Building a Reverse Rotation Front Dana 44

by Mike Knorr
Visit Mike's website: www.bc4x4.com/thbsjeep

August 1, 2000

On the surface, building a reverse rotation (RR) Dana 44 for the front of a CJ-7 sounds like a straightforward project. But the problem is that all the factory reverse rotation Dana 44s have the differential on the wrong side (ie: driver's side) of the vehicle. A completely custom axle is the only route. Of course if you have the money, you can skip reading this article and call any one of the custom axle builders and have one made for minimal headache. Since I'm a die hard do-it-yourselfer and very short on cash I decided to tackle this myself. It didn’t hurt that I knew someone who had successfully completed this project years ago. I didn’t let his words of discouragement stop me and I to went down the road to re-tubing a reverse rotation Dana 44 to get a passenger side differential.

Let's start off with the parts that were used or destroyed to make this project. A Dana 44 RR was salvaged from a 1979 Ford Bronco and by the time I got it the tubes had already been cut off just outside the differential. A Chevy 10-bolt front-end was going to be thrown out by a friend so this became the donor for the axle tubes. The Detroit Soft Locker came out of my scrapped Dana 44 rear end. A new set of 5.13 RR gears were procured over the Internet. The knuckles were salvaged from my existing front-end. New Warn axle shafts were obtained from Custom Welding in Williston, ND. New spring perches were procured from Lou Feger's Racing in Delano, MN.

"Some assembly required"

To start the project I needed to remove the remaining stub of axle tubing out of the differential. I needed several cobalt drill bits to accomplish this. I started by drilling a small hole in the center of all the plug welds. After that, I kept increasing the size of the hole until all the plug weld had been drilled out. An air grinder was used to remove the weld that was offset to one side. For those of you playing along at home, a Dremel tool could also handle this job. The next step was to get the tubes free from the housing. Here I used heat and shrinkage to my advantage. I laid a bead of weld around the entire inner diameter near the outside edge of the housing and then again near the inner edge of the axle tube. Then I let it cool. The welds shrank the axle tube enough so that it could be driven out easily with a punch and hammer. Once the tubes were out, I ran a Dremel tool around all the plug weld holes and cleaned up any rough edges. Next I ran a cylinder hone in the bores to clean them up. Do this very lightly as you don’t want to lose the press fit of the axle tubes. I then sandblasted the housing and moved onto getting the axle tubes out of the 10-bolt.

This next step proved tricky because I had to torch away the plug welds but not cut into the axle tubing. My torch work isn’t the greatest so my friend Larry Keck stepped in and helped me with this. He was able to start cutting the housing at the edge were the tube presses into the housing and then just keep cutting down into the housing along the edge of the axle tube until the plug welds were cut free. We then used a sledge hammer to drive them free from the housing. Once the tubes were freed, any nicks were welded up and ground smooth; all the slag was ground off; and the tubes were given a light polishing on the end that gets pressed into the housing. Since the axle would have to be narrowed, the inner knuckles were cut off at this time. With the axle housing parts disassembled, we had completed the most difficult part of the project. The next phase of the project took much less time and was much easier.

The next step was to press the tubes into the housing. First MARK THE HOUSING FOR SHORT SIDE AND LONG SIDE TUBES. I had marked the housing and still almost pressed the tubes into the wrong sides. You get used to looking at a regular rotation axle and it is too easy to make this mistake and ruin your new housing. I used heat and cold to do the work of a press for me. It was winter in Minnesota so I just set the axle tubes out in the bitter cold so that the metal would shrink. Then I used a rosette head on the torch to lightly preheat the housing. Once the housing was warmed the axle tubes were retrieved from outdoors and the tubes were dropped in. I consider this pure luck as we had planned to use this just to help with the pressing. Since we did all this work under a fifty ton electric/hydraulic press, we were planning on using it but it ended up being unnecessary. The tubes dropped right in. While the housing was still warm the axle was checked to see that everything was level and square. Then the housing was heated some more and the plug welds welded shut with high nickel rod. The axle was allowed to cool slowly.

The tubes have been pressed in but not yet welded.

Checking the alignment.

Plug welds completed.

The next step was to cut the axle tubes to length. Several measurements were taken and a width was decided upon and marked on the new axle. All measurements were double- and triple-checked and then the axle was cut with a chop saw. Next, the spring pads were added. The passenger side spring pad required grinding on the differential to remove some webbing that was cast into the housing from the factory. Once the housing was re-shaped, the spring pad had the curve on the lower side opened up to match the diameter of the housing. Several test fits of the u-bolts and a little cleaning up with a grinder got everything set. Then the angles for the driveline were checked and the spring pad was set and tack welded in place. The other side was then positioned and tacked in place. Now it was time for a test-fit. The axle was moved under the Jeep and bolted to the leaf springs. With the axle resting on jack stands, the Jeep's weight was lowered onto the axle. All angles and measurements were re-checked. Once we were confident that everything was where it should be, the axle was removed from the Jeep and the spring pads were fully welded.

Trimming a little off the passenger-side. Notice the use of the angle finder to make sure the cut is straight.

Setting the spring pads. Notice the reshaping of the housing on the passenger side.

The knuckle and spring pad with the finished welds.

Once the spring pads were set it was time to place the inner knuckles on and set the caster and camber. The inner knuckles were pounded on with a sledgehammer. When they were about half-way on, they were checked to make sure the caster and camber were correct and matched side-to-side. They were then pounded the rest of the way on and again re-checked. Once everything was correct the inner knuckles were welded in place. That was the end of the custom work on the axle housing. Now it was just a matter of re-assembling it as you would any other axle.

It sounds like a lot of work. Was it worth it? Well a reverse rotation axle is stronger than a convention rotation front axle. The extra clearance the higher pinion offers is also a nice benefit. I haven't had a chance to give it a lot of real-world testing yet but I would say it was worth the time and effort. I was fortunate that it was a fairly low cost project (not counting my time or those Warn axle-shafts). If you are one of those die-hard 'wheelers who has to have everything then by all means do it. I would like to thank Mark Pollman, Craig Wiggert, Larry Keck, and Myron Hansen for all their help in this project.

The finished housing!