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Joe K · 11-01-2019, 07:57 AM

Some -run out of the hole is normal. If you put the retaining pin in place and tighten the nut, it should drive the kingpin to the outside and "pin it" against movement.

How much is tolerable IS a question however. Front to back movement of the pin in its hole during service is unacceptable.

A local machinist DOES on occasion put bushings in the hole. His rationale is along the lines "I've never had one fail, never seen one failed, never heard of one failing after bushing." And I expect he may rely a lot on "if it doesn't fail in installation then that is proof of a long service life" (Think the side compression of the retaining pin/wedge.)

The engineer in me would do it - but be sure to put minimal material to the bush, perhaps no more than is necessary to "clean up" the hole - after all, that material has already been "displaced" and it hasn't failed yet.

The one axle I saw the machinist doing this to he had mounted in his bridgeport and was in the process of fly cutting the bushed hole - which brought the subject to my query.

Joe K

11-01-2019, 07:57 AM	#11
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Perch Pin Play... Some -run out of the hole is normal. If you put the retaining pin in place and tighten the nut, it should drive the kingpin to the outside and "pin it" against movement. How much is tolerable IS a question however. Front to back movement of the pin in its hole during service is unacceptable. A local machinist DOES on occasion put bushings in the hole. His rationale is along the lines "I've never had one fail, never seen one failed, never heard of one failing after bushing." And I expect he may rely a lot on "if it doesn't fail in installation then that is proof of a long service life" (Think the side compression of the retaining pin/wedge.) The engineer in me would do it - but be sure to put minimal material to the bush, perhaps no more than is necessary to "clean up" the hole - after all, that material has already been "displaced" and it hasn't failed yet. The one axle I saw the machinist doing this to he had mounted in his bridgeport and was in the process of fly cutting the bushed hole - which brought the subject to my query. Joe K __________________ Shudda kept the horse.