bumper falling off 123
 

the rubber bumper pad attached to the rear bumper of my 83 240d
has been slowly separaring from the bumper. no big deal. yesterday i
noticed that the pad had pulled a little farther away from the bumper.
looked closely at the situation. the bumper itself is now separating from the
car on the right side. as near as i can tell the bumper is glued to the
telescopic struts that are bolted to the car. is this indeed the
case? how does one reattach the bumper to the strut? damn, i would
have thought that the the bumper would have been secured by some
type of mechnical fastener. thank you.

janko,

The bumper is attached with mechanical devices. On my 1982 240D the rear bumper is an aluminum casting with some mechanical mounting clips cast into the inner surface of the bumper. These clips fit the heads of the bumper shocks, kind of like a "T-slot" arrangement. The mounting sequence is to put the bumper shocks into the clips, then run the shock tubes into the recesses in the frame, and bolt up the flanges. Once the tubes of the shocks are in the recesses, the bumper cannot disengage the clips. Older cars have a different clip arrangement, which I believe involves bolting the clip hardware to the bumper.

When the bumper gets old and the aluminum gives way to corrosion (the inside of the bumper is a place where no one usually washes, and sand with road salt collects by the pound there, leading to this problem. On the driver's side, the hot exhaust usually accelerates the process.) the clips begin to rot away. Once they are gone far enough to let the bumper begin to fall off, the solution is to either buy a used bumper from a car down south, or fabricate a new clip arrangement and bolt it into position. You may be able to convert to the older style clips, but I am not sure about that. I know I fabbed some new clips and bolted right through the bumper. This lasted for another 5 years or more, but eventually the aluminum began to crack at the bolt holes. My daughter replaced the bumper with one from another junked car at the college auto club (a W123 Diesel fanatic there donated it to her cause as the school told him to have the car towed to a junk yard or else...) a year or so ago, and that bumper is working fine. I think it has the old style clips, but I have not checked.

Good luck, and I hope this helps. Jim

bumper glue failure
 

happened to mine. used coat hangers at the corners - thread through between the bumper and the rubber, around the bumper to conveniently placed holes attached to the body. does the job and does not look too bad until can find some type of super glue to use on the inside or some other method (drilling though bumper so to bolt onto the bumper mounting struts??)
realize the above jury rig is not the greatest but at least am confident i won't see the whole bumper falling off on the highway behind me:eek:

I believe that the 1977-1981 (W123) chassis had a slide on shock absorber and the 1982-1985 (W123) had a bolt on shock. Both of which are changable. You basically have to remove the 17mm nuts that retain the shocks to the car. Once you have removed the bumper you can determine which style you need to get.