HI all. I have a 96 dodge ram 3500 with 5.9 diesel. Just went to use the 4 wheel drive and it would not engage. The 4x4 light did not go on, I was having trouble with the light flickering last winter even when it was in 2 wheel drive.I think that is just the 4x4 indicator switch on the axle.Or does that switch also engage front wheels? 4x4 shifter seem to be working fine? Is front wheel drive engaged by vacuum, or electrical ? Where do i begin. Please help. Thank You Nitro 1

 

The front uses vacuum, do you have any trouble with the cruise control or the blend doors for the HVAC system. If not then I would assume your issue is that there is not vacuum at the transfer case, or one of the lines from the transfer case to the front axle is not connect well. To check the lines at the transfer case you can engaged 4x4 and climb under the truck with it running and parking brake set. See if you feel vacuum from the red or black tubes that connect to the hard line running to the front axle. The red and black soft lines come down right on the cross member. If you have vacuum there just work your way forward. If you have vacuum all the way to the shift unit on the axle, remove it from the axle and make sure it and the collar both move freely. HTH

 

I am not sure if your year of truck has the vacuum actuated CAD (center axle disconnect) or not. Mine is a 2000 and it does. When I got my truck a year ago the CAD wouldn't work. I confirmed that it was the CAD and not just the actuator light by disconecting the electrical boot and jumpering the wires. Turned on truck and 4x4 light came on so I knew electrical indicator was working properly. After listening to a lot of advice from people on this board I agreed that the vacuum actuated CAD was prone to failure for a dozen reasons. I bought a Posi-Lok CAD actuator. It replaces the vacuum actuated system with a cable. It cost $200 and took me a couple of hours to install. I now know FOR CERTAIN when my front axle is locked. You can feel it engage through the cable. You will get a lot of info about how to test, diagnose and fix your vacuum actuated CAD but if you exhaust all of that and you are at your wits end, Posi-Lok is cheap, easy and it will never let you down.

 

i agree check your vacum lines red and black..i had same thing with flickering but didnt stop it from going into 4x4 then nothing happed... the vacum lines and work there way off at tranny.thats all it took

 

Thank you. Sure enough I checked the red and black vacuum lines, and one of them is broken. You guys ROCK!

 

Hey folks thanks again for the help on the front wheel drive on my 96 ram. I finally got around to replacing the steel vacuum lines. that was one of the problems. I removed the vacuum actuator on the axle.the vacuum bellow was all rotted with holes. any one know where i can get one. ill check the dealer. thanks again Nitro 1

 

Rock Auto has them in the Dorman brand for 73 bucks.............

 

I'm glad that I have just the transfer case shift lever for my 4 Wheel drive! 1994 Dodge Ram 4X4 cummins 5.9!

 

Uhhh, I don't think so Tim......( sorry, best tool time shot I could think of. )

Is yours converted to the part time kit or do you have a posilock 4X4?

If not, you have the same potential problem.

 

Mine is a Posilock 4X4. Front end is in gear all the time and engaging 4 wheel drive transfer case puts it into 4 wheel drive. No vacuum lines or hoses. I have been thinking on making mine a part time front end, but not the vacuum operated one. I would go with a manual locking hub conversion from either a Dodge or Ford with TTB and just eliminate the front wheel unit bearings.

 

That's where I am heading, Brownie had a Posilock 4X4, I liked it, but not enough to keep it and switch it over when I decided to keep Greenie.

I am going with the manual hub version as soon as I can find a Furd to rob the parts from.