Grappling With Chromoly
If you drive your 4x4 hard enough, you’ll find the weak points on the vehicle. While nobody likes breaking down on the trail, it’s an inevitable reality for many. Preventative maintenance is one way to keep from being stranded, but your trail prep shouldn’t end there. On vehicles such as the ’97-’06 Jeep Wrangler TJ, a major weak link can be found with the Dana 30’s front axleshafts.
In stock form, the 1040 steel ‘shafts are plenty adequate. However, when you add in heavier and oversized tires into the equation, along with a front traction aid such as a differential locker, the ‘shafts and U-joints are known to fail. Our friend's 2000 Jeep Wrangler TJ is equipped with a 4.5-inch BDS long-arm suspension, 35x14.50R15 Nitto Mud Grapplers and an Aussie Locker in the front end. This combo makes for great traction on the trail but can easily equate to ‘shaft failure.
To increase his Dana 30’s odds against trail failure, he opted to upgrade the stock axleshafts with a replacement set from Alloy USA. The Alloy shaft kit (SKU: 12148) includes both inner and out axleshafts, along with serviceable Alloy USA X-joints.
The stock Dana 30 axleshafts are a 1040 carbon steel. Alloy USA uses a 4340 chromoly, which equates to a 40-percent strength increase over stock. Both inner and outer ‘shafts are 27-spline, so you can reuse your stock unit bearings, and in this case, Aussie Locker.
In place of a stock U-joint, Alloy uses its X-joint, which is fit with needle grease fittings at the top of each cap. The cold-forged steel composition is comprised of chromium, molybdenum and nickel alloy. Not only is this joint significantly stronger than the OE version, it’s also easily serviceable.
Since the X-joints come separate from the ‘shafts, you’ll need to assembly the set. You’ll start by unbolting the grease fitting from the caps, then pulling each cap off the body of the joint.
We like to place extra grease inside of the cap to make sure the needle bearings stay in place during the install. It’s also helpful to add a swipe of grease inside the yoke ears.
To install the caps, all you need is a hammer and a steady hand. Be sure to keep pressure on the body of the U-joint in the direction of the cap you are hammering in.
Your final step for the ‘shaft assembly will be to install the half-circle clips on the caps. This is what’s known as an inner clip, versus on outer style that would go at the top of the cap.
To install the new ‘shafts, you’ll first support your Jeep’s front axle, then remove the tire. The next step will be to break the axleshaft nut free. To do so, you’ll need a 36mm socket and impact gun. If you don’t have an impact, we suggest placing the tire back on the vehicle with the wheel’s center cap removed. Place the vehicle weight back on the tire, then use a breaker bar and extension to break the nut loose.
With the axle nut removed, make your way to the two brake caliper bolts. You’ll remove both bolts and set aside the caliper. After this, you can pull off the brake rotor.
The ’97-’06 Jeep Wrangler TJ Dana 30 front axle uses a unit-bearing design. This setup serves as the front axle’s wheel bearing and hub assembly. It’s secured to the steering knuckle via three bolts, which require a 12-pt, 13mm to remove.
Once you unbolt the unit bearing from the steering knuckle, you can pull it off the axle. With the unit bearing removed, you can slide out the stock axleshaft assembly.
To install the new Alloy USA axleshaft set, grab the correct side and simply slide it into the differential housing. We recommend putting a small dab of great on the ‘shaft end going into the diff. This will help prevent you from possibly tearing the seal.
Reassembly is straight forward from removal. Be sure to put a new cotter pin in the stub ‘shaft once you’ve cinched the axle nut down.
For an added bonus, we put together a quick video highlighting the install process.