ok so i have an 89 xj lifted 6 1/2 " with the sye and a tom woods drivline. i have havn't changed any gears ring or pinion. i have 30" tsl mudd trac tires. i shouldn't be breaking u joints. not the cardon joint but the u joint. i havn't put it under alot of stress and i can't figure it out. please help.

 

Which of the eight is breaking? And what are you ususally doing when it breaks?

 

how are your driveline angles? Maybe they are set up incorrectly. Can't think of another reason this would happen except under extreme circumstances (not you)

The pinion should be 2 degrees below being pointed straight into the drive shaft. It should not be parallel with the TC output/ground

http://www.4x4wire.com/tech/pinionangle/

 

that's what is really strange all the angles are fine ihave 1/4" wedge shim on the rear leaf springs and a 1" transfercase drop it maybe just cheap u joints. the one that twist is the rear at the axle pinion.

 

You are saying that you have a SYE, cardon shaft, and a one inch transfer case drop and you are still busting u-joints?
I'm not a set up wizard, but that just doesn't seem right if the pinion angle is anywhere near correct.

 

Could be binding up at full droop.

 

OP - what are you generally doing when it breaks. Just driving on the street or articulating the thing pretty good?

 

which u-joint are you having problems with? is it a front axle shaft u-joint, front drive shaft u-joint or one in your tom woods rear drive shaft?

you shouldn't need a transfer case drop or rear leaf shim if you have a slip yoke eliminator.

how much lift do you have? something just isn't calculating properly.

 

x2

 

well the first one i thought it twisted after a wheeling trip. then this new one havn't even wheeled it yet and it has done the same thing.
i'm begining to think maybe just cheap u joints. going to buy a heavy duty one today.

 

axle wrap?

 

no i have the full rough country 6.5 lift on it and i bought everything they recomended for it and followed every single instructions. everything is torqued to the right settings and has been gone over several times to insure that everything was how it should be.

 

My bet is crappy u-joints.. where did you get them? advanced auto? Their crap is always of way lower quality.

Other than that... stop dumping the clutch at 5k

 

Yea the standard ujoints at AA are crap. The performance ones they carry are actually pretty good (with the red urethane seals)

 

go to napa and get the heavy duty ones with a grease sert. i went through u joints like crazy, all 8. bought the expensive ones from napa and havent had a problem with them since. but keep them greased!