Level of Difficulty: Advanced
Installed By: OC Motorsports
Install Time: Approximately 3 hours
We have learned much about Jeeps and off roading from our Rubicon and our friends at OC Motorsports. One of the most important lessons has revolved around axles and gears; it turns out they are one of the most important upgrades you can install on your Jeep. Our 2015 Rubicon came equipped with workhorse Dana 44 axles, lockers and 4.10 gears. As we added a lift and 37” tires for increased off road capability it was apparent that we needed to bring our driveline up to a new level of performance. JC Whitney Centennial Sponsor Yukon Gear & Axle stepped up to guide us through the options available for our Rubicon and based on our plans they suggested their 4.88 ring and pinions and upgraded front axle shafts. Yukon Gear offers these components “ala carte” or kitted with everything ready to install. With all of the parts ready we asked the crew at OC Motorsports to work their magic on our Jeep. Jason was assigned to our project and with his experience with axle upgrades we were in great hands. Jason estimates that he has done more than 200 axles in his tenure at OC Motorsports. With the Jeep on the lift and the wheels and brakes removed Jason started with the rear axle and removed the differential cover and drained the oil, then pulled the axles to get to the ring and pinion.
Jason removed the bolts, caps and locker actuator before he pulled the differential from the rear axle. It’s important to keep the caps organized since they need to go back in their original positions. The he unbolted the 4.10 gear and replaced it with the Yukon 4.88 ring. Jason pointed out that Threadlocker is critical here. This will have a major effect on the driveability of our Jeep restoring the acceleration we lost with 37” tires.
With the differential out of the axle Jason removed the stock 4.10 Rubicon ring and installed the Yukon Gear 4.88 ring.
The new ring is a perfect fit and Jason bolts the 4.88 ring to the differential and moves to the next step; removing the stock pinion. Here’s where Jason’s experience is going to be very helpful as installing a new ring and pinion is an exact science. Lining up the components involves precise measurements to ensure the ring and pinion interface correctly for maximum longevity. Fortunately Yukon Gear instructions are very elaborate, covering all of the critical steps. Jason removes the stock pinion and driveshaft and presses the supplied bearing onto the new pinion. Next up is to test fit the ring and pinion to ensure the correct depth, preloads and backlash per the instructions. Here’s the pinion in position ready for the differential, and Jason has measured and shimmed the differential with the supplied parts in the Yukon Gear kit.
With the rear differential in position Jason reassembled the axles and cleaned and resealed the rear cover with a fresh bead of RTV and refilled the differential with oil.
Now it’s time to tackle the front axle where Jason will replace the ring and pinion with Yukon Gear components. Since the Rubicon runs Dana 44 axles front and rear the process is the same. The front axle is also getting upgraded with Yukon Gear axle shafts and stubs. Jason drains the front differential and removed the front brake calipers, rotors, drive shaft and track rod to access the hubs and unbolts them from the axle.
With the stock axles out and the required seals swapped over Jason pressed the supplied Spicer u-joints on the upgraded axles. You can see the difference between the stock axles and the Yukon Gear axles here-notice the reinforcing web and thicker ears on the u-joint yokes and the diameter of the Yukon Gear axle shaft.
With the axles shafts ready, Jason swapped the Yukon Gear 4.88 ring and matching pinion into the front differential using the same steps as the rear axle.
With the new axle shafts in position Jason bolted the hubs back into position and reattached all of the components he removed including the driveshaft, brakes and track rod ends. Lastly, the front differential cover was refit and filled with oil. There was one last step required before we could drive off-the Jeep’s computer has to be recalibrated to deal with the new ring gear to eliminate any issues with the stability system and send an accurate reading to the speedometer. The Yukon Gear 4.88 ring and pinion makes a noticeable difference in acceleration and the enhanced gearing is a welcome upgrade for any Jeep on larger tires and tired of sluggish on road performance. With the Yukon Gear axles installed, a known weak point in the driveline has been addressed and we can’t wait to take them out on the next trail ride.
Brands featured in this episode: