power steering pulley

[alotadust]

making something different,
using an aluminum PS pulley, with .625 dia hole,
and PS pump shaft is .750
what interference should i allow for press fit?
alum will expand more than steel,
thinking of using threads in the pump shaft, for extra precaution,
using a bolt , just in case,
anyone?

[Baprace]

I would machine the pulley to use a set screw , with a little flat on the pump shaft. JMO

[alotadust]

so no one knows how much interference the pulley should have?
with all the experts on here, I thought someone might have some experience with this,

set screw is a good idea, thanks!

[Baprace]

alotofdust , not sure of the press needed because you are trying to use aluminum on steel , steel on steel would be approx .0004 - .0006 , that is my opinion on the press needed.

[alotadust]

Baprace, thx,
at least I have a starting point,
its been my experience alum will expand (depending on temp)
3-5 thou.
so I may aim for .010-.012 interference