C2 rearend configuration

[Steve D.]

With the chassis reassembled and on jackstands, the half-shafts hang at a fairly high angle. In this position the spindles will not turn a full 360 degrees due to binding in the half-shaft joints. Is this normal?

Steve

[Michael H.]

Re: C2 rearend configuration

Steve,

I don't know if this is still true today but years ago, Paul Adams told me that the only shock absorbers that limted the control arm travel enough to eliminate that problem were the original equipment shocks. He said everything aftermarket and even some of the newer Delco parts were longer and allowed the arm to move down far enough to cause this binding peoblem.

I've never really looked into this or experimented but I bet he's correct.

Michael

[Duke W.]

Re: C2 rearend configuration

What model year?

There are at least three different axle shaft end yokes. For sure the first design ('63 only) allow yoke end interference with the axle flanges at full rebound.

I know the third design does not, not sure about the second design.

I consider this to be a DESIGN ERROR with safety implications, and I replaced the originals on my SWC with the latest design to eliminate the interference.

Duke

[Joe L.]

Re: C2 rearend configuration

Duke-----

Yes, the "1st design" 1/2 shaft u-joint flange (1963-only) was a nodular iron CASTING. The "2nd design" (64-74) was a steel FORGING manufactured in-house by GM. The "3rd design" (75-79) was a Dana-manufactured FORGING. All are functionally interchangeable and each superceded the earlier for SERVICE. The forged pieces had a significantly thinner cross section than the 63-only casting. The last part, GM #360913, is still available from GM and also from many Dana-Spicer dealers.

Any of the above will usually interfere when the rear suspension is at at full deflection as occurs with the rear of the car jacked-up off the ground. Of course, the "1st design" is the worst for this due to its thicker cross section. However, I doubt that the sort of suspension deflection as occurs with the car jacked up would ever occur during normal driving. Such a happenstance might be possible with the "1st design" flange, though.

I do not recommend operating the rear drive under power with the suspension off the ground unless the rear suspension is supported at the shock mounts in such a manner that the flange interference is eliminated. As a matter of fact, it's really not a good idea to operate the rear drive under power unless the rear suspension is supported at near-normalized configuration.

I don't think that turning the rear drive manually, even at full suspension deflection with flange interference, will harm anything, though. Usually, one is not going to manually turn the drive over very many revolutions, anyway.