RE 1807 Slip Yoke Eliminator install for TJ/XJ (‘96+)

by Alex M.

When we lift our Jeeps we put the rear drive shaft at a steep angle. The higher you go the more you are prone to drive line vibrations caused by the slip yoke at the rear of the transfer case, especially on newer XJ’s (‘96+) and TJ’s equipped with the newer design of transfer case. Along with more height, drive shaft binding occurs due to the severe angles at the slip spline (shown below)

The guys at Rubicon Express  came up with a simple, inexpensive and reliable way of eliminating the slip yoke from the rear drive line with their Slip Yoke Eliminator kits (SYE's) or commonly called a " Hack and Tap". After this install you will know why it is called that! The standard kit uses a "bolt-on" machined flange that replaces the slip yoke with a fixed output yoke that will mate up with Rubicon Express's custom Spicer flanged CV slip drive shaft. This kit is designed to be installed in the vehicle without removing or splitting the transfer case. When ordering this SYE kit with the drive shaft you will be asked to give a measurement of the center to center of the u-joints (see picture below).

Now onto the install....

1) Make sure the Jeep's tranny  is in "PARK" or in gear if it is equipped with a manual tranny and block or "chock" the front wheels. Remove the stock drive shaft from the rear where the u-joint attached to the differential pinion by removing the u-joint straps, (8mm socket) then once removed, use needle nose pliers or a small flat screw driver to pry open the clamps on the rubber boot that cover the front slip yoke and t-case splines and remove slip yoke from splines.

2) Measure and mark the splined shaft with a black or red marker so that 1" of splined shaft will remain. The best way we have found to make the cutting process easier and cleaner was to use a "cut-off" wheel on a grinder with the shaft spinning. Make sure the emergency brake is engaged, the transfer case is in 2wd drive and the rear drive shaft completely removed. Start the vehicle and put the transmission in REVERSE.  While the shaft is spinning, look for the mark that you made and begin cutting. Only cut for about a minute or so at a time and let the shaft cool down for about 5 minutes between cuts. This usually take about 3 cutting "sessions". If you cut on the shaft for extended periods of time, the heat may cause your tail shaft to warp. When stopping between cuts be sure and shut the Jeep off then allow the shaft to stop spinning before putting the tranny in PARK. After you have cut the tail shaft off, grind the end square and flat, be careful not to grind the remaining splines.

3) Make sure the tranny is in PARK. Place the R.E. flange onto to the tail shaft. It may feel a little tight but it will go on. Make sure the splines match the grooves, this will give you a better view of where the center of the tail shaft is. Then use a center punch and mark the very center of the tail shaft. Next use a drill to start a pilot hole with a 1/16" drill bit, be sure and keep the drill level and square to the center of the tail shaft when drilling. Drill hole only 1-1/4" deep. I used a piece of duct tape to mark the 1-1/14" spot on my drill bit. After the pilot hole is drilled I went with a little bigger sized bit like a 3/16", then I used the 5/16" drill bit that came with the kit for the final hole. After drilling, be sure and clean out the hole with an air nozzle or a can of brake cleaner.

4) Now comes the critical time to cut threads or "tap" the hole. This requires lots of patience and time to make sure it is done right. Use the tap that is supplied in the kit and start "screwing" it in slowly and make sure it is squared and centered in the hole, the normal procedure for tapping is 2 full turns in and 1 full turn out. While cutting threads be sure and keep the tap clean of shavings. I used a ratchet with a 5/16" socket to thread the tap in and out. It also helps to use some kind of cutting oil or lubricant, I used Schaeffer's Penetro penetration oil, this is some good slippery stuff!

5)  Now re-install the flange yoke using the "grade-8"  3/8"-24 bolt, 1- flat washer and 1- lock washer. Be sure and use Loctite on the threads of this bolt. Next install the drive shaft flanged end first to the new fixed tail shaft yoke using the remaining "grade-8" 3/8" bolts and lock nuts, this is a very slow process of getting these bolts all installed and tightened. I found holding the tail end of the drive shaft with zip ties to the exhaust (if not hot) helped with the installing of the flange bolts. You can put the tranny in NEUTRAL to rotate the shaft when installing the bolts. Use the new Spicer u-joint straps that are supplied with the kit to install the rear u-joint of the drive shaft to the pinion of the differential with a 8mm socket and torque these down to ONLY 14 ft-lbs.

6) Last but not least, check the grease the CV joints and slip splines in the drive shaft, these come pre-greased from Rubicon Express. Also remember to re-tighten bolts and re-grease the drive shaft after the first 100 miles. If you have any questions or comments, please feel free to email me . 

This Rubicon Express Slip Yoke Eliminator and drive shaft was installed on a '99 Jeep Cherokee with about 5.5" of lift. The Jeep drives beautifully with no drive line vibes. The RE SYE and CV driveshaft are quality pieces and have proven to be rock-solid reliable!

To place an order, please call:

(316)776-9900