Guessing this was on disassembly? There's a very cool brute force BFH method I've used since I saw it (on here) that gets every joint I've ever dealt with out in seconds/minutes. I've used it after people couldn't use the socket/vise method and the caps popped right out. My thought is that the difference between an impact load to break it loose from the shaft and attempting to press out an old cap is huge.
Big_Mark originally posted it and the photos in his thread are now gone, so I just recreated it linking a video. I've referred to it enough over the years that it's worth redoing for a new "generation". Thanks for the "nudge" to do this:
That's a great video and the same technique we used on the farm. I've never had it fail me, until this front axle shaft. The caps were pretty rusted in. I started with a normal sized ball peen hammer, then a 3 lb mini sledge. When that didn't work I put the joint in the vice, put and put it under load. Still nothing so I decided the best plan of action was to whack the vice with the mini sledge to give a shock load. This promptly broke the back half of my vice off.
Then I went and used a friends press (what I should have done from the start). It took quite a bit of effort to push the old out. Enough that the ears of the yokes were bowed slightly in. The C clips wouldn't be able to lock the new joint in place as they were. I improvised and used 2 3/8" bolts with washers and nuts pointed tip to tip with a bushing to keep them aligned. When you tightened them together it would spread the ears back apart. After that, the new joints went back in and the clips went tightly in place.
Just wayyyyy more work and effort than I have ever spent changing U-joints - including the glued in GMs.
In 2wd with hubs unlocked you obviously don't notice it since nothing is turning.
In 2wd with hubs locked you may hear some clicking in turns. I couldn't hear it, so I jacked one tire up at a time and spun it both directions. Light clicking.
In 4wd with hubs locked you will notice a difference. Especially on pavement, or anytime with good traction. If you coast through a turn it will ratchet. However, most turns under power will cause scrubbing and binding since the locker will be engaged.