Originally Posted by aharris
Hello all, had my rig in 4x4 last night and noticed a bam bam bam sound as I drove. It was random every few seconds and stopped once I took the truck out of 4x4. No excessive turning, etc. just straight line in the snow driving. It's an auto trans 5.9 truck.
Well obviously something wrong in the transfer case, my guess is probably a slipping chain or broken clutch possible an overrunning clutch. I only rebuild 2wd models and have almost no experience with the transfer cases, but just putting in my 2 cents. To be honest anything can make a bang noise, best way to find out what is really going on is to take apart what you think is the source of the noise and it seems to be the transfer case.