Chev drop Shackle and Pinion Angle

I've been doing some searches on lift/drop shackles for the XJ... General consensus is that 1" lift shackles seem to be the most popular. I have read about using a Chevy drop 2" shackle for the rear end for approximately 2" of lift.

Through my searches I have not really found out anything good or bad about them (with the exception of one picture showing a shackle that completely collapsed)

With a 2" shackle is it going to throw my pinion angle out the window? My leaf springs are fubar... Would I be much better off running a shackle that will only give me 1" of lift and possibly aid in correcting my pinion angle?

I will be bastard packing the leafs (have 1/2T chev leafs in the garage waiting for install). I figured I would try and gain the most lift out of the shackle so that it will allow the pack to flex and ride great (and hopefully get away with only using 1-2 leafs out of the chevy pack)

Edit: I forgot to mention that I am going for a ~3" lift

J-Roc said:

...With a 2" shackle is it going to throw my pinion angle out the window?

Click to expand...

A 2" longer shackle will certainly change it. A 2" LIFT shackle will have to be 4" longer, and will change it a LOT.

Figure the leaf spring is 36". That's ballpark, I dunno. Basic trig, 4/36=0.111, arcsin(.111) is more than 6* you'll be rotating the pinion upward.

That's a LOT. Unless of course you're going sye at the same time, and NEED to bring it up...


Robert

You forgot to mention if you have an SYE or not. I've got a 4.5" lift plus Chevy shackles and I don't use any shims. I do have an SYE, so the shackle helps point the pinion in the right direction. The best thing to do is install the lift. Then measure your angles and then correct accordingly. Each vehicle is unique and there are so many variables involved it's difficult to determine exactly what will work best for your vehicle ahead of time. With an SYE, pinion angle should equal your driveshaft angle or maybe be a degree or two below (again the exact angle just depends on your vehicle) Without an SYE, Pinion angle should equal your T-case output shaft angle (or maybe a degree or two higher) It's something that you'll have to play with a little to find the sweet spot (no vibes). Use angled shims and shackles to make your adjustments.

i ran a drop shackel on my xj, gave me 2.5 inches of lift, i had upcountry springs tho...

wore my leafs out, but i had no vibes