What is a Leaf spring shim

[Zuul99]

So every once and a while i see these little metal plates called leaf spring shims and they are these triangular wedges that seem to go some were. they have different angles to them. what do these little suckers do?
Here is a pick, the description says "4 degree" and there by skyjacker

 

[WB9YZU]

They are installed between the spring and the spring perch to adjust pinion angle.

 

[Zuul99]

That's it? my thought was that they increase the arch in your leaf spring,by putting them between each leaf.

 

[the_weirdo]

Yep, just for adjusting the pinion angle.

 

[Zuul99]

Your chart was very helpful thanks.

 

[dick.breakey]

thats the most beautiful simple picture to help understand something new. thanks weirdo.