This is to warn W123 Mercedes 240D and 300D owners about the possible shearing of rivets on the window regulator mechanism after 300,000 to 400,000 miles . (the black arrows in the pictures point to the rivet/rivet hole locations) This rivet failure will render the lowering and raising of the window impossible. When these rivets sheer, the window up/down button will have no effect although you will hear the motor run.
The door panel must be removed and the entire window regulator, including the motor, must be extricated while leaving the window glass remaining in the door.
After removal of the window regulator mechanism, mount it in a vise
The old rivets must be drilled out. I used a 5/16" Tap and a #10 drill to thread the resulting hole to allow use of two new carbon steel bolts in place of the rivets. I then ground the bolts heads down so that they would clear the gear. I tack welded after that to add further strength.
Number of hours labor involved is minimum 3 to 4

Nice write up!
This still looks way more heavy duty than what you'd find in the newer models. The 124 models have a POS cable and pulley set up. Tiny little motor to boot. It only takes about a 1/2 hour to R&R it though.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

That's a nice repair. All the window mechanism failures I've seen (and I've replaced 3 of 4) have been frame cracks that warp the mechanism gear away from the motor. Not repairable.

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'83 240D with 617.952 and 2.88
'01 VW Beetle TDI
'05 Jeep Liberty CRD
'89 Toyota 4x4, needs 2L-T
'78 280Z with L28ET - 12.86@110
Oil Burner Kartel #35

http://i16.photobucket.com/albums/b1...oD/bioclip.jpg

good thing it's not a Chevy...mt grandfather loves his Chevys and we find that all of them at about 80k break a window rivet....

warp i have seen more than anything as well...

good repair!
Jake

I removed my non-op regulator today and remembered this post. I found that the rivets had sheered in half and I was able to punch them out without drilling. The resulting hole is something like .245 inch. I used 1/4in rolled pins and tapped them in place. Do not tap them too far down, just flush. It is much easier to get them to go down, not so easy to get them back. I tack welded them in place, but I think you could get by without doing this. Cost of repair $.80.