bluestar1

Have a weird situation. Need to change front wheel bearings in an 88 XJ 4x4 auto, but front caliper mounting bolts are either frozen/cross-threaded on and heads stripped out right off the bat. Got the hub bolts loose no problem though. I've worked on XJ's before but never had this happen before. I tried undoing the upper and lower balljoints, tierod, axle nut, disconnecting the brake line and tried to remove the whole spindle, but it won't come off no matter what i've tried. Is there a way to get the whole hub off w/ the caliper in place, or am i screwed? I've tried stud pullers, bolt extractors, nothing works. Also, this is a first for me, but the brake caliper piston is half exposed off the top of the brake pad (not centered on pad) and exposing the inside cup of the piston. Is this an XJ thing? or was the wrong calipers installed by prev owner? I don't recall and XJ brakes w/ the piston half exposed off the top of the pads like that before and was wondering if this is why the caliper bolts are so frozen. I'm kinda stuck and the owner needs to get this truck going asap so any advice would be much appreciated. Thank you.

SeriousOffroad

Front end on jack stands.
Start the engine.
Have an assistant turn steering wheel to the right, all the way.
Place a large socket between the socket the outer stub shaft and the inner axle. Roughly like this...

Turn the steering wheel to the left....and watch the unit bearing hub pop right out.

bluestar1

THANK YOU seriousoffroad! So, is that brake caliper piston supposed to be half off like that and not centered on the brake pad? I've never seen that before.

SeriousOffroad

pics?

SeriousOffroad

And my suggestion only applies AFTER you've got the caliper off.

Are you sure you're not trying to remove the caliper bracket mounting bolts?

The caliper on the left is typical of 90 and older D30's.

SeriousOffroad

Pads and calipers are not interchangeable.

bluestar1

Sorry, i didn't take any pics. i WAS trying to remove the 2 caliper mounting bolts in order to get the rotor off so i could pull the hub/bearing assy. I got the 3 hub bolts loose easily, but the caliper mounting bolts that bolt to the hub are frozen/stuck/xthreaded. Impossible to remove and heads stripped/rounded off so the caliper is stuck onto the hub, and thus the rotor. Was trying to remove the whole hub w/ the rotor and caliper all attached so I could drill out the caliper mounting bolts on the bench for more room. I thought i was able to and it seemed like it would all come off together. Problem was, i couldn't get it to come off the upper and lower balljoints and slide off the axle no matter what i tried. I got it to drop off the balljoints, but it wouldn't silde all the way clear because the axle would hold it on there somewhat. I hope you get the picture. I didn't take any pics of the caliper piston half showing off the end brake pad either but was hoping someone would know off hand if it's supposed to be like that. I don't have a whole bunch of experience w/ XJ's, but i've done tons of brake jobs and never seen a piston half exposed like that.

SeriousOffroad

Understood.
The piston should not be in the position you're describing.

Sounds like you're going to need to start cutting/grinding to get it apart.

bluestar1

awe man, thats what i was afraid of! I'm going to try to weld on a nut to the caliper mounting bolts to remove them, but i'm thinking the top might be a problem as far as room is concerned. I was afraid it was going to come to this. I might be able to chisel/shear off the bolt heads also. I think the prev owner installed the wrong calipers and thus why the bolts don't come out and piston cup half exposed. Thanks for all the help, much appreciated!