Bulletproof Dana 35-C Axles - 4-Wheel & Off-Road Magazine

Rick Péwé Editor-in-Chief, 4Wheel & Off-Road Photographers: Rick Péwé

The Dana Model 35-C axle has been around for quite a while in various forms and applications. The most common is the C-clip design found in most Jeep Wranglers, Cherokees, Comanches, and Wagoneers.

131 9902 Bulletproof Dana 35c Axles superior Axle Kit Photo 31615105

Except for the infamous C-clip itself, the rearend gives quite adequate service to the majority of Jeep owners, especially in stock form. But start adding bigger tires and lower gears, and the little axles don't perform as expected.

Many aftermarket companies have produced options and upgrades for the 35-C, including lockers, different gear ratios, and disc brakes. But until recently, no one had addressed the major weakness of the unit: 27-spline axleshafts. A broken axleshaft on these units means the tire and wheel leave the Jeep while in motion, since only a C-clip inside the differential retains the axle. ARB developed and markets a C-clip eliminator kit that places a retained bearing at the axle end to eliminate the loss of the tire and wheel, but it doesn't make the shaft any stronger.

If you have a stock axle under the rear of your Jeep, fear no more. Superior Axle has just introduced a 30-spline, high-strength axle kit that's more than 35 percent stronger than the factory unit. The increase in spline count from 27 to 30 comes with a size increase in diameter to 1.31 inches-the same as a Dana 44. These new axles aren't just cut-down and splined aftermarket jobs; the axles feature rolled splines just like the factory. Induction-hardening also makes the shafts far stronger and more durable, and the improved tapered-shaft design gives the axles more resilience.

The larger diameter and spline count also means a different differential is needed to accept the new axleshaft, so Powertrax has developed a special Lock-Right locker, available only from Superior Axle & Gear, to fit the beefier axleshafts. To further strengthen the whole shebang, a new replacement carrier is specially modified by machining and heat-treating critical areas to increase the strength and durability of the stock carrier. The new carrier bearings and Lock-Right come installed on the carrier, and new axle bearings and seals are also included. DriveTrain Direct has even started developing a truss for these axles, which have a habit of bending under severe use.

We recently went to DriveTrain Direct, a leading distributor of Superior Axle & Gear products, to check out the installation of the new setup, and it was relatively painless to bolt in. Complete instructions come with the kit, and for the most part, it can be done in your own garage with the axle still in the vehicle. Follow the photos and see how easy it is to really beef up your 35-C.

PhotosView Slideshow Superior Axle & Gear's replacement 30-spline axles are 1.31 inches in diameter, as opposed to the stock 1.18-inch 27-spline axles. Superior Axle & Gear is the light-duty division of Foote Axle and Forge, which has been making axles since 1936. The axles feature rolled splines, which are far stronger than cut splines because the rolling process increases torsional strength, fatigue resistance, and wear resistance. The C-clip, which retains the axle, is located inside the differential carrier. These photos were shot with the housing out of the Jeep, but the kit can be installed with the housing in the vehicle. With the Jeep on jackstands, remove the tires, wheels, and brake drums. The cover should then be pulled, and the oil drained and properly recycled. Slide the axleshafts inboard, which allows the C-clips to be pulled out with a small magnet. With some special tools and a little experience, the axle upgrade kit can be installed in a few hours. After the axles are slid out of the housing, use a puller to remove the outer axle seal and axle bearing. New Torrington axle bearings and National seals are included in the kit and must be used with the new axles to keep the warranty in effect. The carrier bearing caps can be removed after they've been marked so that they can be placed back in the same position. Long prybars are handy for taking out the carrier assembly. Carrier bearing preload and backlash shims are located on the outside of the bearing races against the housing. They must not be damaged during removal and must be kept separated side to side so they can be put back the same way.
With the old carrier assembly out of the housing, unbolt and clean the ring gear. The new carrier assembly has the Lock-Right locker, carrier bearings, and races already in place. Bolt the old ring gear onto the new assembly with new carrier bolts. Use Loctite to retain them. After a thorough cleaning of the axlehousing, place the carrier back in the housing with the original shims on the same side they came from. Some force may be necessary because the bearings are preloaded when pressed into the housing. A soft-faced or dead-blow hammer is very useful for this step. If your Jeep is equipped with antilock brakes, the tone ring needs to be removed from the old axle and installed on the Superior set. New tone rings are also available if the old ones can't be salvaged. Notice the screw-in studs, which make replacement a snap. The extra holes in the flange are there if you wish to use the standard press-in stud. Use gear-marking compound to check the pattern of the gear teeth, which should be the same as before. If the pattern or backlash is not within specifications, pull the assembly and adjust the shims until an acceptable pattern is produced. Use a special installer to press the new roller bearings in the ends of the axletubes. The bearings are lubed from the axle centersection with gear oil, so no inner axle seals are needed. Install the outer axle seals in the same manner as the bearing. Slide the new axleshafts into the housing until the splines fully engage the Lock-Right. The axleshaft should be specially heat-treated through induction-hardening, with special attention paid to the bearing surface for long life and durability. The C-clip installation is the most difficult step, but even so, it's not too hard. Remove the cross pin from the Lock-Right to allow the two center drivers to come together. With the axleshaft pushed all the way inboard, drop the C-clip between the clutch and driver and into the groove on the end of the axle. Once engaged, pull out the axle to seat the C-clip in the recess of the Lock-Right. Check for a small amount of endplay and free rotation. With both axle C-clips in place, slide the cross pin back through the case and Lock-Right. The pin has two holes of different sizes in the opposite ends for use with two types of carriers. Make sure the proper hole is aligned with the carrier you have. The lock pin on most 35-C axles is the screw type, as shown here. Older, non-C-clip axles generally use a roll pin, but some variation does exist. Tighten the screw-in lock pin after using Loctite on the threads. If this pin comes loose, the shaft can come out and destroy the innards. Since the Lock-Right comes partially assembled in the carrier, only the springs need to be installed. An inner spring and an outer spring need to be held together then carefully slid into the recess on the Lock-Right. Place four of these spring assemblies in the Lock-Right. The final step is to silicon the cover in place and add standard hypoid gear oil. As with any new bearing or gear assembly, break in the parts by running them gently and allowing them to cool by driving around the block and then letting the vehicle sit. PhotosView Slideshow