like a white scale that is firm when in place but quickly turns to fine power. It seems to grow because it crushed my ABS sensors until they died. Every time I find this stuff I find little to no sign of pitting or signs that this is from corroding metal. I only see it where aluminum is, more often on cast.
I suspect it is something left over from road salt, but the stuff does not taste salty but it does have a bite to it like it is super basic. I know dumb tasting an unknown, but... lets just say I understand how curiosity killed the cat.
I will be curious what you find, you mention they use a ton of salt on your roads, do they use the liquid too? I see it on ramps.
 

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Discussion Starter #7
Sailor,
Last year they were all giddy in MKE that they were able to reuse salt brine from processing cheese, on the roads. :3::grrrr:
I applaud your pluck for tasting the offending material, but I'm not going there.:).
I'll post pics of anything interesting. To be fair, these parts do have 15 years on them...
 

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I concur with salt.

My suspension on the rear was also covered in similar powdered "scale" on removal and my front suspension pinch bolt was a PITA to remove because of the same substance. Roads are heavily salted here in the UK and that's evident of the same scale I see on all of my rear suspension every time I remove a wheel and onspect
 
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