A while ago, while my wife was driving my MY2003 E220CDI Avantgarde, the right backwheel seized up and she had to stop the car. After stopping, moving the car was impossible.
The tow car came, and pulled her up on the flatbed. When he delivered the car, the back wheels came free again when rolling backwards, before immediately seizing up again when the car rolled forwards.
My first thought was that something had come loose in the mechanism for the handbrake, maybe I had used too long wheel bolts. So, I started wrenching on it. First I removed the wheel. Nothing suspicious here… (The car has been sitting, hence the rust on the disk…)
Then I proceeded to remove the caliper and the disk to find the problem.
But everything was good. No problems. I actually overhauled this mechanism a couple of years ago.
So, my next thought was that the wheel bearing was gone, so I needed to remove the drive shaft so I could turn the bearing and check if it was a goner or not. I was not able to push the drive shaft in enough to remove it from the hub assembly, so I loosened all the links to the hub assembly apart from the lower control arm.
After this, I was able to push the drive shaft out of the hub and turn the hub to check the bearing. Of course it was ok. No play, no sounds, everything works as it should.
So, my conclusion was then that the problem must be with the differential. Since it is quite a lot of work to remove it, I thought I should check the oil on it first, to see if there was metal fragments in it. This is the oil that came out:
Notice the few black drops in the middle of the drip pan? That is all the oil that came out… So, I guess I found the problem. This means that I will have to change the differential on the car, and probably do a complete overhaul of the back axle as well, since it would be kind of stupid not to do it while taking everything apart anyways.