Posted by Matt Wilson on Wednesday, July 14, 2004 at 2:50PM :
In Reply to: dodge 9 5/8 case install lock right posted by Joel Snider on Wednesday, July 14, 2004 at 2:03PM :
The Power Wagon differential case is like no other unit I've ever seen. It consists of the main body (the cylindrical portion that houses the spider gears and shafts), and a "cap" on one end that closes up the differential case.
You can tell where the cap mates up with the main body by finding the separation line between the cap and the main body. The cap screws into the end of the main body (sorry, I don't have a picture with me to post). You have to remove the carrier bearing from the cap before you can get the cap off. Not only does the cap screw into main body, but it is also held in place by three pins that go through both the cap and main body, and it also has somewhat of a press fit in the body. You have to drill out the three pins, and then you have to use a special wrench that fits into the three large openings on the end of the cap (not talking about the holes that remain after drilling out the pins, but rather the large openings that surround the carrier bearing journal part of the cap). I had to actually build a wrench to do this job - I'm never throwing that thing away. The wrench has a cylindrical portion (made of pipe) just large enough to fit around the carrier bearing journal, and three long tangs or fingers (made from bar stock) that fit into the three large holes that I was talking about above. The wrench also has a long moment arm (a couple of feet or more) for good leverage.
You also need to create a mounting fixture that bolts to the ring gear bolt holes, or find some other way to strongly secure the main body. With the pins removed and the main body mounted in your fixture, you put the above-mentioned wrench into the end of the cap and start heating the main body near the cap with a torch. Do not apply the torch directly to the cap, or else it will expand. The reason you must heat the body is because the cap is not only screwed into the main body, but it also has a press fit (as mentioned above)...yeah, they really didn't want this thing to come apart.
All the while, you need to be applying a good amount of torque to the wrench, preferably "popping" it with some sort of hammer. (Take care not to damage the surface where the carrier bearing presses onto the cap, especially the radius at the base of journal.) If you are successful in heating up the main body of the diff case without heating up the cap too much, then one of your "pops" will loosen the cap, and you can then unscrew it easily from there.
Re-installing it is the reverse. I heated my differential case main body in the oven at about 300 degrees, and I stuck the cap in the freezer for an hour or more. They went together easily. You then have to put three pins back in (available in rebuild kits), and the way it went for me, I had to drill three new holes to accomodate the pins, since the old holes no longer lined up with each other. It was difficult to keep all of the shavings from getting into the spider gears and shafts, but I did my best to flush them out when I was done.
This is quite a bit of work, and building the special tools is a big part of it, but if you don't have the means to make the tools, then maybe you can contact a friend who has a machine shop or at least a welder, or you might even draw up some sketches and take them to a shop to have them built.
So far, I haven't had any trouble with mine (I did the front and rear, but had some else set them up for proper mesh).
Good luck!
Matt
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