My 4x4 isnt working very well

I get no light when i shift into any of the gear ranges, how ever the xfer case is working because the front drive shaft is moving, you can tell when the rear end is put into 4L but the front wheels never turn, i tryed to check the vacuum but i couldnt trace where the lines were going.

I cant figure out where the vac lines begin, where do they get their vacuum from, and what in the hell is the thing under the battery is it some sort of other vac motor/storage sphere? Is there a way to test that light indicator sensor down on the vac shift motor?

1997 2500 HD

 

Sounds like low vacuum could be a possibility. Look along your firewall, right in the area where the coolant lines meet the heater core. You should see a small black, hard plastic line that goes thru the firewall. Now facing the front of the truck,...somewhere between where that line enters the firewall,.....and your brake booster (vacuum or hydro) , you will see a few taps off the main vacuum line. You also have 1 or 2 check valves.

The valves and the line inspection is the place to start. Then you can diagnose from there. The ball under the battery is part of the cruise control. That's the servo that physically increases or decreases your throttle.

If your cruise works very well, then you may have to go down below. There is a vacuum switch on the top of the tranfer case. You would want to see if any off the fittings have popped off somewhere.


Good luck with your ride.

 

the vacuum lines around the CAD and also where they cross over under the transmission are the most likely places to get messed up. with the truck in 4wd, one of the lines at the cad should have vacuum. the light is just a switch, activated by the cad pushing on it. its prone to get full of mud/dirt and need cleaning. troubleshoot the cad first, once its working look at the light.

here's one link.. https://dodgeforum.com/m_652880/tm.htm
another...http://www.4x4wire.com/dodge/tech/solid_axle_cad/

i remember another good one, but can't find it, will keep looking...

 

Been through this twice, once on the '97 2500 work truck and my personal '01 1500. Both times checked every line imaginable, check valves, everything and no fix. Both times turned out to be that the vacuum pod on the front axle was leaking air and could not create enough vacuum in order to move the collar to engage the front wheels. Change out the pod (way overpriced) and it works great. I was also told that any little burr on the driveshafts will create enough friction that enough vacuum can not be created in order tomove the collar over. I'd pull the assembly off and blow through on of the ports on the pod and see if you can feel/hear air coming out the other side, it's simple and easy to do and can save the frustration of chasin lines, and if it's fine, not that much time was wasted

 

theres also the $119 dollar posi lock option that u manually engage u front axle with a pull cable. i love it since u can also have 2L . ( although i made mine myself for $20 lol)

 

more reading for you...
http://www.dieseltruckresource.com/d...;highlight=cad
http://www.dieseltruckresource.com/d...;highlight=cad
http://www.dieseltruckresource.com/d...hlight=2wd+low
http://www.dieseltruckresource.com/d...;highlight=cad
http://www.dieseltruckresource.com/d...;highlight=cad

do these links work if you don't have an account there ?