First appearing on the Mustang in 1986, the venerable 8.8-inch solid rear axle (rearend) has had a significant role in the Mustang performance world ever since. A favorite of enthusiasts, the 8.8 has taken Mustang owners for fast passes down the drag strip, and around corners on some of the fastest tracks in the country.

From 1986-2004, the 8.8 remained pretty much the same. Many builders have come up with tricks over the years to fortify these housings and improve them for drag racing, but there are still at least two issues facing any enthusiast building an 8.8 today. One is age, with the newest of those 86-2004 housings now being over 10 years old. The other is the inherit weaknesses that were part of the original 8.8 housing design. The 8.8 housing had to be mass produced in a cost effective manner. It also had to do its part in complying with new vehicle noise, vibration, and harshness (NVH) standards.

Since the favorite 8.8 of many enthusiasts has been out of production now for the better part of a dozen years, finding one that’s in perfect working order, and is able to meet the demands of a variety of builds is becoming more difficult. There’s also the additional costs of fortifying the housing for higher performance, and changing things like the axle bearing retention for better performance.


Moser has recently given us a sneak preview of its upcoming new 8.8-inch rearend. This housing picks up from where the original 8.8 design left off, and offers enthusiasts a viable alternative to building a used housing, and customizing it. “This is the largest reintroduction of a reengineered performance rearend component since Moser Engineering reintroduced the Moser 12-Bolt back in 2000,” says Moser’s Jeff Anderson.

The new Moser unit is constructed from the same nodular steel that Moser utilizes in its Moser 60 and Moser 12-Bolt assemblies. The improvements don’t end with the introduction of better steel. Moser’s engineers redesigned the 8.8 to add additional material and webbing where the OEM 8.8 was lacking. Larger than OEM oversized main caps also help to distribute more of the load to support covers. This allows the cover to take on additional stress and should give the differential less deflection under high torque loads.

An area the OEM 8.8 has always needed additional support has been the axle tubes. Small, and somewhat thin in their wall thickness, we’ve seen axle tubes welded to the differential housing, and various methods of reinforcement over the years. The Moser 8.8 eliminates much of the OEM 8.8’s shortcomings here as well. The Moser 8.8 features 3-inch diameter axle tubes made from 0.25-inch thick DOM steel tubing.


Another popular modification to 8.8s has long been to modify the axle housing ends to accept larger press-on axle bearings, changing the axle retention system to something similar to a Ford nine-inch. Moser will give customers the option of going this route or keeping OEM-style C-clip axle retention.

Anderson says Moser has also improved lubrication inside the housing. The Moser 8.8 will have improved oiling of the bearings and cooling of the gear set. Both should increase the life of the internal components.

Fitment will be available for any ’79-’04 Mustang, as well as street rods and kit cars. “These are already being lined up for use by a few small volume companies for their production units in street legal applications,” says Anderson.

Moser will offer the new 8.8 as an empty housing, a housing with axle package, or a complete Muscle Pack crate rearened. Anderson says the new Moser 8.8 should be ready to ship sometime in the first quarter of 2016.