rear lowering block question

i know i know search old threads, and i did, like 17 pages of them. but here i am. question is....the angled leaf spring shims that allow you to correct your pinion angle, how do you know to get the 2" or the 4" shim etc...and then which way does the angle face?

thanks

 

Where? Speedway motors has them: http://www.speedwaymotors.com/p/3354,,_Angle-Shims.html?itemNo=leaf spring shims

How? They will install which ever way you need to adjust the pinion angle. If you do not have you need to get a angle finder, and do a search on setting pinion angle. There are some good threads on it.

 

Google "pinion angle", lotsa sources for help.

http://www.iedls.com/ptsetup.html

http://www.carcraft.com/howto/91758/index.html

http://www.wolferacecraft.com/pinionangle.aspx

http://www.stylintrucks.com/Articles/suspension-djm-pinionshims/article.aspx

Your set-up will determine how much shim you need, if any, study the links above and you'll figure it out.
Generally, the fat part of the shim is in front to increase pinion angle (I assume you have parallel leaf springs?).
I hope this helps.

 

perfect, thanks guys.

 

One more question regardin the pinion angle.....is this something that everyone corrects? You always read " blocks in the back" but adding the shims and correcting the pinion angle is this always done? What is directly affected? The driveshaft angle?

thanks

 

Assuming nothing else is changed......adding blocks does not cause the pinion angle to change.

 

No matter what you do for rear suspension, the pinion angle needs to be pretty close to the accepted "correct" angle. The factory engineers go to great lengths to get this dimension correct for driveline smoothness and long life. As soon as we start modifying and changing our suspension and ride height.....we screw up all the work they so painstakingly did.......so, we need to put everything back in order by correcting that angle by using angled blocks, different arms or links or whatever. This angle can directly effect u-joint life and prevent driveline "shake".

 

i didn't use a shim, and i have a bunch of non matching chevy parts bolted together to make a car. still works. I had to use a 2" and a 3" block to make the car sit level.