This idea started in another thread, and may have already been done (although a search didn't turn up anything)

Here's what I'm thinkin': Wire in a switch that forces the Center Axle Disconnect to unlock while the transfer case is in low range. This would result in being able to use low range when backing a trailer uphill or when pulling stumps to save unnecessary shifting from 2wd to 4 low, as well as being able to disengage the front axle on a tight trail without having to shift all the way back into 2 high.

Mechanically speaking, the system would still lock the front driveshaft, so as long as you weren't unjudiciously spinning the rear wheels, no damage would occur to the front diff thanks to over-speeding a broken axle shaft. In fact, that's exactly how it would perform: As though you had a broken axle shaft because, well, essentially you would.

Electrically, all you'd need is a pair of wires, a DPDT ON-ON switch, a couple of connectors, and some time. (I drew up a rough sketch of the wiring, but I can't scan it in and post it until tomorrow at work) Basically, you'd clip the wires used to ground the vacuum solenoids that actuate the CAD, connect the center terminals on the switch to the GEM side of the cut, and connect the solenoid side of the connectors to one set of the terminals on the switch. Then, connect a small jumper between the unlock solenoid wire in position A to the lock side of position B. (I know, verbally that makes no sense.... I need to scan the sketch in) So, in switch position A, the system would function normally. In switch position B, and when in 4high or 4low, the GEM would think it's grounding the LOCK solenoid, when in fact, you'd be re-routing the signal to ground the UNLOCK solenoid.

I'm 99.99% sure it'lll work just fine. If you want the simple spot, you can clip the wires under the hood. If you want to get real fancy and have some time, you could clip the wires near the GEM inside the dash, where all the connections will be out of the elements.

I'm willing to give it a shot on anyone's truck that would like me to try it. I promise not to cut anything without being 100% sure it'll work, and if it doesn't work, promise to return it to the way it was.

(sketches to follow in the AM)

-Joe

 

I'm liking the idea so far! Looking forward to the sketch.

Mitch

 

Someone reminded me of a product that's out there that already does this.... sort of... www.4x4posi-lok.com They make a manual conversion kit for the center-axle disconnect, but it's a fair amount of work to install it.

-Joe

 

This happened to me yesterday. I shifted her into 4x4 but nothing happened and the light didnt come on, so I tried low range and the light didnt come on, yet I was in low range but 2wd still.