American Axle Manufacturing Upgrades

In 1992 General Motors opted to sell off a portion of its factories, with five of them purchased and put into production under the new company title of American Axle and Manufacturing. What had previously made GM parts now makes a large variety of axles and components found in many vehicle makes and models. AAM axles are now found in everything from the Chevy Colorado and Silverado to the Ram 2500, 3500, and Power Wagon. AAM also makes disconnectable sway bars like those in the Wrangler and Power Wagon, oil pans, and transfer cases, as well as other powertrain, drivetrain, driveline, and chassis components.

This month check out what is found in the front of Ram (Dodge) heavy-duty trucks, and next month we’ll concentrate on the rear AAM axle options. The AAM 91⁄4-inch front is most common under Ram 2500/3500 trucks, but it is also found in an IFS version under GM 3⁄4- and 1-ton trucks. We spent a few days upgrading to some stronger, more efficient components from Dynatrac, ARB, and Carli suspension.

Power Wagon Axles
If you are thinking a set of AAM axles might be right for you, let us also remind you that Mopar offers new Power Wagon axles as well. These axles have a 91⁄4 front ring gear and 101⁄2 rear, both with 4.56:1 gearing and selectable locking differentials. The axles come with all factory brackets for a front four-link with track bar and rear leaf spring suspension as well as disc brakes front and rear and an 8-on-61⁄2 wheel bolt pattern. These are available from your local Jeep/Dodge/Ram dealership’s parts department (front, PN P5155087AB; rear, P5155088AB). They retail for roughly $7,400

American Axle and Manufacturing makes a wide variety of components for original equipment manufacturers (OEMs), from axles and transfer cases to selectable sway bars. For example, every GM or Ram (Dodge) 3⁄4- and 1-ton 4x4 uses AAM axles front and rear, as do most Tahoes, Yukons, Denalis, Avalanches, Escalades, and this Colorado.
American Axle and Manufacturing makes a wide variety of components for original equipment
The front AAM 91⁄4 axle found its way under Dodge heavy-duty trucks in 2003. On our Ram 3500 it isn’t bad in stock form. The axleshafts are 33-spline 1.37-inch diameter, and as of 2012 it now uses a massive 1555 series U-joint, but we still opted for some Dynatrac upgrades.
The front AAM 91⁄4 axle found its way under Dodge heavy-duty trucks in 2003. On our Ram 35
One complaint of many new truck owners is the lack of fuel economy. The AAM axle uses a unit bearing hub that causes all the axleshafts to spin constantly. This unit bearing can also fail, causing further damage. Though a unit bearing is simple and easy to replace, Dynatrac offers a solution to these concerns.
One complaint of many new truck owners is the lack of fuel economy. The AAM axle uses a un

The Dynatrac Free-Spin replacement hub kit replaces the unit bearing with a knuckle-mounted spindle and a more conventional-style rebuildable hub. This allows the truck owner to service the hub bearings. The Free- Spin kit is optioned with a set of selectable hubs (in our case a set of Dynatrac’s own Dynaloc hubs), so the axleshafts only spin when locked in.
The Dynatrac Free-Spin replacement hub kit replaces the unit bearing with a knuckle-mounte
The Free-Spin installation requires the almost complete disassembly of the AAM front axle. We took this opportunity to upgrade other components as well as replace some worn parts. Removing the brakes, unit bearings, and axleshafts is required, but we went even further in disassembly.
The Free-Spin installation requires the almost complete disassembly of the AAM front axle.
At the top and bottom of each steering knuckle is a ball joint around which the knuckle steers. These ball joints are prone to wear after many miles, especially with tires larger than stock, a scenario our Ram 3500 has already met.
At the top and bottom of each steering knuckle is a ball joint around which the knuckle st

We removed the old ball joints to replace them with a set of Dynatrac’s ball joints. The Dyntrac joints are stronger due to heat-treated billet bodies and chromoly stems. Like the Free-Spin hub kit, the Dynatrac ball joints are also rebuildable and fully greasable in the truck.
We removed the old ball joints to replace them with a set of Dynatrac’s ball joints. The D
With the axle torn down for ball joints and the Free-Spin kit, we pulled out all the stops and added a front selectable ARB Air Locker. This required pulling the factory differential and swapping the ring gear onto the ARB. We also needed to drill a hole through our housing to run the air line for actuating the locker. The ARB will give us positive drive to both wheel ends when locked in via air pressure.
With the axle torn down for ball joints and the Free-Spin kit, we pulled out all the stops
Upon removal of our original carrier bearings we discovered a serious flaw in one of the races. This factory fluke was luckily discovered and both carrier bearings were replaced before major carnage occurred.
Upon removal of our original carrier bearings we discovered a serious flaw in one of the r

