Hi All,

Weird issue.

2001 GMC YukonXL 1500 5.3 4L60 4X4 267,000 miles. Replacing rear-shaft universal joints.

Went out to swap out u-joints on the rear drive shaft because the differential-end one was getting sticky and all of them are factory-original nyloned-in-place units (I know right? 267,000 miles on these. Seriously I couldn't believe it either.) .

It came out easy enough. I torched the nylon out, popped the old u-joints out, filed the rust and crud off where the c-clips will live, greased up the new U'*, and put them in and clipped them in place. I added the c-clips to the caps that will be strapped to the yoke on the differential, grumbled about it taking longer than I'd prefer, and wandered back out under the car.

I got the transmission yoke lined up with the spline-key the first time. Woohoo! Then went to put the other end into the diff-yoke. Doh! It won't fit! Seems like the yoke is too narrow for the c-clips by about an eighth of an inch.

Even after wire-brushing out the little relief they put in for someday when I'd be here installing a normal (non-nyloned) u-joint.

I scratched my head some then removed the c-clips to make sure at least the caps would fit, and they do. I asked The Google about it and got little useful, except the mention of possible retainer tabs on the yoke. I checked and there were none. I looked around here and didn't see anything close.

I got out my trusty micrometer and measured. From the outsides of the c-clips I measure 68mm and from the insides of the yoke I measure 65mm . 3mm is a huge difference!

The new u joints are Napa 534G heavy-duty units.

At this point I think I'm stuck being clever in removing 1.5mm of metal off of each ear of the yoke? Seems like a bad idea unless I have a machine shop handy. Perhaps I need to buy a new yoke that is the right size?

Has anyone here run into this before? . . . and have any ideas?

Thanks in advance!

Check with the dealer to see what the GM part numbers are based on your VIN, and check the cross reference to make sure you have the right parts.

Worth a shot, will do. Thanks!

Okay I did it. Now it'* more interesting: Theirs is worse than mine.

I attached some pictures:

- "GM 0 All Three.jpg" GM'* replacement yoke and u-joint new in box on dealership counter (note c-clip grooves versus clip seats on the yoke)
- "Not Seated 0 Both.jpg" My current dilemma with the u-joint centered on yoke
- "Half Seated 0 Both.jpg" My current dilemma with the u-joint in place on the driver'* side and passenger'* side forlorn at not being close to going to its home

Forgot this one last night:

- "Compare 0 Both.jpg" The original rear u-joint at 65mm on the diff-yoke side compared with the expected replacement at 68mm.

Update: Went to my local Napa today (with the original rear u-joint and a new replacement unit in-hand) and we compared about every remotely similar u-joint they had on the shelf. No luck. They called their driveline shop that they've used forever and discussed with them. They said it sounds like the yoke got sprung inwards both sides. If I bring it to them they could spring it out. I already knew it was not bent or sprung etc. because I've been measuring the heck out of it. Either way had to get to work.

On the way to work (stopped at a red light) I looked around for a decent driveline shop. I found "You Can't Beat My Shaft!" - Welcome . It looked like just what I needed. At lunch I went over there and told my sad story. At first Bill thought I may have the wrong unit, but then figured out that I just need to squeeze it down to fit as the grease seals are designed to compress down just for this purpose. He showed me in a yoke he had there. I measured the yoke and it was 65mm like mine. I super verified that he believes the seals will be happy like this indefinitely and he said yes. He said it looks like a new design of grease seal so perhaps that'* why it'* hard to compress.

I was still skeptical.

After work I went home, ate a bite, crawled under there, and tried to compress it with the super mega robot strength in my hands. Surprisingly this did not work. I put one side of the u-joint in the yoke then used a c-clamp to compress it and then was able to push it in place like that'* how it was meant to be done. Strapped it in and drove it about ten miles at around 60MPH. Crawled under and it was cool as a cucumber on all four caps.

Success? Woohoo? I'll change the question marks to exclamation points after I drive a bunch tomorrow.

Regarding the unit that the GM parts counter showed me: those bronze-looking rings apparently push inwards with a bunch of force thereby allowing them to fit. I wouldn't have guessed that because those looked and felt solid . . . but now I look at the pictures and see that that surface of the crossbar is machined quite nicely.

I hope this experience helps someone out there. Sure was a struggle for a simple solution for me.

LOL, I didn't realize his site had that friendly title until I saw the forum convert it. Don't worry, it'* safe (unless you have drive-shaft addiction issues).