The front left (right hand drive) of my 2005 e350 has developed a wee squeak on up and down bumps, in the last 2 weeks it's become quite a bit worse and has turned into a much louder squeak - like a bad old bed.
Here is a video of it while I've got it going up and down on a jack so you can hear it: While you won't be able to tell in the video the noise is coming from the hub area, there's no noise coming from within the strut tower, the shocks or the upper control arms.
So far I have replaced the lower control arm and ball joint, lubed all the bushings (without removing any rubber boots) and I've also removed the brake pads to see if the noise was caused by anything in there - no luck.
Anyone got any ideas as to what I should do next?

I wouldn't be surprised if it is the swaybar body-side mounts.

Are you referring to these?

Yes, if you have 4matic. Looks a bit different for RWD versions but same idea.
They cause all sorts of weird sounds and seem to be missed by people diagnosing noises.

Thanks! I am going to try lube up one more ball joint by the hub and see if that does anything - then I'll turn my attention to this.

Right the last diagnosis worked. I punched a hole in the other ball joint at the hub (not the lower control arm, the other one) and sprayed it with lube. The squeak has temporarily gone.
I'll order the ball joint and replace it!
Yahoo!
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