I had an option of using a 94 straight or an 89 CAD D30 for my build. From the standpoint of strength I could see no reason to favour the straight axle over the CAD with stock axles being the limiting factor. Well at least not for my purposes. Since I wanted to use a PowerTrax locker which I already had, the safety issue won out over the complexities involved with a CAD system.

So, now for the how to use the CAD axle in a 94 build?

I looked at the cable system from Posi-Lok and was ready to jump but when I read further and realized it was a combination pushing and pulling while making the vehicle roll to get it to engage/disengage, it just didn’t work for me considering I’m building with a manual trans.

Since my 94 lacked all the vacuum lines and controls I knew I was going to need to either go with the Posi-Lok or come up with something from scratch. So I concentrated on a custom setup, ideally one that could be set with the flick of a switch on the dashboard that would work the actuator transparently like the factory install and come in at or below the Posi_Lok system of $159.95 +.

What I came up with was a circuit using a 12 volt solenoid controlled, 2 position, 3 way valve. Since in order to move the actuator you have to first release the vacuum on one side before applying vacuum to the side you wish to move I needed 2 of these. However, after building my prototype it occurred to me that one proper 2 position, 4 way valve should be able to accomplish this and lower cost.

Parts:
(2) 3CDY8AY 12VDC solenoid valves $108.87 shipped
(1) Cole Hearsy Vacuum switch normally off, 7inHg set point $14.79 shipped
(1) single pole double throw switch (Advanced) $8.95
Brass fittings (Home depot) $11.34

Total: $143.95

If I throw in a couple more bucks for wire, hose and the idiot light for the dash I’m right there with Posi-Lok but a single solenoid would bring it down $20-$30.

See link below for quick vid of layout and demo of the setup

http://www.youtube.com/watch?v=f08AI...ature=youtu.be

 

If you buy this you just install a one piece axle shaft on the passenger side. Making it exactly like the 94 axle

http://www.rustysoffroad.com/rustys-...-seal-kit.html

 

The idea was to keep the CAD since I'm running an auto locker.

 

Do you have a 231 or a 242? Because I can assure you that if you have a 231 then it was pointless. Can you explain why you want the cad?

 

Ok, two reasons

The engineers that design these vehicles are pretty smart and more importantly are loathe to waste money. The CAD system isn't a cheap ad on and the engineers felt it was worth the money in terms of tire wear and gas mileage with either transfer case.

But more importantly

The engineers at both Richmond Gear and Standard gear that i talked to both strongly recommended not installing an auto locker in the front without some kind of disconnect (I.e. either CAD or Unlocking hubs)

I won't argue that you can get a stronger build with aftermarket single piece axles but for my purposes this works.

 

Honestly, I'd sell the powertrax and get a selectable locker to run in the non disconnect axle. Doesn't make sense to use the older disconnect axle when it just sounds like you would like a selectable locker.

Spare shafts are going to be way easier to find too, and if you break one on the trail, chances are a buddy has an axle shaft that would work for you.

 

My question then is why was the system deleted after 91'? Because they realized it wasn't worth the money.
And please don't tell me that you have a 231 and drive on the street in 4wd because you're gonna destroy that Tcase. The vac disconnect is pointless on road as the 231 has no slip in the case like the 242 does so even though one side of the axle isn't connected, the other side is and it's going to put hell on the Tcase if you're in 4wd. It's smarter and stronger to go one piece axle shaft. And either auto locker or selectable. Ask the other thousand and thousand of xj guys who have a auto locker up front and a non disconnect axle. There are no issues. Now if you have a 242, that might be different. But as stated above, a selectable would do best

 

Ok, Ok.. I see your points.

It comes down to money and doing the best with what I had. BTW they continued the CAD on YJ's until 95.

 

Cheapest option is just get a one piece shaft from the junk yard and put it in the vac disconnect housing if you already have it.