Join Date: Oct 2001
Location: Sitting at my desk
I believe the tj axles should swap straight across. I've never had to change an axle yet, but since folks do it on the trails, it shouldn't be too hard. You should be able to find a couple dozen people on the board that can talk you through it.
What I did is not quite main stream, yet. 1st, a little background on the front axle setup, so that you will forever be knowledgeable in your jeep front axle.
The drivers side axle is 1 piece that connects into the front differential. This axle always turns, which turns the diff, which always turns the front drive-line. But since the transfer case is not supplying power to the drive-line, it freewheels until you lock in 4wd.
The passengers axle is a 2 piece unit. The inner axle is connected to the front diff. and always turns. The outer axle is connected to the inner axle, but it is not a solid connection. The outer axle is also connected to the passenger side wheel, obviously. Since the inner and outer are not directly connected, the outer freewheels inside the inner and they can spin at different rates. I have no idea why jeep did this. The new tjs are 1 piece on each side and they did away with the vacuum motor. That makes perfect sense.
Inside the vacuum housing is a metal fork and a metal collar. The collar is splined to match the axles. When vacuum is applied to the inner side, a rod shifts the fork which slides the collar across the gap, and locks the 2 axles together. Now you basicaly have a solid axle connected to the diff. The transfer case applies power to the front drive-line, and voila! 4wd. That is after a short wait while the axles sync up.
The vacuum motors go down pretty often for a variety of reasons. The posilok replaces the vacuum motor with a cable that slides the fork and collar manually. Much more reliable. My method works for open diffs. I have no idea how it will handle if you have a hard locker up front. If you do have a hard locker, I'd recommend the cable. Air locker or the ox should work fine with mine.
For my method do the following. Jack up the front pass. wheel and put on a jackstand. Chock the rear wheels 1st. Crawl under the jeep and take a look at the pass. axle housing. The vacuum assembly is held on with 4 bolts. Pull the bolts and the housing should come off. You might have to give it a couple taps to loosen the gasket. Some gear oil will come out. Gear oil smells worse than anything I can think of, deal with it.
Once the housing is off you'll be able to see the fork/collar assembly and how it works with the axles. Rotate the pass. wheel while putting a little pressure on the collar. The axles should sync up and the collar will slide across the gap and lock the axles together. You now (for all intents and purposes) have a 1 piece axle, just like the Tj's. Now all you have to do is keep it from sliding back. this is the highly technical part. And the part that is the most expensive.
Slide the fork all the way to the left inside the housing. On the right hand side of the vacuum motor (big round thing)locate the center of the motor and drill a small hole through the outer piece only. Then take a sheet metal screw about 1 1/2" in length (that's the expensive part) and run it in until you feel it connect with the outside of the rod the fork rides on.
This will keep the fork locked to the left and keep the collar from unlocking the axles. Put some gasket maker around the screw to seal the hole. The entire assembly is sealed internally around the rod, but safe is better than sorry.
Then replace the housing, making sure the fork slides back into the groove on the collar and bolt in place. I re-used my gasket, but you might need a new one. You now have a 1 piece axle on each side of the diff. Once you engage your transfer case you'll have instant power to the front end without having to wait for the axles to sync.
I've been running like this for a while, and the only downside I've found is that the 4wd light is always on in the cab. there's been no affect on function or handling in either 2wd or 4wd.
I considered placing something over the rod,but I was worried it would work it's way off and into the gearing.