I have a 94 3500 5 speed 4X4 that is making a popping noise when in 4wheel drive. I replaced the clutch and had a friend help me drop the tranny and transfer case out and he unhooked the vaccum lines from the front axle. After the install i hooked the lines back up and they were backwards. My four wheel drive wouldn't work and that's when i heard the pop. I didn't have the transfer case engaged in 4X4 and i heard a loud pop when i was going down the road. I then noticed that the 4X4 light was on. I got back to the shop and turned the boot (that the lines run in) around and the light went off when the transfer case was in 2 wheel drive. Now when I put it in 4X4 it will make a popping noise in the frontend when i drive. What could this be? Please help.

 

Bad u-joints in driveshaft or axles will pop when bad.

 

Been there done that, Check your cad unit on the front axle passenger side. Probably broke the shifting fork, or busted the locking collar on the axle shafts.

 

Mine also pops. I know it is going into 4 wheel drive but it makes a terrible popping sound when moving.

 

About how much money am I looking at to fix this?

 

Make sure it is not your trac bar

Does it do it while turning, while slow or not moving?