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NOTE: Since this article was written a number of years ago, Alloy USA has undergone some changes. In my humble opinion, it is not the company it use to be and the quality isn't there anymore. Ron Stobaugh, who was the driving force behind Alloy USA, has parted ways with them and started a new company, Ten Factory. Ten has hooked up with Motive Gear. Were I in the market for new shaft components, I would be contacting them for my needs. I've left this write-up on my site simply because it documents what is needed to do this work.
While the trail mud situation isn't nearly as bad here in Arizona as it is in
other parts of the country, we do get a bit every now and then. When it
comes, it comes pretty fast and is usually the result of summer storm induced
flash floods. Water crossings do occur (a group of my favorite trails is
located on the other side of a river) and so getting debris and such in the axle
tubes is a reality. I don't envy the folks that live in the really muddy
parts of the country as it simply must be nasty to clean up your ride after a
good trail run.
If you've looked at the factory D30 shafts, they come with a plastic disc (shown in the above photo by the arrow) that is slipped over the axle shaft. The plastic disc keeps the larger chunks of rock and wood out of the axle tube. They don't help when it comes to mud, water crossings, etc. as they do not make a tight seal against the entrance to the axle tube. As such, moisture, dust, mud, etc. can work its way into your axle tube. Later, when you remove and reinsert the axle shaft, it will normally drag through the debris and get into the diff seal. Not a good thing to have happen.
Alloy USA has a solution to the problem, billet aluminum CNC machined axle tube seals. They fit both D44 and D30 TJ axle tubes. Shipped two to a box, a pair of seals and a simple one page instruction sheet give you everything you need (except for a couple of wrenches) to install the seals in the ends of your axle tube.
I spoke with Ron, owner of Alloy USA, and found that the seals I was installing were actually the third generation design. In an attempt to build a better and more reliable product, the seal has been refined over time. From a few photos I've seen, the previous design had a couple of o-rings on the section of the seal that fit into the tube. This version now has a grooved sleeve that fits over the aluminum seal and engages the inner surface of the axle tube. From the looks of it, it should do a good job of ensuring nothing gets past the seal to axle tube interface.
The sealing surface between the seal and the axle shaft is a fairly flexible two lipped rubber seal that provides a sizable pocket that is filled with grease. As seen in the above photo, a standard grease fitting provides easy filling for the inner sealing area. The "seal of grease" also helps ensure the rotating axle shaft does not wear the sealing surface away as well as making a tight seal to keep out debris and moisture.
Many TJ mods require an assortment of tools and sometimes power equipment (welders, drills, grinders, etc.). The axle seal installation required just two tools.....a lug wrench to remove the lug nuts on my front wheels, the other a twelve point 13 millimeter socket to remove the brake calipers and the unit bearing (the Warn hub in my case) from the knuckle. It doesn't get much easier than that.
OK....on to the installation itself.
More Alloy USA Seals