So the last time I put my truck in 4 low it popped twice real loud and since then if I put it in 4 wheel drive at all front wheels do not pull. For about a month after that when I was drivin down the road it would start making like a grinding sound from the front end. Then one day the grinding just stopped. But still no front end pull. Haven't had a chance yet to pull the inspection plate and check it but just curious to sread if anyone else has had this issue or if you might have an opinion on what it could be. It's a 97 ram 1500 SLT 5.9 V8 automatic 3.55 gear manual 4x4 (not push button) auto hubs

 

Does the 4x4 lite in the dash come on?

 

It will come on if you drive it a quarter mile or a little less. Before this happened it would come on but had to drive it 1/8th to a quarter mile before it would lock in and start pulling and the light come on. Now when I try and put it in 4 low it will lock in low gear but the front wheels still won't pull.

 

Have a look here. Likely a vacuum problem.

 

Sorry man I get a blank page when I click that.

 

That's odd..... Works fine for me.

Could always grab the FSM from here, same info is in there.