Over the last couple of days there has been a lot of mixed roads conditions, going from icy, to packed snow and also dry pavement. I looked up the 4x4 system for my 1998 Dodge Ram 1500 5.9 online and concluded I was able to shift from 2hi to 4hi and from 4hi to 2hi safely while in motion up to 50mph. After learning this, I began experimenting at low speeds (under 25mph) but quickly realized the it would shift from 2hi to 4hi no problem, but going from 4hi to 2hi, there is some occasional clunking while the 4x4 light stays on and I begin to smell what I believe is burning fluid coming through the heater system. Sometimes this happens and sometimes it does not. Then I thought about stopping, shifting into N on the steering column and then trying to shift into either 2hi or 4hi, but didn't notice any difference one way or another. Can someone help me diagnose this?

 

Lazy CAD disengagement, and probably some questionable u-joints in the front driveline. Check all the vacuum lines to the cad, they like to get dry, and brittle, and then break, and the metal lines tend to rust out. Need good vacuum signal for the cad work properly.

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