The last issue covered ways to beef up the housing of a high pinion Dana 30, commonly installed in a TJ/LJ, XJ, or ZJ. Now, this article will discuss ways to strengthen and upgrade the internal components. The internals will be upgraded with parts from Auburn Gear, including: Ected Max differential, master over-haul kit, and 4.88 gear set. The Ected Max was chosen for several reasons; Auburn Gear has a great name for strength and dependability, its electrical selectability, low/no maintenance design, and its ability to go from a limited-slip to a locked differential.This axle was a mess when it was taken apart so we began with the starting spec for shimming the pinion depth. We were hopeful that the pinion would be close to the right placement and we wouldn’t have to pull it back apart and change the depth. This axle has a baffle and slinger, which contributes to the total of the shims for the pinion depth. The shims and baffle are placed in the housing, under the inner race, and then the race is driven in. Next, the outer race is driven in. The slinger is then placed on the pinion, as well as the bearing, and the bearing is pressed on.Pinion preload shims change how tight the bearings are pushed into the bearing races. This tightness (or drag) caused by shoving the bearings into the races is called preload. The sealing surface is grooved and the bolt and strap design of the original yoke is weak. So, the yoke is being replaced with a new Spicer U-bolt style yoke. The pinion preload shimming was somewhat of a guessing game. We started with about .005” more than what it was originally shimmed, then pulled it apart and removed shims until the correct spec was achieved. The spec is checked with an inch-pound torque wrench, the beam/needle type works best. The pinion preload is checked by rotating the torque wrench on the pinion nut and reading the amount of drag, which may require a few adaptors to adapt the wrench to a socket. The spec on this axle is 12-15 inch-lbs of drag. It took about three times of putting it together and taking it apart to get it within spec.After it was within spec the yoke was removed a final time. The pinion seal was packed with grease and installed, then the yoke was reinstalled and the nut was torqued to spec.Next, we moved onto the Ected Max carrier install and started by installing the ring gear. First, the electromagnet must be removed. A small flat screwdriver was used to gently pry up between the magnet and the steel plate on the top of the carrier. It is important to pay attention to the order of the parts’ removal as they are disassembled, because they will be reinstalled after the ring gear is torqued down. The ring gear was slipped on and bolts were started. We used some longer guide bolts to help get the new ring gear bolts lined up. These guide bolts were removed and replaced with regular ring gear bolts. Be sure to use Loctite (or an equivalent product) on the ring gear bolts to ensure they stay put. A press was used to hold the carrier while the bolts were torqued to the spec of 55-60 ft-lbs.The carrier was set aside while the axle seals were replaced. The axle seals are included in the master install kit and were installed with a seal installer by Yukon Gear. The housing was also drilled and tapped at this time for the locker’s wires as well as the vent for the differential. Then the pipe barb for vent and bulkhead connector for wire were installed.Lastly, going back to the Ected Max carrier installation. We pulled the original bearings off the stock open carrier with the Yukon Bearing Puller and measured the shims under the bearings to get a starting point for the new carrier. New shims out of the install kit, the same thickness as the original ones, were placed on carrier journals and bearings were pressed on. Don’t forget to put the electro magnet on before pressing on the bearings. The carrier was installed into the housing. The ring gear side was extremely close to the bearing cap, so we clearanced the side of the cap. The cap on the other side was slightly notched to allow for better seating of the electro magnet retainer.After installing the caps to proper torque, checking backlash, and pattern, it may be necessary to pull the bearings off and move the carrier shims around. Our original carrier shim thicknesses were pretty close. Only had to move .005” from the non-ring gear side to the ring gear side. The backlash is checked with a dial indicator, rocking the ring gear forward and backwards gives a measurement of the clearance between the ring gear and pinion. Most axles spec for backlash is .006 – .010”, but always check for correct spec for your application.The Ected Max comes with two different electro magnetic retainers that fit multiple applications, so be sure to choose the retainer that fits your application best. The retainer is installed under the head of the bolt that goes through the bearing cap and locks into a notch on the electro magnet. Make sure to also tighten the bolt that goes through the center pin, Auburn Gear leaves this loose due to the carriers fitting multiple applications. Spec for tightening this bolt is in the Auburn Gear installation manual.To finish out the ring and pinion and carrier install, we put the wires through the housing and put the rest of the parts on to complete the compression fitting. To protect this investment the housing was sealed up with a Lube Locker and covered with a Riddler cover.
Lastly, the axle was filled with the supplied limited-slip additive and gear oil after being installed in the vehicle. The wiring was hooked up according to the directions in the Auburn Gear installation manual.
