silencedmajority

Hello, just finished a bunch of work on my new Cherokee. 1998 XJ, 4.0L, AX-15 manual trans, NP231 transfercase, and 8.25 rear end. I installed a Rubicon Express 3.5" SF lift with full leaf packs. Netted closer to 4.25" of lift. Also the Advanced adapters SYE and Tom woods custom rear shaft.

So while trying to use axle shims on the rear axle to set the correct pinion angle for the CV shaft (1-2 degrees of negative angle) I installed 4 degree steel shims from RE. Still got the "grinding" type vibrations on acceleration that I suppose are associated with the pinion angle being to large. So I measured, and I may have found that the angle difference is as much as 6 degrees. After the 4 degree shims! I don't see how I would need 8 degree shims (if they even make them that big) with just 4" of lift? I'm having trouble accepting that I need twice the shims most people use for this set up, or that I will be needing to re-weld the mounts on the axle.

I've attached pictures to see if anyone can help me. I measured the pinion angle according to Stu's offroading website. Also if any of you are good at editing pictures to draw in a pinion angle to measure that would be helpful. Thank you.

a1racer

are you using any after market shackles or the stock ones

silencedmajority

Stock shackles. The only lift I'm getting is from the full leaf packs in the RE SF 3.5" kit. Shackles have the open side facing towards the front of the Jeep, like I think they are supposed to be oriented.

jpdocdave

t case drop?

a1racer

have you tried a tc drop if not you might want to get the s.y.e.

silencedmajority

I just installed an SYE and CV driveshaft, and thats why I'm trying to get my pinion angle closer to zero, sorry for any confusion.

And I had a TC drop while I was waiting for my SYE, and while it did help a little, it makes shifting the trans a little weird and I don't like having my TC hanging down and not having a skid for it. I should be able to set my pinion to reduce driveline vibes without a TC drop, its just that I'm having trouble understanding why I would need an 8* shim when most people run 4* shims. Wanted to see if I'm missing a part of the equation.

jpdocdave

are the most people w/ 4 deg. shim running t case drop?

silencedmajority

When I was looking around the forums for info on what shim to order, most people with my set up were getting the 4* shim to set their pinion angle closest to zero with a CV shaft and SYE. I don't recall any of those people running TC drops.

silencedmajority

Well I was mainly trying to see if anyone had a specific experience or ideas as to why I would need such a high angle shim for such a low lift. Could it be the manual trans?

I don't want to order the set of 8* shims and find out I didn't need to or something like that.

mike37

I needed 5 deg on my 8.8

you don't need a TC drop that what the sye is for

get the right shims don't worry what other guys did

mike37

the bigger the lift you have
the pinion angle will be more

mike37

and one other thing make sure the DS yoks are in phase

silencedmajority

By phase you mean that when I remove a shaft, be sure I put it in the same way?

When I removed the front shaft I marked both ends of the shaft as well as the TC output and pinion yoke and matched them up on re-install.

But is it possible to install a new shaft (the TW I have in rear) out of phase?

Thank you for your input.

mike37

its un likely but it can happen
post a pic of the entire back DS