So I am going to need to overhaul at least one of my rear calipers on my 89 XJS convertible, and the rotors and pads are looking a little tired too, so the question is: Should I just pull the whole IRS and do the rest of it while I am at it? It could probably use bearings, springs, and shocks as well. I did the bushings last year, so those should be ok. I did a bunch on the front end a couple years ago. I did most of the work before I ended up having to pull the front subframe off anyway. I felt really dumb with how hard I worked getting at stuff when I could have just pulled the whole mess and had much easier access. It doesn’t seem so bad to pull off the IRS. If I do pull it, anything else I should think about taking care of? Thoughts?
I pulled both rear calipers and changed the rear discs on my '85 without pulling the rear end. It’s going to be a PITA either way. In some ways leaving it in the car was easier because I could drop the lower control arms to get the discs off without flipping the cage over. If you plan to pull the discs as well as the calipers, you can remove the disc and the caliper/parking brake caliper combinstion as a unit. I’d had just done that in the photo below. It just barely works, but saves a lot of time. The big advantage is that you can bolt the parking caliper onto the main caliper off the car and don’t have to do it blind.
Technically, that’s possible…
What about the clearance on caliper and studs? Is it possible to get confirmation on this method from anyone performing disc change with wishbone lowered?
Yes it’s technically possible to do the callipers in situ, you might save some time, but you have to work on your back all the time.
But if you think your bearings need attention you just answer your own question… Imagine doing all this work and then having to pull the IRS anyway to change the bearings.
What do you mean exactly Janusz ?
As far as the discs are concerned, when I did mine the new ones dimensions where exactly the same as the old ones so I didn’t have to fiddle with the calliper position.
I vote for pulling it out. I did it and was amazed how easy it was. Gave me a good opportunity to check other compenents; found a tear in the cage and some other stuff that needed repair.
If you are asking yourself this question the answer is always yes.
Do it once thoroughly and never do it again.
Pull it out. You can then replace the cage mounts (use OEM not Uro) and make everything right. Also easier to replace the fuel lines that run over the top. The time and frustration of doing the work in situ is not worth it imho.
When you get to overhauling the parking brakes you will see the wisdom in removing the cage.
Definitely worth pulling. I will eventually do the same.
Similar situation, i decided to pull front subframe. I discovered so many little things that needed addressing that i could not see otherwise, and so many extra tasks that were dead simple to take care of.
Just give yourself time to deal with the extras. Definitely do over axle fuel hoses. I did mine with IRS in place, doable but not fun.
Thanks everyone. I was thinking pulling made sense, and I appreciate everyone’s confirmation. Wish me luck! SNG and Moss are gonna make some money from me! 
Aristo,
Got rear rotors replacement job upcoming, hence my question.
I’ve heard mixed feedback in terms of doability with wishbone down and driveshaft taken off.
Do I still need to remove calipers to take out the rotors?
I am quite certain you have to.
As I said though, the replacement rotors fitted without any issues.
Yes. As with any disc brake setup, the caliper is on both sides of the rotor.