Dodge Front Axle Upgrades To Handle Serious Power
Fixing The Front-Axle Fuse
Weak links. Every truck has them. They’re the part in the system that’s just a bit more fragile than the rest. Some become apparent when you add extra power. Others make themselves known with age. The AAM 925 front axle in the ’03 to ’10 Dodge 2500 and 3500 trucks is a great example.
Overall, these are pretty good assemblies. But they use unitized wheel bearings (commonly called unit bearings), which become a weak link over time. It’s natural for all bearings to wear, but when these unit bearings fail, the front tire can part ways with the truck. If you’ve added larger tires or used wheels without the correct offset, you’ve shortened the life expectancy of the stock unit bearings considerably.
The other big weak link in these front-axle assemblies is the 1485-series steering U-joints. The stockers are OK if you haven’t added power, larger tires, or a locking differential but do all three and you’ll find their limit pretty soon.
We decided to be proactive and upgrade both the steering joints and the unit bearings in our ’03 Dodge Ram 2500. The truck has moderate power upgrades and stock tires. With 90,000 miles on the odometer, this Dodge’s unit bearings were starting to make noise. That means the pin had been pulled on the grenade, and it was just a matter of time before the unit bearings gave up. We took the truck to Unlimited Offroad Centers in Fenton, Michigan, to install a SpynTec hub conversion kit that replaces the non-serviceable unit bearing with a fixed spindle, hub, and bearing assembly. We also upgraded the axleshafts with an RCV Ultimate CV axle set. The RCV shafts are made from aircraft-quality steel and the CV joints are engineered to handle serious abuse, while eliminating the crow hop you experience when turning corners in four-wheel drive. The new axleshafts and CV joints are so strong that RCV offers a you-break-it, we-replace-it warranty. We’ll give it our best shot.
Tips From The Pros
• The kit includes Mile Marker lockout hubs. Matney coats the inner workings of the hubs with lithium grease prior to installing them. They come with a wrench, which should be used to keep from overtorquing the Allen bolts. Make sure they operate smoothly. If not, something is amiss.
• Our truck has factory wheels on it, so the last step of our install was to fit the original wheel center cap to the hubs. We thought about leaving the caps off, but the hubs look huge without a cap to help take up some of the length. Eric used a 4½-inch hole saw to cut the original plastic caps.
• The RCV axleshafts have a grease fitting that requires a needle-type tip on your grease gun. They should only require greasing a couple of times a year. RCV sells a special grease that should be used in its joints.
• We can now lay on the throttle in four-wheel drive without cringing and waiting for a loud pop. The shafts steer smoothly, as promised, and we’re looking forward to an extra mph or two with our front hubs unlocked.