Frame / Springs: shackle/rear spring bushings

[junior]

[bezhawk]

The shackle bolts have self locking castle type nuts. There is no washer , the friction against the shackle links helps retain the torque of the fastener and prevents it from rotating.
The inner sleeve is clamped tight, and the outer sleeve is tightly press fit into the spring eye or frame. The only give is the flexing of the rubber. This is also how the front suspension bushing work. That is why it's important NOT to tighten the bolts until the full weight of the car is on the springs. It keeps the rubber from being over flexed and shearing under suspension travel extremes.

[jimmijim8]

Very good Brad. cheers jimmijim

[garyash]

Of course, Studebaker had the answer to this - in 1928! They introduced the Fafnir ball bearing spring shackles, used them through 1933. Rex Miltenberger told me that the ball bearings suffered from "Brinelling" from the impacts of the balls on the races when the cars hit bumps. But, Rex also says that when they are working, especially when they have been re-worked to use needle bearings, that the ride is extremely smooth, even in 1930-ish cars. I haven't found any reference that says that any other car manufacturer ever used them, except Pierce Arrow which was owned by Studebaker back then. I was thinking of writing an article for Turning Wheels or Antique Studebaker Review about these. Any interest?

[DEEPNHOCK]

The Horton Company manufactures a needle bearing spring shackle like you describe...
But it is for heavy trucks.

http://www.hortonww.com/products/products.asp?/en/33/

[junior]

The shackle bolts have self locking castle type nuts. There is no washer , the friction against the shackle links helps retain the torque of the fastener and prevents it from rotating.
The inner sleeve is clamped tight, and the outer sleeve is tightly press fit into the spring eye or frame. The only give is the flexing of the rubber. This is also how the front suspension bushing work. That is why it's important NOT to tighten the bolts until the full weight of the car is on the springs. It keeps the rubber from being over flexed and shearing under suspension travel extremes.

Thanks for the info, now I know...would have been nice if the manual said to tighten the shackle bolts with the weight of the car on the springs...I replaced the bushings when I changed rear axles a few years back and they show signs of shredding. what do you think about the urethane bushings? cheers, Junior

[bezhawk]

The urethane bushings should work fine. If they are the same width. The side to side end play needs to be held to a minimum to prevent rear "steering" when springs deflect over bumps and under torque.

[Xcalibur]

I've used urethane in extreme conditions without a problem. I simply looked around at an off-road business until I found ones that would fit. I grease everything and add grease-zerks where-ever possible. I use self-locking Stover nuts. I use urethane on shackles, anti-sway bar mounts, etc. All the best.