What's up with control arm shafts?

[CastIron]

I can't seem to find any good information about servicing the original style control arm shafts. It looks like they don't use rubber bushings. Does that mean they are all metal? And is there an advantage to updating to the 73-up style arms?

[Redline novdog]

Yes all metal. I had to replace the drivers side a-arm because the shaft ate through it. Bought a used a-arm and new shaft. I bought the shaft and end nuts from Napa here in town

[Pythonater]

These older shaft designs are unique in that the shafts and bushings are "threaded" together. The shafts are U-bolted to the cross member while the bushing ends are fit through the control arms and threaded onto the shaft ends. As the suspension oscillates the control arms (bushings) rotate on the shaft threads, hense why each of the shaft bushings were fitted from the factory with grease zerks. If they are not greased they will eventually wear and cause many alignment, steering and handling problems. One might consider the firmness of this setup as a handling bonus since there is virtually NO discernible movement in these bushings when in new condition. The newer style rubber bushed A-arms will provide a softer ride, but deflection in the rubber bushings can affect handling.

[SCOTI]

Think of this arrangement as 'prehistoric Delrin' bushings

The 'bushings' don't flex & simply pivot. The quality difference is that as stated if the maintenance service frequency isn't/wasn't maintained, it was common to wear through causing issues.

[CastIron]

Thanks for all the replies. I'm going to be doing a disc brake conversion and was wondering if I should change it to the newer suspension. I'll think I'll stick with what I've got.