How To: Replace A Jeep Rubicon OE Dana 44 Diff CarrierPosted in How To: Transmission Drivetrain on May 27, 2016 0) (
You never know when a carrier will fail or if it ever will fail. After 10 winters in New Hampshire, our ’05 Rubicon Unlimited exhibited a major case of rust rash, but we never expected it to attack the Jeep’s insides too.
On an easy club Christmas party trail, our Jeep’s rearend suddenly started to feel like an axle had broken—it would thump, catch, and snap. Strange thing is it only did all these things during a turn and not while it was driving straight ahead. Even the slightest change in the steering—either right or left—would cause the rear differential to sound off and cause the Jeep to shudder. Last time that had happened, a Wentworth key broke on our Scrambler’s two-piece axle.
Since the ’05 Rubicon’s Dana 44 differential had already been equipped with Alloy USA high-tensile strength 4340 chromoly heat-treated, tempered, and induction-hardened axles, we couldn’t understand how one could break, especially on such an easy trail.
According to Precision Auto in Kingman, Arizona, the cause was not its final trail but its 10 winters of snow- and ice-covered highways. The diagnosis was that a decade of slipping and sliding on the asphalt—traction shifting back and forth between the two rear tires—had caused excess stress to the side (aka spider) gears. When we added the weight and additional traction of Yokohama Geolandar M/T 35-inch tires and steel beadlock wheels, the side gears had finally crystallized and shattered on that easy sandy trail. A really crummy Christmas present!
As it turned out, the bits and pieces of the spider gears caused so much damage the entire carrier assembly had to be replaced. Omix-ADA offers a few different kits for the Jeep’s Dana 44 differential, depending upon its gear ratio and whether it’s equipped with a Tru-Lok (OEM locker) or a Trac-Lok (OEM limited slip). Since Rubicons are equipped with the Tru-Lok air locker from the factory, we chose the Omix-ADA Tru-Lok differential case, 05-06 TJ Rubicon RHD (SKU 16505.27).
Changing out a carrier involves almost the same tasks as changing gear ratios or replacing a ring-and-pinion set (except you don’t have to break in the new carrier), so if you don’t have the tolls and the know-how, you’ll need the help of a shop with experts in differentials with all the proper hardware. We followed along as Craig Holder and Paul Schupp of Precision Auto did the expert labor tasks involved with changing out the carrier.
Special care must be taken when installing the axle lock sensor (photo xxx). Its conical little “hat” must be placed exactly against the locker plate because when actuated, the locker plate pulls the “hat” which in turn actuates the locker engaged dash light. If the axle lock sensor is not aligned properly with the locker plate, it could break, possibly resulting in a computer malfunction.
Regardless of whether it’s a rocky horror trail or an easy sand wash, a differential can self-destruct at almost any time, especially if it’s seen a decade of harsh New England winters and almost 100,000 miles.
This is the actuator plate for the Jeep’s OEM air locker, under which the sensor cap must be located during final assembly.
This ring goes on the actuator plate. During final assembly the air hose slips over this fitting. The ring is secured in place by the carrier-mounting bolts that go through the two eyelets shown here.
Omix-ADA offers a complete differential rebuild kit, which includes all the bearings, bolts, gasket material, and hardware shown here.
We used blue Loctite on all the bolts holding the ring gear to the carrier. It will stop them from backing out during high-rpm use.
The ring gear bolts were torqued down according to the specs from the manufacturer.
A carrier bearing was pressed into each side of the carrier.
Before reinstalling the completed carrier assembly, we thoroughly cleaned the pumpkin’s insides with a brake cleaner spray. A magnet was also used to make sure all debris from the blown side gears was cleaned out. We used the brake cleaner spray to clean the axle housings too.
We carefully inserted the new carrier assembly so that the ring-and-pinion gears meshed properly and the carrier’s bolts were correctly aligned.
Care was taken to not tighten the carrier bolts all the way. It’s a new carrier, and we needed to set it up properly with shims included in the Omix-ADA kit, which meant we would be taking it out and putting it back in several times.
As we’ve said before, unless your have experience and the right tools, you should have an expert set up your differential gears. Backlash is being set here with this gauge.
In addition to backlash, pinion gear depth on the ring gear must be set as well. The guys at Precision used the rebuild kit’s included gear marker compound to set pinion depth.
To check pinion depth, the marker compound was used on the ring gear and then the gear was rotated through the pinion. The wear pattern was checked against a chart included in the rebuilt kit. Incorrect pinion depth can contribute to increased highway noise and accelerated wear.
Once the differential was set up properly, it was time to install the axle locker sensor in this threaded fitting in the forward portion of the differential.
This is the TJ Rubicon axle locker sensor (PN 52104610AA). It’s similar to the JK sensor, but they aren’t compatible. JK sensors are readily available from several different companies, but we found the TJ sensor at Mopar Parts Overstock. Even if the original sensor looks good, you may want to replace it anyway—our old sensor lasted just a few miles, and we had to replace it.
The little “hat” on the end of the sensor is placed under the actuator plate edge, which, when activated, pulls out the sensor and activates the locker indicator light on the dash.
We carefully reinserted the carrier assembly so that the sensor and actuator plate were mated properly. The carrier was held in place until all four bolts were once again tight.
After testing the air locker and the sensor, we torqued the carrier mounting bolts to factory specifications. Since the ring-and-pinion set was not changed, we didn’t need to break in the new carrier and could use normal gear oil.
Using the rebuild kit’s included silicone gasket maker, we applied a bead to the differential cover.
We made sure the cover’s edge was thoroughly and thickly covered and then carefully torqued all the cover bolts according to factory specifications.
The carrier change-out was finalized by reinstalling the axles, brake assemblies, and tires.