4wd problem

[Cummins Man12]

I have a 1996 2500 single wheel auto cummins and in this past snow i was usin the 4wd and i would put it in and it wouldnt go in till i fiddled with it a little or put it in park theb drive and a few other things is somethin goin bad or is that just normal it takes a little bit for it to go in?

[articfarmram]

if it´s real cold the gear oil in the front axle gets so "thick" wich makes it hard to engage 4wd but my guess is a vacume leak. 4wd is partially controlled with vacume and the front axle angege system is known to be problemmatic.. It´s the thing thats is on the passenger site of the front axle in the back.. there are 2 vacume lines and an electric plug.. disconect all three remove the 4 bolts and clean it up. thats where an air compressor is handy.. Next step check out all the lines envolved in the vacume system the main hose from the vac pump to the brace cylinder is known to soften up. my advice is remove it and go to an hydrolic store and ask for another that is vac proof.. in this hose ther is a T that goes conects to the vac lines on the fire wall from there to the right it leads to the crusecontrole unit. To the left it goes to the plowermotor and the transfer case. the line to the transcase runs frum the fire wall down and behind the 6th valvecover. in the back there it goes from a hard plastic line to a idiodic rubber knee and goes from there to the top of the transcase. sorry man hard to explain from memory just check it all...

[moparguy55]

Sounds like a vacuum leak. With your heater blower motor up high if you change the selector for where the air blows out in the dash does it work ? My old truck had a leak and when you tried engaging 4wd it took `5 seconds or so. When i changed the dial position for the vents it didn't move them either the air kept blowing out the same holes. The vent actuators are all vacuum controlled too. I had leak at some of the vacuum T's. I had enough vac to engage the front axle after, but the dash vents were hit or miss. i think it was the switch on the t case.

[articfarmram]

I recomend rebuilding the vac system. its not expensive and you can pressure test the whole thing befor final aslembly Nice way to spend a saturday afternoone with a cold beer

[Cummins Man12]

yeah cause the only vents that word are the defrost vents non of the ones on the dash

[joes_yj]

put a posilock system on it, trust me its worth it

[moparguy55]

Originally Posted by Cummins Man12

yeah cause the only vents that word are the defrost vents non of the ones on the dash

Mine was the same only defrost. If you have to start forking out money if its the switch ect I'd go the route joes mentioned with the manual cable to engage the front axle.

[Cummins Man12]

Ok cause when we messed with the vacum my abs lite would turn on but they still work

[blackimpala]

Hope this helps.

http://www.dodgeram.org/tech/repair/..._engagment.htm

Floyd

[Cummins Man12]

Thank ya ill check that site out