I am getting my truck ready for the coming MI winter and have replaced my old worn battery and got some new tires. Tested out the 4wd last night and all seems well. I remember last year in the middle of winter it would always engage but would sometimes take 20 sec-1 min. to disengage. When it did it would make a thud I could feel. I figured this is something to do with the actuator. Any input?

 

in order for it to disengage it needs to be able to roll on a solid ground for like 5 ft or so, but if your still on a snowy road or something like this, then it can take longer. also the thud can be from it finally disengaging but maybe you were on the move and going to fast? remember it can only shift on the fly up to like 50mph from high and low you must stop, it says u can do it going like 3-5mph but id just stop and do it.

 

I don't know about the thud, but when I had issues with the 4wd system it was a vacuum supply issue. Both lines apply constant vacuum iirc, one to hold it in 4wd and one to pull it out and keep it out of 4wd. You might not be getting enough vacuum to pull it out very quickly/correctly. I just did a redneck fix and ran a vacuum source to the cab, then a little distribution block thing, and then two vacuum lines to the front axle, one for 2nd, one for 4wd. I would just pull the lever to engage the transfer case, then switch lines to engage the front axle. It wasn't nearly as convenient, but more direct and reliable

 

I was getting a thud going from 4h to 2h at 20mph-40mph, foot off the gas.

 

Personally, I would always shift at slow speeds. I know it says shift on the fly up to 50mph, but it just seems like it would be more stress on parts.

 

And I don't think it's anything in CAD itself making a thud, I would guess it's in the transfer case or driveline somewhere, maybe a bad front u joint? I could be wrong though

 

Hopefully it was a front u-joint. I just replaced both sides up front.

 

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