How do you guys check your REAR ball joints...

[cn90]

Mine is 2006 X5 3.0i 6spMT with 140K miles...


In the video below (air suspension), this youtube fellow had to undo the tension on the REAR suspension to check the REAR ball joint:

https://www.youtube.com/watch?v=b6Pt8NDYWm4


I wonder what you guys do...do you undo the big bolt to the BOTTOM of the rear shock to undo the tension before checking?

When did your REAR ball joint goes bad? In my 1998 528i, the REAR ball joint went south at 120K or so...

[andrewwynn]

For the rear, apparently you can test with spring pressure on but likely only with badly worn. People use different methods to compress the spring to take off tension when not air suspension including creative ways to connect to top of a bottle jack.

I'm about to replace all my back control arms and should have some very helpful details to share. (including the actual reason behind inside tire wear); spoiler alert, not camber.

[upallnight]

Originally Posted by andrewwynn

For the rear, apparently you can test with spring pressure on but likely only with badly worn. People use different methods to compress the spring to take off tension when not air suspension including creative ways to connect to top of a bottle jack.

I'm about to replace all my back control arms and should have some very helpful details to share. (including the actual reason behind inside tire wear); spoiler alert, not camber.

If it is not Camber then it must be TOE.

Edit: Just noticed this is my 7200 posts on this forum.

[oldskewel]

Assuming you've got springs back there ...

Here's a good video discussing the basic problem of how the spring keeps everything under stress, so even loose things feel tight. It also shows the cool screw jack he uses to jack up the spring perch to partially remove the spring's effect to allow diagnosis without disassembly:

https://www.youtube.com/watch?v=_guTE2ANcIg

I saw a guy on here who welded a horizontal bar onto the top of his bottle jack to get the same thing done.

If you have air bags, it's of course much simpler to remove the spring pressure, but even then, I think things can seem tight when they are actually loose.

Me, I could not do any of those, so I took things apart and found the rear ball joints completely shot at around 170k in my 2001 3.0i that has generally been found to be in very good shape. And from the tire receipts the PO gave me, they'd been bad for a while.

When researching things back in the day (soon after getting the car, noticing extreme inner shoulder tire wear on the rears), I also found a really cool youtube video from another BMW. Maybe an E39? The guy had similar extreme tire wear. Mounted a go-pro back near his suspension so he could watch things as he drove. What he found was that when he got on the gas, the completely shot ball joint allowed so much motion of the tire that it was basically burning rubber off the inner edge. Almost like doing a burnout.

Wish I could find that video. Very convincing. So if that's right, it's not necessarily the camber that is the problem, it's the compliance in the suspension that allows it to move when getting on the gas.

[andrewwynn]

Originally Posted by upallnight

If it is not Camber then it must be TOE.

Absolutely. Almost always toe is what kills the rear tires. Usually when a ball joint or bushing fails that allows toe to change under load so it looks ok or even let's you set toe properly. Then under braking acceleration or cornering the toe changes (and apparently almost always toe OUT) to scrub the inisde of the tires.

Here's the evidence to back my understanding:

I have had nearly 3° neg camber for years and able to wear tires to the wear bars the entire width.

Then suddenly a couple months ago I notice inside wear. I figured I have a worn rose bushing or other ball joint but I'll be replacing tires with tax return so I'll last a month or two.

That's a big negative. Tires wore through to the "redneck wear bars" (steel belts) within two weeks. With no measurable change in camber that's been the same for years.

It's not camber.

I will mention I normally take curves at 1/2g. Every time. Maybe 3/4g when feeling a little spirited, so the camber is negated (posated) on the heavily loaded outside wheel.

If you only drive straight and turn at 1/10g, then camber will have more effect on inside wear but still won't be as critical as toe not ever.

Under inflation will have more inside wear effect than camber.

I will show just how bad my toe is affected by the worn parts in the back. I'm about to replace every arm, bushing and ball joint in back. I will be surprised if I can't push the wheel to 1/2 to 3/4° outward toe. (considering spec is 0.15° inside toe that's horrific)

[andrewwynn]

I'm planning to use my fiber optic camera to take video of the motion described above. It will be part of my complete rear suspension overhaul


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[Effduration]

I replaced mine after discovering excessive neg camber (tilting inwards) on my X5 with 100k. I first replaced upper control arm, then did the rear balljoint. I still have neg camber, just not as much.

I have a bottle jack with a 90 degree welded bar (about 10" )on top of it. I had it made for this purpose. As noted elsewhere, I jack up the spring perch (i have coil springs) to relieve pressure on rear wheel knuckle and then see if there is play in the wheel.

got the idea from this forum and the VAC youtube video

[StephenVA]

Guys, at 140K the entire suspension is toast. Not one part but everything that is a wear item front and rear.

If you put in new ball joints with out the upper arms you are tightening one area exposing the slack in all the other parts.

You will need one of these for the lower rear ball joint...

[cn90]

Agree...

But for some reasons, my 2006 X5 has been very solid (bought it at 110K miles). I do not know if the P.O. replaced any suspension components.
They look factory to me.

Somehow the X5 susp parts are very good, more than the E39 1998 528i I have at home. My 2006 X5 with 140K still drives like new, so I am getting older (add "lazy" to the equation lol...), I do not have much incentive to refresh the suspension if I don't have to.

I have done the FRONT and REAR suspension overhauls in my E39 1998 528i, so I am very familiar with it...

Not sure if the torque values are the same as X5, but I will link the DIYs for the 5-series here in case anyone needs them...


FRONT suspension E39 1998 528i:

https://www.bimmerfest.com/threads/d...erhaul.399580/


REAR suspension E39 1998 528i:

https://www.bimmerfest.com/threads/d...erhaul.545345/

[andrewwynn]

My 01 3.0i had worn sub frame bushings when I bought it 68k miles ago. I get the classic double thump on certain conditions but the car handles great just doesn't deal with load transients smoothly (eg reverse to forward or quick power on from stop).

I finally got the bushing tool and bushings as well as the rose bushing tool shown above and will be ordering the complete rear refresh kit today.

I will be taking videos and photos to show each step although per usual I will only show key steps it won't be a cook book recipe, you'll want to watch a YouTube video for the overview.

That said, if camber or toe can't be pulled to spec you have worn bushings and/or ball joints, for certain.

I've helped a few people navigate these waters and the gang that says just do them all is more correct than those that say treat the symptoms as they come.

Caveat: my experience shows that only a couple items up front really mess with toe enough to shred tires and kill responsiveness, so ironically front is less critical.

I have new control arms front and will get new ball joints because I'm sure they are stock but I'll maybe just change the bushings on the tension struts.

At 196k miles, not showing signs of any shock problems so I will wait to see what I find while changing out all the rear parts and front control arms.

Can't wait to have it all tighter.

Anybody that has changed the rear diff mounts have some feedback if it's enough easier to do that with the suspension parts or subframe or can I do that solo after? I'm not sure if the thud from fore/aft power is just the subframe or also dif mounts.