Beefy Model 35-C Axleshaft - Jp Magazine

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

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 of the Jeep Wranglers, Cherokees, Comanches, and Wagoneers.

154 9901 Beefy Model 35 C Axleshafts bullet Proof Axles Photo 30730534

Except for the notorious 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 has addressed the major weakness of the unit: 27-spline axleshafts, which are notoriously weak. 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, which places a retained bearing at the axle end, which eliminates the loss of the tire and wheel, but doesn't make the shaft any stronger.

But 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 over 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! And these aren't just cut-down and splined aftermarket jobs. These new axles feature rolled splines, just like the factory does it. Induction-hardening also makes the shafts far stronger and durable, and the improved tapered-shaft design gives the axle more resilience.

154 9901 Beefy Model 35 C Axleshafts superior Axle Set Photo 30730540

The larger diameter and spline count also mean a different differential is needed to accept the new axleshaft, so Powertrax has developed a special LockRight locker, available only from Superior Axle and 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 LockRight come installed on the carrier, and new axle bearings and seals are also included. DriveTrain Direct has even started development of 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 and Gear products, to check out the installation of the new setup, which is relatively painless to install. Complete instructions come with the kit, and for the most part 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 and Gear's replacement 30-spline axles are 1.31 inches in diameter, as opposed to the stock 1.18-inch 27-spline. Superior 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, since 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 and wheels and the brake drums. The cover is pulled, and the oil is drained and properly recycled. Slide the axleshafts inboard, which allows the C-clips to be pulled out with a small magnet. With a few 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, a puller is used 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 are removed after marking them so that they can be replaced in the same position. Long prybars are handy for removal of 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 installed the same way. With the old carrier assembly out of the housing, the ring gear is removed and cleaned. The new carrier assembly has the LockRight locker and the carrier bearings and races installed. The old ring gear is bolted on to the new assembly with new carrier bolts. Use Loctite to retain them. After a thorough cleaning of the axle housing, The carrier is placed back in the housing with the original shims on the same side they came from. Some forcing may be necessary because the bearings are preloaded when forced into the housing. A soft-faced or dead-blow hammer is very useful during installation. 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. Gear-marking compound is used 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. A special installer is used to install the new roller bearings in the ends of the axle tubes. The bearings are lubed from the axle centersection with gear oil, so no inner axle seals are needed. The outer axle seals are installed in the same manner as the bearing. The new axleshafts are slid into the housing until the splines fully engage the LockRight. The axleshaft is 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 part to install, and even so, it's relatively easy. The cross pin is removed from the LockRight, which allows the two center drivers to come together. With the axleshaft pushed all the way inboard, the C-clip is dropped in between the clutch and driver and, hopefully, into the groove on the end of the axle (arrow) . Once engaged, the axle is pulled out to seat the C-clip in the recess of the LockRight. Check for a small amount of endplay and free rotation. With both axle C-clips installed, the cross pin is placed back through the case and LockRight. The pin has two different size holes 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 are 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 LockRight comes partially assembled in the carrier, only the springs need to be installed. An inner and outer spring are held together, then carefully slid into the recess on the LockRight. Four of these spring assemblies are placed in the LockRight, which completes the installation. 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 by running them gently and allow them to cool, e.g., a drive around the block then letting the vehicle sit.