Universal Joint Replacement
If you've never removed a universal joint that's held in the yoke by way of the locked-in-place-with-nylon method of retention, then I can categorically state that you've missed out on precisely nothing
, aside from one of the few tasks in all of existence that can take something as fun as "fire" and reduce it to an "Are we f****** DONE with this, yet?" experience, all while - likely - destroying a few of your far-too-valuable brain cells and causing you to yet again
question the wisdom of an automotive manufacturer that's already given you more than a few "What the hell were they thinking?" moments. To get this particular joint knocked out and replaced you're going to need a combination of heat and pressure; most people suggest a ball-joint press and a propane torch, but since I didn't have either of those on-hand I improvised the former from a large clamp and a socket, and I substituted an acetylene torch for the latter.
Pictured: Less fun than it should be.
The technique is pretty simple: apply pressure to the joint caps with the press, apply heat to the yoke with the torch, and wait for the poured-in-place inner nylon retaining ring to soften, expand, and burn its way free of the yoke. I did my best to keep an even heat on each side of the yoke by moving the torch from one side to the other in ten-second intervals, and within a minute or two the plastic had begun to expand and drip out of the channels that were used to inject it...which of course put the molten plastic squarely
in the path of a 6,300° flame and likely created nineteen different kinds of brain-eroding fumes by way of the resulting combustion.
Pictured: Me loves to burning the plasticses.
If you look closely, you can see a rope of grayish nylon that volcano-ejected itself out of the port on the side of the yoke before catching on fire...and in all seriousness you probably don't want to be breathing the smoke that will come off of this stuff when it burns; you may go full-retard without any intention of doing so. I had a fan pointed in my general direction and it dispersed the nastiness pretty quickly, but there was still a noticeable aroma of burnt plastic in the air...so this might best be done outside, instead of in the back corner of the garage. After the plastic ceased dripping from the ports in the yoke I began a process of repeatedly tightening the C-clamp and then applying a bit more heat to the yoke; after several minutes and repetitions, the joint finally came free.
Pictured: Gotcha, b****!
To be honest, I was starting to get pretty concerned about destroying my driveshaft yoke; I went through the "tighten and re-heat" sequence a dozen times or so and only managed to move the u-joint about 1/32" for each iteration, and I was almost certain that I was applying too much heat and/or pressure to the yoke. The joint was firmly
stuck in place, and from everything that I've read on the procedure it seems that I had a lot more trouble than most people have had...but after the stock joint finally
came free the yoke itself seemed no worse for wear. I can't say the same for the joint itself, though; the needle bearings on one side were basically seized into the joint body, so they probably weren't doing their job all that well.
After the joint is removed, there may very well be a bit of nylon residue still present in the yoke's inner channel; it's not imperative to remove it, but since it seemed somewhat loose and charred and generally unfriendly to the process of installing a new joint I decided to take a stab at getting it all out. The best tool I found for the job was a dental pick; they're basically purpose-built for this kind of thing. A word of caution, though: dental picks are made of a very
hard steel and they will easily scratch and gouge the metal of the driveshaft yoke...therefore, I suggest being careful and delicate in their application, because hurrying will likely do nothing except imprint a bunch of scratches on the inside of the yoke's bearing surface. A couple of minutes of careful effort will get rid of the majority of the remaining plastic and also allow you to temporarily understand what it's like to be a dentist.
Pictured: Except that you can't gleefully bill the yoke for several hundred dollars when you're done.
Once all of the plastic is cleaned out the new joint can be installed...and from this point on out you're dealing with a conventional u-joint replacement. There's nothing spectacular about it and there are about nine thousand different tutorials that have already been written on the process; the tutorial on Stu's website
is one of the better and more comprehensive, and it's the version to which I referred. After another few minutes of effort with the clamp and a deadblow hammer - I got to use a hammer because the clamp decided to break
midway through the installation of the new joint - I had the new 793x in place, along with its retaining clips.
Pictured: Sexy, shiny Spicer-ness.
At that point I was tired and my back was hurting and a job that should have taken fifteen or twenty minutes had taken over an hour, so I hung it up for the night due to sheer frustration. I probably should have kept going, though, because on resuming my efforts this morning I promptly forgot all about getting some grease in the CV centering ball until after I'd already re-installed the driveshaft, tightened down the bolts on the transfer case yoke, and taken a picture of it.
Pictured: "Damn it..."
I know I'll have to pull the shaft again in the near future - likely when I pull a lot of other stuff out for the Suspension-Cycling and Axle-Locating Extravaganza - so I decided to let well-enough alone and move on to the pinion yoke; I noticed that it had a bunch of dirt and scale rust on it, so I took a brass brush to it and cleaned the entire thing up.
Pictured: Which apparently made precisely zero cosmetic difference.
Truth be told, I wasn't trying to make the pinion yoke any prettier; I simply wanted a relatively-clean surface for the new joint to bear upon, and the removal of the loose rust and accumulated dirt from the yoke and its retaining caps was too quick and easy of a job to skip. After this abbreviated cleanup step was completed the new Spicer joint was centered on the pinion yoke and tapped into place; be careful when doing this, because if the joint is off-center one side or the other will bind up on one of the pinion yoke's cap-retaining "ears" and damage to the new caps can occur. If you have the joint in the right spot it should pop right in and happily stay put.
Pictured: And if it DOESN'T want to stay put, feel free to use threats, coercion and witchcraft.
I noticed a strange thing when re-installing the pinion yoke caps: they looked symmetrical but seemed to have a "correct" orientation, and would only allow the cap screws to thread into the yoke when installed exactly as they were from the factory. I didn't think that this even could
be an issue, so I wasn't paying much attention when I put them back on; I assumed that they would fit on either side equally as well as the other. After failing to thread the cap screws into place and - at length - going back and examining my reference marks, I realized that I had the caps flipped side-to-side and inside-out from their original orientation. When I placed them back in their factory-installed configuration they lined up and snugged down without any effort at all. Party!
Pictured: And I got to use my favorite ratchet! Bonus!
After all of the cap retaining screws were installed I went back and torqued them into place as best I could; I should have used a small torque wrench for situations like this, but I couldn't do so because I don't have one. Instead, I was going on dead-reckoning in regards to the torque value and I don't particularly like doing that kind of thing...so, hopefully, everything will hold together now that it's all put back together and working.
Pictured: Functional front axle! Great success!
I didn't get around to the locker compressors or the switch mod, but those are fast approaching. Stay tuned; maybe I won't break anything next time.