I am running Hotchkis 2" drop rear leafs with 2" drop shackles and was wondering if I needed to install pinion shims? I have no vibration at any speeds but I was just wondering if I was putting my driveshaft in a bind on the launch. Is there anyway to know for sure?

 

I have just the 2" hotchkis leaf springs and I haven't installed any shims yet. I will one day, I just never remember to research exactly how to figure out the angle I need. Anyway so far it's fine without it. Don't know how you would be with the 4" drop though.

 

For every 1" of drop you need a 1 degree shim. That's a generic rule of thumb. If you just had a set of shackles on I wouldn't bother because the driveshaft is at a zero degree angle. Zero to negative 2 degrees is preffered. So, Mr. Hankfan, If I were in your shoes I'd get a set of 2 degree shims.

 

Thanks for the info Rob.

Now which way should I install the pinion shims, with the fat end toward the motor or towards the rear of the truck?

 

Anyone?

 

You need to put the fat end toward the rear to make the pinion yoke move up. Good Luck!!!

 

Well, since when you lower your L your pinion angle goes up or positive. So to make it between 0 and 2 deg. negative you need to put the shims with the fat part of the shim towards the front of the truck. I had to use a 5 deg shim for mine.

 

What he said. Fat part facing the front

 

Wait, I'm confused

I was under the impression by lowering the truck you were making the pinion angle more and more negative?

I thought to move the pinion angle back to zero the fat end of the shim must face the rear of the truck ?

I could be wrong and I am just trying to understand. But the axle mounts below the leafs correct. Well if you place a shim between the axle and the leaf with the fat end forward won't that force the pinion angle to become more negative?

 

anyone???