Step By Step
This CJ has the typical narrow-track Dana 30. Since the vehicle is just starting to be used on more challenging trails, the mild and affordable upgrade to Superior Axle & Gear axleshafts makes sense. If hardcore is your plan, skip these ’shafts and save your money for a complete Dana 44 or bigger axle. We went to Drivetrain Direct to photograph and gather tips as they installed the new axleshafts.
To get to the axleshaft, the hub must be removed. This is a two-piece hub so the dial comes out first, then the snap ring from the end of the axleshaft can be removed. Next the bolts retaining the base of the hub can be removed and the hub body comes off.
There are two nuts inside the wheel hub which retain it on the spindle, and a metal plate between the two has tabs bent over to hold the top nut in place. Bend these tabs out of the way. You’ll need a special hub nut socket for a Dana 30 to remove these nuts. When you pull the rotor and wheel hub off, the outer wheel bearing will be loose. Keep a hand over the opening of the wheel hub to catch this bearing.
Next the brake caliper is removed. This has a clip on the caliper retained by a bolt. The clip can be pushed out with a screwdriver and hammer after the bolt is removed. With the caliper and rotor removed, you can unbolt the spindle and brake baking plate. You will probably have to use a plastic hammer to loosen the spindle from the knuckle.
Check the bearing surface on the spindle for excessive wear and find replacements if necessary. Warn offers new spindles for - CJs with disc brakes.
Now you can pull the old axleshaft out of the housing. You won’t be using any of this assembly, but it’s a nice idea to put new U-joints in and keep them as spares.
The stock Dana 30 axleshafts use Spicer 5-260X (left) while the Superior axles come with Spicer 5-297X U-joints. The difference in cap diameter is 1.063 inches versus 1.188, which may not sound like much. The real strength difference is in the larger diameter of the trunnions and cross-shafts. They offer both the sealed type and those with grease fittings. There are plenty of opinions on strength versus longevity, so you can choose which ever you want.
The new Superior axleshafts (top) from Drivetrain Direct come assembled with Spicer 5-297X U-joints. These axles are of the same quality as the OE pieces and feature rolled (not cut) splines.
The most difficult part of installing the new axleshafts is removing the old inner-spindle bearing. It’s a very thin bearing cage, which is hard to get a good grip on to knock out of the spindle. Technically you don’t have to replace this bearing, but the kit comes with a new one and you’re already there, so do it.
The spindle and backing plate go on in the opposite order you removed them. The hubs on this Jeep were hammered and full of mud, so a Warn front-hub conversion kit from Drivetrain Direct was installed. This upgrades the wheel hub and hub body to the stronger internal style. New bearings and wheel studs from Drivetrain Direct were installed in the wheel hub.
The new wheel hub simply slides onto the factory spindle. The conversion kit comes with new locknuts and a slotted washer which goes between the two nuts. The nuts require a Dana 44 hub nut wrench. Tighten the first nut to factory specs, slip on the washer, and tighten the outer nut as tight as you can with hand tools.
The hubcap installs with the Allen screws provided with the kit. There’s a small O-ring for each screw which helps keep water out of the hub assembly. Check the operation of the hubs and you’re finished.
Pow. You know that sound--it comes from the Dana 30 under the front of your CJ. But was it the hub exploding, the steering U-joint failing, or the axleshaft snapping in two? If you have stock hubs, you've answered your own question. If not, odds are you just wasted a U-joint.
The Dana 30 uses 5-260X steering joints that are OK for most stock Jeeps and mild off-roading. But add stress like 33-inch tires, lockers, gears, and maybe some more horsepower and you've pulled the pin: it's only a matter of time before explosion.
Avoiding this scenario isnt too difficult, but it can be costly. A very affordable option is Superior Axle & Gear upgrade axles for Dana 30s. These are made to the same quality specs as the original axleshafts, but accept 5-297X U-joints used in 1/2- and 3/4-ton truck Dana 44s. Drivetrain Direct offers these axleshafts for 1972-1986 CJs in kits that include the inner and outer axles assembled, with your choice of sealed or serviceable Spicer U-joints, inner spindle bearing and seal, and an axle snap ring. For about $200 per side, the upgrade may leave enough cash in your pocket for a lunchbox locker (which would be easy enough to add when youre changing axles) or those aftermarket hubs you know you need.