Free D30 CAD Bypass (-91)
 

I got tired of not having 4wd today and decided to lock my axle disconnect over. This locks the 2 pc passenger side axle together essentially making it like the 91+ models with the 1pc axle. This way you will not have to wonder if your front axle is locked in just put it in 4wd and go!

It is very easy to do and I would say it takes about an hour.
The only tools required are a 11mm socket, jack, some gasket maker, gear oil, and something to get the c-clips on/off.
Jack up the passengers side and locate your CAD assembly. It is the weird looking piece on the passenger side axle tube with three vacuum lines running to it. Yours (hopefully) wont be as dirty.

http://i981.photobucket.com/albums/a...5/100_1434.jpg
Next step is to put a catch can underneath it, get your 11mm wrench/ratchet/whatever and loosen the bottom two bolts a few turns. Allow most/all of the gear oil to run out (a couple ounces). You can now remove all four bolts.

Once you have the disconnect assembly off, clean it up and get something around to remove the C-clip. I honestly think the removal of the C-clip was the hardest part. Be careful as it WILL go flying and be hard to find.
http://i712.photobucket.com/albums/w...lipremoval.jpg

Move the shift fork over past where the clip usually rides and then reinstall the clip. Your shift fork is now in the "locked" position.
http://i712.photobucket.com/albums/w...pinstalled.jpg

For the next step, go back out to your jeep. You will need to move the locking collar over into the "locked" position. You may have to rotate the tire to get the splines to line up. You will know you have it if the driveshaft spins when you rotate the passengers side tire.
http://i712.photobucket.com/albums/w...889/locked.jpg

Clean the mating surfaces of the shift motor and axle disconnect area. Install a thin bead of RTV or gasket maker of your choice. (I got away without using it, but its highly recommended)

Install the shift motor being sure the fork lines up with the collar. Tighten the 4 bolts in a criss-cross or hex pattern a little at a time being sure not to tighten them too much and strip the holes out.

You are done! Check your gear oil before your first ride, you may need to add a couple ounces since some was lost when the CAD assembly was taken off.

So far I have had no bad vibes or extra noise from the front driveshaft rotating. Keep in mind this is supposed to be a "temporary" fix, but I have heard of people running this way for years. My 4wd now works like it should and I am very happy overall with it.

Note: pictures where taken from Dodger889's writeup on Jeepforum.com