On a 1989 420SEL, 290K KM, I would like to replace the lower control arm, rear bushing, which connects it to the frame. The clip on the nut, inside the frame, has rusted off, so I cannot hold the nut in place as I turn the bolt from the bottom, the bolt and nut just spin. I cannot get an open wrench into the hole to hold the nut. The front bushing bolt and nut are in the same condition. Do you have any recommendations as to how to get the bolt and bushing out?

Also the mount seems heavily rusted. Does anyone know if it is possible to buy a new prefabricated mount? Or do I have to get a portable welder into the repair shop to custom fabricate and weld on some new metal? If so, what should be the specifications for the steel? How thick should the steel be?



Attached is a photo of the situation.

Attached Thumbnails

 

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1989 420 SEL

Scary!!!

Aren't those nuts removable? On my 300sd they are. When you buy the new parts it should come with new ones. I dont think there are any no replaceable captive nuts in the whole front suspension.

Yes, the nuts are supposed to be removable, but the wings on the nut, which prevent the nut from turning, have rusted off. The hole, where the wings extend, are too small for an open ended wrench to enter. So now the nut, inside the frame, turns as I turn the bolt from the bottom.

Yes I do have a new nut and a new bolt to replace the existing ones.

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1989 420 SEL

300SD Rust Restoration Project #2

300SD Rust Restoration Project

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