The Corvair swing axle setup doesn't tuck under. I know this because I duplicated the exact conditions that should have killed me and my passsengers when my severly overloaded Tempest station wagon's brakes failed going down a steep mountain road, brought the rear end around, yet I was able to keep it under control. Hence, we're all still alive. Like a Porsche 911, except that car didn't draw Ralph Nader's ire... the swing axle Beetles were actually far more dangerous in corners, yet all Nader had to say about them was how well built they were. Yes, I read 'Unsafe At Any Speed' in its entirety.
Anyway, the '63 Tempest IRS was the first thing GM ever designed with the help of a computer, and you can see its DNA in subsequent GM independent suspensions. Conceptually similar, yet significantly different from the Corvair control arms used in earlier Tempests. The Corvair relied on a spherangular bearing with barrel shaped rollers so the control arm pivoted on a shorter radius than the axles. The '63 Tempest IRS had axle bearings that didn't pivot, they're just great big regular ball bearings.
Back to the suspension at hand, yes I knew there were U joints on the outsides, contained within those big alloy balls. It's also obvious why they put the brakes inboard, as there's no way for the suspension to handle any twist from regular outboard brakes. Back when I was a mechanic, I recall not being hyped on that design.. :-D in terms of having to dismantle it to do the brakes.
Last edited by Tronman; 02/18/2026 10:04 PM.
