Upper control Arm bushings in the D30 axle
 

While my 1985 D30 axle is out (2001 XJ)
I am replacing the upper control arm mount bushings (the ones on the D30 axle)
Searching for them all I find is "Upper control arm bushings",, I assume these are the ones IN the control arm

What are the ones "In the axle" called?

Slack

Same thing. Sometimes they are sold in pairs, sometimes in sets of four.
The same bushings are used front and back.

Good idea to change them while the axle is out. They are a bear to do
when it is still in the Jeep.

Thanks,
ordered a pair of Moog from Amazon ($12)

Slack

At NAPA they’re listed as upper and lower front and rear. Front being axle end and rear being chassis end. If I remember correctly the lowers use only one part number and the uppers a different number. So the 4 uppers are the same and the 4 lowers the same.

I replaced my upper control arms on my WJ and they came with the chassis end bushings in them, but you had to buy the axle end ones separately. IDK about XJ's, but on mine they were different. They were a bastard to get out! Especially the one on the diff. Nobody in all of Syracuse had them in stock and I got them from Quadratec shipped overnight. I knew better than to take it apart until I had them in my fat little hand.

I bought all 4 arms new with bushing. They weren't much more than just the bushings and it saved a lot of work. The pisser is on the WJ, the front lower bushings are length compensating ones that allow the axle to move a little, but they wear out quickly. Smoother ride, I guess. Mine were so bad that the axle was torquing up when you hit the brakes.

I have done this job on two XJs. If you are just replacing bushings (which is what I did), an air chisel and a ball joint press will be your friend. I use a big drill bit to drill into the bushing to make some room for it to compress. Then I hit the edge of the metal carrier with a pointed air chisel to start compressing it in. then finish with a flat air chisel to push it out. On one, I used poly bushings. Much easier to get the new ones in. On the other, I used standard bushings. Make sure you put something in between the ears on the control arms or they will bend in when you hit or press the bushing in. On the axle ones, I used an air chisel to get them out (be careful if you are using poly as you will need to reuse the metal sleeve for the passengers side). I then used a ball joint press to get the new ones in.

An air chisel is the best way to change them, you would have to get creative to do it any other way.