Moser made upgrading any rearend...
Moser made upgrading any rearend simple with its setup kits. It includes the differential bearings (cups and cones), pinion bearings (cups and cones), pilot bearing, pinion support shims, adjustable pinion collar, pinion seal, nut, ring gear bolts, and even the gear-marking compound to complete the build.
Rodriguez installed our stock...
Rodriguez installed our stock pinion depth shim (located between the pinion bearing and the pinion head), pressed on the pinion bearing, and installed the crush sleeve. Before it went into the housing, we applied ample white grease to the pinion surface. To lock it in for final, we added the factory yoke and fastened it on with the supplied pinion nut.
With the old components removed...
With the old components removed from the housing, Rodriguez cleaned the inside of the case with solvent to remove any debris and material before the new bearings were installed. He then added the new pinion bearing races, bearings, and seals to the 10-bolt.
The Detroit TrueTrac was the first helical gear (no clutches) differential ever introduced into the aftermarket as an Eaton brand. In short, the patented design of the parallel axis planetary helical gears provides a quiet, automatic splitting of torque. It performs like an open differential under normal driving conditions and automatically transfers torque to the wheel with better traction. This limited-slip system responds instantly to torque feedback, anytime, at any speed.
Using a hydraulic press, Rodriguez...
Using a hydraulic press, Rodriguez applied pressure to the old pinion and was able to separate the factory bearing. We removed the stock pinion depth shim (located between the pinion bearing and the pinion head). Since the stock pinion depth shim is the correct thickness, it can be reused with the new components.
To install our new ring gear...
To install our new ring gear to the Detroit unit, we used the new bolts supplied by Moser in the setup kit. We applied red Loctite to the threads and torqued in a cross-tightening pattern to 75 ft-lb. Note: New Moser carrier bolts are lefthand threads.
We gently lowered the new...
We gently lowered the new carrier assembly into the housing and placed carrier shims between the carrier bearings and the rearend housing. Their job is to place a preload on the carrier and keep pressure against the bearings while the shim’s thickness on both sides also determines the amount of ring-gear backlash. It’s important to note that the backlash can be adjusted by changing the shim’s thickness side for side. To decrease backlash, we could increase the thickness on the left side while reducing the thickness an equal amount on the right side. To increase backlash, we could do the opposite. With the carrier in, we torqued the main caps to 65 ft-lb and made sure it spun freely in the housing. Note: The carrier assembly may have to be installed several times before the correct backlash is determined.
Moser’s gears are available for nearly any application and are CAD, CNC machined, and computer-control heat-treated to ensure the highest-quality product. Moser even offers a ring gear lightening program (add $100 to any set of gears) for serious racers to save precious rotation weight. The process involves machining a smooth radius on the outside of the gear and can save anywhere from 0.5 to 2.5 pounds. In our case, we ordered a set of Moser’s street/strip gears with a 3.73:1 setup.
To check we still had the...
To check we still had the correct backlash, we placed a dial indicator onto the ring gear and following the factory specs (0.005-0.010 inch) we determined our housing’s backlash was well within range at 0.007 inch.
Proper ring-and-pinion life...
Proper ring-and-pinion life begins with establishing the correct gear pattern. Identifying the wear pattern will signal if the backlash between the ring-and-pinion needs to be adjusted by swapping out different carrier shims. To do this, Rodriguez applied gear-marking compound onto the ring gear to identify the wear pattern. Spinning the gears produced a wear pattern that illustrated a majority of the gear contact was in the center of each tooth—exactly where it needed to be. Contact at the corners or edges of the teeth could break them and the backlash would have to be readjusted.
Once the new Moser axles are...
Once the new Moser axles are installed, we replaced the C-clips and added the axle spacer (replaces factory pin). Then, we installed the retaining cylinder and snap ring, making sure it had completely engaged with the groove.
A performance cover is one...
A performance cover is one of the single best things you can do to strengthen a 7.5- or 8.5-inch 10-bolt rearend. An integrated cap girdle helps stop gear deflection under load, which is caused by the main caps “walking”. To seal the deal, we bolted the custom Moser cover onto the housing, snugged the Allen studs against the main caps, and torqued them to 5 ft-lb. Then, we finished off the nuts with 10 ft-lb.
The Grab Bag
||30-spline axles (291/2 length)
||Setup kit/axle bearings, seals
||75W90 rearend fluid
Getting the rearend back in the Nova was a snap. We made sure to fill the rearend with 3 quarts of Synthetic Royal Purple 75W90 gear oil (for limited-slip gears) and put some miles on the gears before any competition. While at this year’s Goodguys Del Mar event, we noticed the Nova’s characteristics and personality have completely changed since our install of the Moser components; it’s like driving a new car. Wasted power that used to be directed to one spinning tire is now equally split between two. This translates into faster times through the cones and makes more use of the available power. We can even have a little fun in the turns now by sliding out the back end with some extra throttle. Plus, burnouts have become a lot more interesting. CHP