Well tonight was the first time I noticed the 4x4 was not working on my 98. Our first good bit of snow and ice in SC. 25 degrees and 6 inches of snow in 3 hours. Thats alot for us. I put the truck in 4hi & 4low, jacked up the front wheel, the wheel turns. Tried to turn the front driveshaft w/ both front wheels off the ground, driveshaft will not turn. Took vacuum lines loose from vacuum pump on front diff and there was no vacuum at all. Took vacuum lines loose from transfer case and still no vacuum. What could my problem be? Plus my 4x4 light on dash does not come on, but I have replaced the indcator on the front diff. Is there a vacuum switch on the transfer case that the lines go to?

 

Still no vacuum on the lines or at the transfer case? You wouldn't have it on the lines at that point. But you should have vacuum at the transfer case. I've never heard of a loss of vacuum at the transfer case.

 

If there's no vacuum at the axle, you'll get no 4wd light ... it's a simple switch that is tripped when the fork slides the sleeve over the half axles. A couple of pictures are worth 20 posts so: http://dodgeram.org/tech/repair/4X4/4x4_engagment.htm

 

Where is the vacuum switch on the transfer case? I see the lines at the skid plate but I can't tell where they go (Just taking a glance).

 

Driver side just above the where the shift linkage connects to the shift arm on the TC. There is also a hose that goes from the pass. side of the intake manifold and goes down the back of the engine the the switch.

 

Good Deal, thanks man. I'll get out there in a few and check the switch.[IMG]file:///C:/Users/LADENB%7E1/AppData/Local/Temp/moz-screenshot-1.jpg[/IMG][IMG]file:///C:/Users/LADENB%7E1/AppData/Local/Temp/moz-screenshot-2.jpg[/IMG]

 

I just changed the vacuum switch at the transfer case and there is still no vacuum anywhere. There is a slight bit of vacuum at the switch on the transfer case but thats it. I'm lost. I followed the lines and found no leaks or broken lines.

 

Did you check the hose from the eng. bay down to the TC?

 

I couldn't find the vacuum hose in the engine bay at first glance, I gonna go double check it in a second.

 

OK, I'm getting vacuum at the switch on the transfer case. I'm also getting vacuum at the metal vacuum lines at the transmission mount but NO vacuum at the vacuum motor on the axle. I used my air compressor and sprayed both the black and red vacuum lines on the front axle. Now, what else could I check?