so i just picked up this 94 cummins reg cab long bed few mods got a decent deal. wont goin into 4wd.
the front axle will turn with 4x4 engaged but wheels wont turn, so basically hubs just arent locking.i hear its just a vacuum switch, thye get gunked up and need to be cleaned and back to normal? 3 diesel guys with 12 and 24vs told me this and just want some more info. what do i "clean" what needs to be done ect.

 

Check your CAD "central axle disconnect" it's the collar lookin thing on the frot axle. That houses a mechinisem that slides back and forth to engauge and disengauge the axle. There will be some rubber tubing around that area make sure they all have a home and aren't cracked and leaking. Time to crawl under the truck and trouble shoot, good luck

 

these are common. there is a vacuum canister on the front axle, those eventually leak and so the four wheel drive wont work. dodge decided to go with vacuum operated for some reason. so replace that it will fix it.

 

or install a 4x4 Posi Lock cable actuator:

4x4 Posi-Lok - 4WD Engagement Systems

 

I wish id have known about theses before I relpaces every vaccum line on my rig

 

posi lock is the way i went and i really like being able to put it in 4 lo and be in two wheel drive it takes the shake out of my ceramic clutch when tryn to ease in under trailers

 

what kit is the one i need? how many people have this?

 

go big or go home put lockouts on it cheap bearings totally servicable able to run a front locker without air or electrical lines

 

try checking your u-joints on the hubs. when they are wore out they put the axles at an angle. mine wouldnt go in and i replaced the u-joints and check the sleeve that slides over the axle behind the vacuum acuator to make sure the splines on the axle are in good shape. i had to file down the edges of the splines to smooth them out and then mine started working great. havent had a problem since.

 

Thats right......Me and this guy did it.......Well worth the money......