Pinion angle shims

[Jackrabbit41]

So I need to put in 2 degree shims. This light seem stupid but does it matter what way they go in? I've thought about it a lot and can't figure it out.

[HOrnbrod]

Of course it matters. An axle shim is a steel (don't get the aluminum ones) wedge that goes between the axle spring plate and the spring. For SUA if you want the pinion snout to go down (decrease the pinion angle) you install the thick end toward the rear. To raise the snout reverse the shims with the thick end to the front. After my lift, I had to use 3* shims with the thick end facing the rear to lower the pinion snout back down to about a degree below parallel, because the pinion rotates up under acceleration. The goal is to have the tranny/tcase and the axle pinion shaft on the same parallel plane when driving. If you are SOA the shims are installed in the opposite direction as for SUA. You can determine how many degrees you need to rotate the pinion snout up or down by using an angle finder. What's your current pinion angle?

 

 

EDIT: And no, it's not stupid figuring out what degree shims you need and which direction you need to rotate the axle to get pinion angle right. It is confusing. :thumbsup:

[Jackrabbit41]

Of course it matters. An axle shim is a steel (don't get the aluminum ones) wedge that goes between the axle spring plate and the spring. For SUA if you want the pinion snout to go down (decrease the pinion angle) you install the thick end toward the rear. To raise the snout reverse the shims with the thick end to the front. After my lift, I had to use 3* shims with the thick end facing the rear to lower the pinion snout back down to about a degree below parallel, because the pinion rotates up under acceleration. The goal is to have the tranny/tcase and the axle pinion shaft on the same parallel plane when driving. If you are SOA the shims are installed in the opposite direction as for SUA. You can determine how many degrees you need to rotate the pinion snout up or down by using an angle finder. What's your current pinion angle?

 

 

EDIT: And no, it's not stupid figuring out what degree shims you need and which direction you need to rotate the axle to get pinion angle right. It is confusing. :thumbsup:

It's at 6 degrees right now and I need around 8. I already have 2.5 degree shims because assumed Id need them

[Jackrabbit41]

It's funny because I stopped by a good mechanic here in town and it took him and I awhile to figure it out. Haha