On front spring perches, there is a tapered shoulder on the bolt at the top and a cone washer on the bottom. Why is that?
It's the only way to keep the perch bolt tight with all the forces on it. Just like cones on a lug nut.
Can I steal your phrase "Just like cones on a lug nut"? Seems I know some lug nuts without cones, hmmm...
The taper of the top of the perch and the nut on the bottom fit into the matching taper of the wishbone knuckles and keep the wishbone solidly centered and in position on the axle. This solid style of mounting eliminates wear unless the perch nut is loose or the perch has been bent and stretched so slop is possible.
Yes, exactly. Think about a simple straight bolt being strongly shoved laterally with spring movent and getting multiple fore&aft forces when brakes are applied...it would not last long. Bolts are not right for properly designed locating and lateral force situations, which as why there are so many dowel pinned or otherwise designed locating systems on critical bolted parts. The cones have much the same function, to solidly locate and to resist forces not controllable by the linear clamping that bolts do.
guessing you have aftermarket perch pins (bolts) you can replace the coned washers on the bottom with the correct tapered nut. cheap,$5.00 pr ??
Why is it, do you think, that the makers of the new perches don't make their own correct tapered castellated perch nuts or simply supply new ones from theanttique parts market with their perches rather than sending a tapered WASHER with them?
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