I just bought a 2000 Ram (5.9L,auto, 4wd, quadcab) with 120k mi. and it wont go into 4 wheel high. I can shift it forward into 4 lo, but the shifter just physically wont go back into 4 wheel high. The 4WD light on the dash comes on in 4 lo like it should. Do you think this is a transfer case issue or a vaccum line issue? I'm new to the four wheel drives so any help would be greatly appreciated

 

are you in drive when you go from 2hi to 4 hi?

 

No, I've put it in nuetral and park and the shifter still wont pull back into 4 high from 2 high

 

do it in drive. get rolling, let off the gas a little and yank it into 4hi. if you do it when you're stopped then it'll take a couple seconds to engage. it is sounding like a transfer case issue since you say that it won't pull back but try that first.

you only need to be in neutral when you go from 2hi to 4lo (rolling a couple miles per hour without pausing in neutral on the 4x4 shifter). and don't shift the 4x4 while in park.
if you get gear clash going into 4lo then you can put the truck in neutral, cut it off, shift into 4lo, then start it back up and hold on. when mine is in 4lo, i have to stand on the brake pedal to keep it from walking away from me.

 

dodge preferred method is to shift in to 4 hi at 5 to 10 mph same to shift out. this was told to me by a certified dodge house mechanic

 

and practiced by me many times. i've been halfway up a steep hill before, started to spin, let my foot off the gas and yanked it into 4hi then went on my way up the hill.

 

Well crap. I just tried it while goin about 5 and the shifter still wont pull back into 4 high. I think I might get under there in the morning and hit the linkage a few times to see if it'll go back

 

i can't predict what's wrong, but i can tell you that the 4wd indicator light on the dash is triggered by the movement of the front axle cad, which is triggered by a vacuum change, which is triggered by a vac switch on the top of the t-case, which is triggered by movement of the shafts inside the t-case, which is triggered by the shifter handle that you're pulling/pushing on.

sounds like 4lo and 2hi are working fine.

the front axle CAD lockup is a separate issue to the more important t-case shift.
if your lever is not moving, then the problem is all t-case and/or shifter, and has nothing to do with CAD.

a very common problem is a broken snap ring on the output shaft. do some searching on that. it typically causes grinding noises as the shafts slide to far out of place, but that might? be your problem.

 

doing 45mph today and started sliding and i whipped it into 4hi no prob at that speed.