The original rubber bushings (and most bushings of this type) work like this:
The inner metal tube is rigidly clamped. All motion is taken up by
the flexing of the rubber, and the rubber does not slip against
the inner tube or the hole in the A-arm.
Clearly, it has to be this way. If the inner tube were to move against the
mounting
bracket or the retaining bolt, these parts would quickly wear out. If
the rubber rubbed against anything, it would also quickly wear out.
If the poly bushings are too stiff to flex, then clearly they have to
move against something. I guess that having them slide against
the A-arm holes is the lesser evil. It would be quite dangerous for the metal
tube
to rotate on the bolt, since it could quickly wear out and break.
Doug Braun
'72 Spit
At 07:42 PM 11/13/2003 -0600, Larry Vaughan wrote:
>I bought poly bushings, for the a-arms. The metal tube, that fits inside the
>bushings, is 3/16 inch longer than the stock tube in the rubber bushings.
>
>This made me wonder what the bearing surface should be.
>
>The rubber bush is a tight fit and the metal tube will be fixed when the bolt
>is tightened. will the a-arm move on the rubber or the rubber move on the
>metal tube or both.
>
> When I grind the metal tube for the poly bushings, should it be flush with
>the poly bushing when fitted to the a-arm? If not, What gap?
>
> Do I want the metal tube to be the bearing surface? I think so, but I could
>be wrong.
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