1991Jeep_Man

My '91 XJ has that damned CAD system on the front Dana 30. With winter here in the Shenco, snow is an issue, and I'm tired of either having the front axle not engage, or it engage but then some unknown vacuum leak decides to sprout up and my 4x4 will kick in and out, which CANNOT be good for the NP231. Also, being as I am broke, I needed a cheap solution. I was very much intrigued by the write-up by 89Laredo for the Collar bypass. I know he put in there that this is a temporary fix, but is there any real downside to it? I drive I-81, so my XJ sees speed of 70-75mph. It's also a DD, alongside my '07 Focus.

I just need something I can count on for the winter. As soon as dollars start becoming more availible, I plan to buy the axles from Serious Offroad that eliminates this ignorant design. What do ya'll think?

Lowrange2

I think that for about 75 bucks you can go to a PAP and grab a non disco axle out of something a tad bit newer (93ish) and slap it in there in one afternoon.

Problem solved for 75 bucks.

jbsjunk

Do the bypass. It's free and easy.

cruiser54

Here's what you wanna do. Takes a half hour at the most:

https://www.cherokeeforum.com/f51/fr...ss-91-a-38629/

1991Jeep_Man

That's what I wanna do. My main concern was is there any downside to doing it? Some people have mentioned the 92+ XJ's with the solid axle piece have balanced front drive shafts because they are constantly spinning. But I figured even with the CAD, my front DS is always spinning because the driver's side is always engaged ?

TheJerm

The whole point of the CAD system is so the diff and driveshaft doesnt spin, "to increase mileage" but it really doesnt.

But my solution when I had a CAD axle in my 95 (free axle) was to use a hand vacuum pump to index the collar over and cap all the ports with rubber nipples. Or you can move it by hand with it off and then cap the vacuum motor. I ran it like that for quite awhile and never had any issues. I did an experiment driving 600 miles with it locked and the return unlocked, only difference was unlocked was alittle smother cause there was not vibe from the front DS. That was a balanced DS too and it took a minute with a hand pump to lock/unlock it. I only ever unlocked it that one time.