I had the pleasure of working with club member, Steve Arnold, to remove and replace the rear suspension trailing arms in his ’68 Corvette. The trailing arms are left and right side suspension components that link the chassis to the rear wheels. They transmit all of the accel and decel forces from the rear wheels to the chassis. The trailing arms also house the rear spindle bearings that support the weight of the car plus all the dynamic forces. After 57 years, Steve rightly worried that the bearings were worn and the lubricating grease dried out.
Compared to most muscle cars of the time, the C2 (’63-’67) and near-identical C3 (’68-’82) rear suspension is more complex. It provides better traction and a potential for a better ride than the ‘solid’ rear axles used in almost all other American cars of the time. But it is less understood and more difficult to work on.
Before Steve started taking things apart, he did a great job making clear sketches and noting-down measurements of the pertinent spacer shim thicknesses and alignment settings (yes, the Corvette rear suspension needs to be ‘aligned’).
Steve’s Corvette is in good condition underneath with far less corrosion than most, and apparently had previous updates, so disassembly was a lot easier and cleaner than many old Corvettes I’ve worked on…. Until it was time to remove the trailing arms at their pivot bolt.
The pivot bolt is typically rusted to the steel inner sleeves of the rubber pivot bushing. We got the castellated nuts off the bolts easily enough, but the bolts could not be pounded out. So, it was time to give the reciprocating saw a workout. It got workout all right, and so did two ‘older’ guys, over two work sessions. What a noisy, shaking, arm-numbing work out! We had to saw through not only the bolt (at two places alongside each trailing arm) but also the much wider, rusty shims that were not slotted and so would not come out either. Chevy switched to slotted shims a year or two later. Too bad for Steve and me.
But, we got it done. You can see a happy Steve posed with the two removed trailing arms, looking sort of like a proud fisherman holding the two prize fish he’d just caught. Well, that’s how I saw it. And I’d rather work on an old Corvette, than go fishing. But that’s just me, I guess.
One arm’s spindle bearing seemed snug and OK, the other had some end play and rotated with some slight roughness.
We also peered inside the rear differential housing though the fill hole to check that the cross shaft retaining bolt was intact. It was, and the gear oil we suctioned out seemed clean and reasonably free of debris. Steve replaced the gear oil with genuine GM posi fluid which includes an expensive additive to reduce/prevent shuddering/chattering/thumping of the posi unit in tight turns.
Steve sent the trailing arms off to Bair Corvette in PA. Bair’s does suspension and chassis rebuild and restoration work on old Corvettes and was recommended to us by both my old friend and longtime Corvette owner/restorer, Butch Schroeder, and also by a guy from NCRS.
Steve ended up driving to Bair’s on a snowy Saturday, getting a tour, picked up a set of new trailing arms with all new components (they might have re-used the spindles) – his original trailing arms were deemed too rusty to re-use, and he drove home: all in one l-o-n-g day.
Bair also suggested he switch to the later-type slotted pivot-end shims, so the next caretaker of his Corvette would not have to saw them out like we did in, say 2085. Ha ha. Well, it would also make swapping shims in and out easier now, in 2025, if the rear toe-in needed a reset once we reassembled everything.
I helped Steve get the trailing arms back in the car, and then he did all the remaining reassembly. Then I came back to help reinstall the rear calipers and bleed the brakes.
We took the car for a careful test drive on a nice Spring day and all went well. Plus,Steve was hugely relieved that the tach and speedo he replaced worked properly. He had really suffered taking the dash out to replacing these instruments. And uh, it wasn’t long before I found out for myself not too many weeks later, what a miserable job that was while helping another club member with his ’75 Corvette.
But I like working on old cars! And working with our club members!
