FleXJ01

I Have shackles and bastard pack for almost a 4" lift In rear of '01 with minimal vibration, but defiantly noticeable. I was wondering if I could just throw some shims on the axle? Thanks

Jeepjunky

shims are more of like a temporary fix, while a SYE is like a long term fix. you can use shims but it would be best to get a SYE

FleXJ01

When you say "temporary fix", does that mean like it will stop vibration but still may wear U -Joints? thanks

Gorillaxj

not necessarily, only real pinion angle adjustment is at the axle mounts, can either shim it (perfectly fine) or cut off the axle brackets and weld on new ones with the correct angle. both just as affective. the shims go on with the centering pin and are bolted to the leaf pack. so it wont spit or or cause problems.

SYE will fix the binding u-joint at the t/case, by replacing the 1 u-joint style with a double cardan joint the can work with the harsh angle caused by the lift without binding, but wont change the pinion angle.

Shouldn't wear anything if you set it up at the right angle. depending on SYE or no SYE the angles will be different for no vibes/wearing parts.

Jeepjunky

srry that was suppose to be more of like a reference, i should have worded it differently

the buddmang

You sir, are very misinformed.

Axle shims are used to fine tune pinion angle after installation of a sye OR a tcase drop. They dont offer enough of a change to provide the correct pinion angle without a tcase drop or sye.


They a PERFECTLY FINE to run, in fact...most guys with sye's NEED to use them to adjust the pinion angle to correctly setup a cv driveshaft. I have 4" of lift on an 01 limited, i run a 1" tcase drop and 2.5* shims and have almost ZERO vibes.

buckshot500

With the stock shaft, the pinion angle is supposed to match the angle of the t-case's output shaft.

Lowering the t-case, also helps put a little more of the slipyolk back over the output shaft.

In other words engaging more of the slipyolk's spline length.

With a double Cardan shaft, the pinion angle should match the driveshaft angle.

the buddmang

Should be 1* below matching the driveshaft angle. Not perfectly straight.

the buddmang

ON a c.v. setup, the pinion angle should be 1* below centerline to allow for change in pinion angle under acceleration.

the buddmang

So, in conclusion, you can use any combination of motor mount lift, tcase drop, sye, hackntap, shims, or re-welded leafspring perches to aquire the correct pinion angle to relieve the stress and vibration on your u-joints.

There are "ok" setups, and there are "excellent" setups. They all accomplish the same thing. Research your options, and buy what you can afford for the wheeling you are trying to do.

helmut

My Jeep is sitting at exactly4.25" lift. (I measured from the axle tube to frame). I am running 4.5in RC leafs with third leaf removed and RC relocation brackets. I have 4degree shims and zero vibes. My Jeep is a 2000 with a c8.25 axle. When I baught it it had a tcase drop. I have since removed it and was going to put an SYE . After removing it I still have absolutely no vibes. I wheel the truck a fair amount and had no problems so far so it works. As far as ujoint wear etc. I don't know but so far so good. I will still get an SYe soon as I am going up one more inch with shackles but at 4.25 its perfectly fine, at least in my case.

FleXJ01

Something like this : http://www.ebay.com/itm/BDS-Axle-Shi...9#ht_500wt_689


I guess can't hurt to try this first as its cheap... Thanks

helmut

Exactly. This put my pinion angle almost in a straight line with the driveshaft. Also, after I installed the lift I tried it first without shims and it did wobble a bit, even with the tcase drop that I use to have.