Project Overview:

Adding a lot of lift to a vehicle introduces a myriad of driveline problems. One of those problems is driveline vibration. Another problem on vehicles with a slip yoke is increased wear on the transfer case and U-joints. To compensate for both of these problems, I installed a slip yoke eliminator (SYE) kit and a constant velocity (CV) driveshaft.

Product Selection:

There are several manufacturers on the market for both the SYE and the CV driveshaft. At first, I was going to buy a SYE from Rubicon Express. But after calling around and doing a lot of research, I learned that many of the SYE kits available - including RE's kit - are "hack and tap" kits. That means you take your stock output shaft in your transfer case, cut it shorter (using a hack saw, chop saw, plasma cutter, or whatever you've got laying around your garage) and then drill and tap the end (hopefully in the center) to install some bearing plates.

Sound scarey? I know it wasn't something that I wanted to do! The folks at Rusty's Offroad recommended I take a look at Tom Woods Custom Driveshafts. I'd heard of them many times before in all the offroad magazines, and they seemed to be a manufacturer of choice. I checked out their website and I was convinced. These guys really know their stuff!

After a few phone calls and some measuring, they had me hooked up. I ordered the kit and driveshaft on Tuesday and had them on Friday. Kick ass.

It turns out that I ordered the wrong size U-joint in the pinion end of my driveshaft. So I had to send it back to Tom Wood's Driveshafts to have it refitted. It was a delay, but they made it easy on me.

Other Notes:

Installing a CV driveshaft means I will have to rotate my rear axle up in front to align the differential pinion and driveshaft as closely as possible. When I install my differential gears, I'll have to make some adjustments to ensure the pinion will get enough lubrication.

Installation:

	I started by removing the front driveshaft. It's difficult to see in the shadow of the Jeep, but it's on the ground. I didn't remove the front yoke yet, however.
	Next I removed the rear driveshaft. Here you can see how it compares to the Tom Woods custom CV driveshaft that I ordered. I actually ordered the wrong size U-joint at the pinion end of the shaft (being an idiot really sucks) so I had to send it back to them to put a smaller one on. They were really good about it. I only had to pay shipping to get it back to them. Excellent customer service!
	Then, I supported the transmission and transfer case with a jack stand and removed the stock crossmember. I had about 3 lbs. of sand from Pismo Beach dunes that poured out of the crossmember when I took it off. :)
	Since I was working alone, I opted to do the work with the transfer case attached. I don't have a transmission jack with chains, so removing a very heavy transfer case would have been awkward and dangerous. So, with the driveshafts and crossmember out of the way, I removed the splash guard, bearing seal and snap ring from the rear output shaft, and I removed the speedometer unit from the tail cone.
	Next, I removed the tail cone itself. I would be returning it to Tom Woods Driveshafts, so I was careful with it. Rather than using a chisel or screwdriver to pry around the edge of it, I used the handle of my breaker bar (which is nice and thick) to pry one of the protruding features of the tail cone against the rear casing of the transfer case. I had no problems popping it off.
	After removing the tail cone, I couldn't get the entire oil pump unit out in one piece. So, instead I loosened the six screws that hold on the back plate of the oil pump and removed the plate. I also pulled out the planetary gear inside. That left the inner plate inside the case.
	With the outer plate of the oil pump out of the way, I then removed all of the bolts that hold the rear case half in place. I pried off the rear case half. Then I removed the front output yoke and pulled out the mainshaft, front shaft and chain as one unit. I left the shift rail and spring in place.
	Next, I removed the compensating hub and differential from the stock mainshaft. I wish I'd known that the needle bearings weren't held in place by something other than the differential, because they all fell out when I took the diff off. I had to find them all and clean each one. I used a rubber band to hold them in place on the new output shaft. Even after searching for a long time, I was still a couple short.
	So, I had to buy this pack of new needle bearings. That's what I get for being a clutz, I guess.
	Once I put the new needle bearings on, I replaced the compensating hub and differential on the new driveshaft and replaced the snap rings. To do it, I lowered the diff down enough to hold the needle bearings in place. Then I pulled the rubber band down over the lower part of the shaft. You can see the rubber band laying on the jaws of the vice. In the background on the bench, you can also see the front output shaft to the right, and the stock mainshaft to the left.
	Then I put the chain back around both the front and rear output shafts and replaced them into the front half of the transfer case. Since I left the shift rail and springs in place, I didn't have to worry about putting them back in.
	With the output shafts installed in the front half of the case, I then scraped all the old gear sealant off of the mating surfaces of both halves of the transfer case. It took a while, and was messy, but I eventually got it done. Just be sure that you don't leave any dirt or grit inside either of the case halves.
	The oil pump assembly makes mating the case halves a real pain in the butt. I had to do it twice to get the pump's pickup tube and filter in straight. Use a flashlight to look in the drain hole to see if the filter is in the right position. Also, don't forget to put the magnet back into its spot inside the case. I used some MOPAR grey gear sealant to seal the two halves together. I turned the rear output shaft by hand several times to make sure it was spinning freely.
	Next I replaced the tailcone onto the rear case half. Notice the threaded hole on the shift rail housing. The tailcone I pulled off didn't have one. The kit didn't come with a plug for it, so I had to call Tom Wood's Driveshafts to find out what the hole was, and whether or not I was missing a piece or I needed to plug the hole.
	With the tailcone in place, I installed the new yoke onto the end of the output shaft and replaced the speedometer sensor.
	After the rear yoke, I replaced the front yoke and reconnected the shift linkage. (I never really needed to disconnect it. I had originally planned on dropping the whole transfer case, which is why I initially disconnected it.) I had to stop here because I still had an open hole in the tailcone (on the shift rail housing).
	It turns out that the hole in the output shaft support housing is for a sensor that came on some Jeeps. My Jeep didn't have the sensor, but others did. Since I didn't know what size it was, or the thread pattern, I had to buy a bunch of various size drain plugs to see what would fit. I tried Auto Zone and Napa, but neither of them had what I needed (and trying to explain the situation was much more trouble than it was worth.) I finally found what I needed at good old Ace Hardware. It's a 16mm drain plug.
	Next I installed the pinion end of the driveshaft into the pinion yoke.
	Then I installed the double cardan into the transfer case yoke. It's a bit tricky to get it in there, pull the U-joint up to the yoke and thread the bolts with just two hands. Take your time and you can do it. I put the transfer case in neutral so I could turn the driveshaft by hand to easily get to all the bolts to tighten them. I then applied the emergency brake then to hold it in place while torqued them down.
	With my lift kit almost complete, I was finally able to replace the front driveshaft. It's pretty puny compared to the new rear driveshaft, and I knew I'd be replacing it. I used a pipe wrench to hold the shaft while I torqued the yoke straps.