J20 Axle Rebuild & Upgrade

This was by far the most time consuming and expensive project to date on my J10. I initially wanted to be able to beef up my axles without having to do extensive modifications on both the front and rear axle. I wanted direct bolt in axles and the best axles for this were the axles from an 1980 thru 1988 3/4 ton Jeep J20. In January, 2005, I posted a "Wanted" ad on IFSJA seeking axles from a 80 thru 88 J20 truck. Thinking it may take awhile, I was surprised to get an email the next day from another IFSJA member "Dave" who told me that he had a pair of axles off an 88 J20 for $200. But, he went on to say that the axles were still on the truck and the truck was non-running. So, I grabbed my brother-inlaw and his trailer and made a road trip to Chicago to retrieve the J20.

Here are the pics of the 1988 J20

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j20rear.jpg (81076 bytes)

I parted out most of the parts and made some money to put towards the axle rebuild. Did I say axle rebuild? Yep. My original intention was to just literally take the axles and swap them into my J10. But, I soon discovered that the front balljoints were shot, seals were leaking, and the axles were as rusty as they could possibly be coming from a northern truck. Here are some pics of the axles after I removed them from the J20.

The night I finished removing the axles.

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Rusty front axle...With crabby Son.

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Rusty front passenger side hub assembly.

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Rusty rear D60 axle.

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Rusty backing plates on the D60.

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OK...Enough of the rusty axles. Let's get down to the nitty gritty.

I finally came to the conclusion that I was going to rebuild the axles with all new bearings, seals, swap in 4.10 gears, and install a Detroit Locker in the rear D60 and install a Detroit TruTrac LSD in the front D44HD.

The first axle to get rebuilt was the D60. As rusty as it was, all nuts and bolts came out without breaking. When I installed the new 4.10 ring, pinion, and Detroit locker, it went together in two evenings starting from the original pinion depth. After removing and reinstalling the DL carrier several times to add and remove shims on both sides, I finally came up with the below pattern with .005 of backlash.

pattern1.jpg (42782 bytes)

I also replaced the D60 cover with the rubber plug with a thick cover with the standard screw in plug. After getting all the componants together, I wire brushed the entire axle housing and painted it with Eastwood's Rust Encapsulator. Here are pics of the newly painted axle.

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After completing the rebuild on the D60, I installed the rear disk brake conversion located at this link: Disk Brake Conversion.

Next, on to the rebuild of the front D44HD. This was without a doubt the harder of the two axles to rebuild. The following parts were installed on this axle: ball joints, spindle bearings, axle ujoints, seals, wheel bearings, and Detroit Trutrac LSD.  I disassembled the entire axle and started with installing the new ball joints as seen below.

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Notice the old ball joints in the above pic...the two upper ball joints were not only flopping loose, but somewhat bent. Also showing is Rust Encapsulator painted on the steering knuckles.

After reinstalling the steering knuckles onto the axle housing, I painted the rest of the axle housing with Eastwood's Rust Encapsulator.

Next, came the installation of the Detroit TruTrac carrier and 4.09 ring & pinion. This install took me about 5 evenings to complete and was the most frustrating part of the axle rebuild project. It took many installs of the pinion, and carrier...shimming back and forth until I reached a good pattern on the ring gear and settled on a backlash of .010. Finally, the axle shafts, spindles, caliper brackets, hubs & rotors, locking hubs, and the new calipers and brake pads were reinstalled. Also, new tie rod ends and steering stabilizer were installed.

Here is a pic of the completed D44HD.

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Next came the day of the axle swap.

These pics are showing the install of the rear D60 axle complete with disk brake conversion.

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Next came the install of the front D44HD.

This pic is showing the rig just after the old D44 was removed.

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This pic is showing the new D44HD after manuvering into place.

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The next morning after the axle swap.

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With the axle swap being completed, to finish, the next upgrade was the stainless steel brake lines for a 4 inch lift sold by BJ's Offroad.

I'm very pleased with this axle rebuild and upgrade. The axles, rear Detroit Locker, and front Detroit TruTrac LSD have proven to be a very effective driveline on and off road. It's really good in MUD too!!!

 

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