The Free-Spin kit replaces the short stub shaft with a new longer one. The later-model (’10-plus) Ram/Dodge trucks now use a larger 1555 steering U-joint (AAM PN 68004853AB) for additional strength and steering angle.
The Free-Spin kit replaces the short stub shaft with a new longer one. The later-model (’1
Our manual transmission truck has 3.73 axle gears, and we run 35-inch tires. The common idea would be to change to a lower gear ratio since we run a taller-than-stock tire. We opted to stay with the 3.73s when upgrading to the Air Locker, as the Cummins diesel has good torque and this keeps the engine revs lower on highway jaunts.
Our manual transmission truck has 3.73 axle gears, and we run 35-inch tires. The common id
Dynatrac always pressure-tests its Air Locker installations prior to buttoning up the differential housing. This safeguards against leaks and activation issues down the road, or trail.
Dynatrac always pressure-tests its Air Locker installations prior to buttoning up the diff

One benefit we really like is that AAM uses bearing cap adjusters in many of its axles. This greatly improves gear installation, as backlash can be easily adjusted instead of shims needing to be pulled and replaced.
One benefit we really like is that AAM uses bearing cap adjusters in many of its axles. Th
The Dynatrac Free-Spin hubs have the proper tone ring pressed on so the Ram ABS computer doesn’t show any faults. The hubs use bearings that can be removed, cleaned, and regreased, which should be done approximately every 40,000 miles.
The Dynatrac Free-Spin hubs have the proper tone ring pressed on so the Ram ABS computer d
The new Dyntrac ball joints were pressed into place and the factory steering knuckle reassembled. We consider this truck to be our do-all machine, whether towing a heavy trailer or exploring desert dirt roads, so we needed parts we could depend on day and night. The ability to service our truck’s joints and hubs gives us the responsibility for that reliability.
The new Dyntrac ball joints were pressed into place and the factory steering knuckle reass

The new Free-Spin spindle bolts onto the knuckle in place of the unit bearing. The spindle is a Dynatrac-specific part, but the bearings are available through most parts houses for ease of service if replacement is needed. Note the tab at the top of the spindle for the speed sensor.
The new Free-Spin spindle bolts onto the knuckle in place of the unit bearing. The spindle
Compared to the unit bearing, the Free-Spin hub has the same mounting surface so the tires do not stick outside the fenders. The new hubs do stick out farther, which can risk trail damage, but the hub also has a larger spread on the bearing placement for added strength.
Compared to the unit bearing, the Free-Spin hub has the same mounting surface so the tires
The Dynatrac DynaLoc hubs are some of the best on the market and offered us the ability to unlock the front end for additional fuel economy. We actually noticed a 1-mpg gain in highway mileage from simply unlocking the hubs. These hubs are made in the USA and use heat-treated chromoly components for strength. We also like that in the rare occasion of a failure the hubs are designed to revert to the locked position, a benefit if you’re stuck on a trail.
The Dynatrac DynaLoc hubs are some of the best on the market and offered us the ability to

With our new front AAM axle components inside, we opted for a substantial upgrade in protection as well. We bolted on a differential guard from Carli Suspension. The guard easily attaches over our factory cover by just unbolting the bottom seven bolts and bolting it on. We didn’t need to drain the gear oil.
With our new front AAM axle components inside, we opted for a substantial upgrade in prote
Carli has a full line of AAM axle upgrade parts, including weld-on axle trusses and ball joints. Carli also offers a full line of Dodge truck suspensions for lift and off-road performance.
Carli has a full line of AAM axle upgrade parts, including weld-on axle trusses and ball j
Mercenary Offroad is developing a line of AAM axle diff covers. These covers are fabricated from 3⁄8-inch steel and replace the factory cover.
Mercenary Offroad is developing a line of AAM axle diff covers. These covers are fabricate

SOURCES
Dynatrac 7392 Count Circle Huntington Beach CA 92647 714-596-4461 www.dynatrac.com	Carli Suspension N/A AK 714-532-2798 www.thecarlisuspension.com
Mopar P.O. Box 21-8004 Auburn Hills MI 48321 800-992-1997 www.mopar.com	Mercenary Off Road Sun Valley CA 91352 www.mercenaryoffroad.com