I'm installing some new axle joints on my D30 and had trouble getting the correct axle joints (u-joints?). The first set was to small on the caps and I had to return them (after wasting a day waiting for a ride) to try and get the correct size. I took the old joint to Napa and they matched it up and found that what mine needed (according to their book) the u-joint for anti-lock brakes. Since I have no anti-lock brakes I thought this was odd. Did Jeep use anti-lock axles when the standards ran out on the line? Also, their book was incorrect for the front drive shaft. Mine has a constant velocity type universal joint at the transfer case (3 u-joints total) instead of just two standard u-joints like their book calls out for. I looked online and didn't see any other mention of this type of drive shaft on a TJ. Did I get a freak drive shaft??? Anyway, the different sized axle joints might be something to watch out for when your stocking up spare parts for the trails.
Tqm
97 TJ (Mystery Dana 30)