my t case is messed up. can this cause there to be issues when just in 2wd? when in 4 it makes a god awful grinding noise; what i assume to be the chain rubbing on the other internal parts. when in 2, it is a light clunking and popping thru the wheel and breaks that you feel, not so much the loud grinding of 4. any help is REALLY appreciated.

 

Have you checked the front axle ujoints, front drive shaft joints,as it turns even in 2wd

 

the front shaft has allot of play in it, aprox. 1/4" or so. has for some time, as far as i know. the t case noise has progressively gotten louder when in 4.

 

I've just fixed my XJ for something similar. A grinding noise that was barely audible in 2wd and horrific in 4wd at speeds over 30mph, it sounded like a really messed up TC. The cause was the front driveshaft even though there were no play in it!!

I haven't disassembled it yet to check but I believe it's the centering yoke in the cv joint thats making the sound.

Have you driven your car without the front driveshaft?