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Reply to "stubborn lower-rear control arm bolt"

Somewhat off-subject to the stuck bolt, but the upright sleeve pivots in two bronze bushings and should be a fairly tight fit there. Bushing wear can give odd handling and even clunking noises as the spacer moves up/down under load. The rest of the assembly is a slip-fit.

The problem is, the spacer is made of hardened high-carbon steel which is very succeptable to rust. And the upright as designed was intended to have the bushings periodically hand-greased during disassembly. So the whole cavity in which the spacer runs is dry, gets no service and collects condensation, then rusts solidly to the long stud. This was so prevalent early-on, Hall Pantera started offering a kit of parts to replace those destroyed by sawing the ends of the stud off. Sometimes, the rusted stud was so tightly bound up, it broke or the end of the a-arm tore loose, collapsing the suspension on that side. I saw this happen at a speed event in the early '80s. It took some work to even get the car onto a tow-truck without body damage.

There are various fixes involving zerk fittings in different locations on the uprights. Trouble there is, the grease needs to get inside the spacer where the stud is, as well as on the outside to reach the bushings. Hall sells a custom lower stud kit with zerks in each end; the stud-ends are each drilled about 3" deep for internal grease passages that come out in the middle of the spacer. There also needs to be a matching hole drilled in the middle of the hardened spacer and a couple of notches filed in each end of the spacer, so grease can also get from the drilled stud to the two bronze bushings more easily. I did all this to our uprights and also changed the spacers to 321-stainless steel: no rust. After a decade, no trouble. A recommended mod for all Panteras.
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