Rear Ball Joint Replacement (The squeak)

[X5 ALN]

Sorry I never thought to take photo's.

Some basic info - If any one has more, feel free to help out as we have just done one side without releasing the air pressure from the airbag, which made things really difficult to line up, and the long bolt carved a thread in the alloy integral link on the way out due to the load on the arm.  Luckily the threads cleaned up ok.

If anyone can advise on how you refill the airbag after deflating it, it would be much appreciated.  TIS suggests it has to be done with the computer, but surely the car will fill it itself when you replace the fuses?

Identify the fault - In my case, a knock for the last year that could not be found.  I believe it can be found by releasing the air pressure from the airbag - as this releases the load on the ball joint which does a good job of hiding the problem.    I had bought a FEBI kit  (part number 33373 for my car) to do the 4 rear arms, 2  anti roll bar links and 2 ball joints.  as my car has crossed 100,000 I felt there was no harm in changing everything.

We done the ball joints last as they looked the hardest to do.  Changing the 4 arms did not cure my knock.  Between buying the kit and getting round to doing the ball joints my knock turned into an obvious squeak coming from the nearside rear - which gave the confirmation the fault was the ball joint.  There was also rust trace around the ball joint, which must have been coming from inside the ball joint.  On removal, there was a plastic bush separating the inner and outer parts - this was broken and the ball joint surfaces were rusty, with the exception of the area that was making contact metal on metal due to the broken plastic bit.  Pretty obvious it had been destroyed for ages. Now that its changed - the knock / squeak is gone.

If you were only doing the ball joint, I would recommend FEBI part number 34687 which contains the ball joint, integral link that you remove while changing it and new bolts (you do not get the integral link or long bolt included in part number 33373)

The info I have found to do the job properly is as follows (for vehicles with air suspension)

1. Remove the rear wheel

2. Release the air (Fuses are in the rear fuse compartment) - http://tis.bmwcats.com/doc1103606/

3. Remove the stabilizer bar rack mounting (Drop Link) from the rocker arm (Lower Swing Arm) - http://tis.bmwcats.com/doc1056457/

4. Remove the rear shock from the rocker arm - remove the bolt and pull the shock AWAY from the arm - it has a sleeve on the lower bush which locates INTO the arm - hitting it sideways with a hammer coz you think it's seized on could be bad news if you're heavy handed.

5. Remove the lower ball joint - ideally with the correct tool or something that wont mash your alloy Swing Arm - http://tis.bmwcats.com/doc1056462/

Put back together in reverse order.


As mentioned - I have no idea how to fill the air back up, would be grateful if someone in the know can clarify this before I do the other side.

Hopefully this is some help to someone, I should maybe have done this research before doing the job - lesson learned.

FEBI catalogue can be found here - http://www.febi-parts.com/vehicle.php

[Raj]

I've done these too. To deflate the airbag, carefully remove the hose connection off the top of the airbag. Once all done just refit hose (push on and will click into place) and once engine fired up it will re-inflate automatically.

[dirtbiker3]

I too plan to fit a whole rear suspension kit including the rear sub frame bushes as mine are in bits......

Did you replace the nuts / bolts or re-use the old ones? Can you recall any torque settings? Where did you source the lower ball joint removal tool?

Has anyone got a sub frame bush removal tool or ball joint tool living in Norfolk / Suffolk.........