clanking noise in 4wd

[Cornfield creations]

This is really bugging me and it getting cold, so that means snow, and I can't drive this thing down the road like this.
76 k-10, 350/350/203/12 bolt- dana 44
The 203 is converted to part time prior to purchase.
We put a new u-joint in the front axle, the other one is ok for now, New hubs up front, driveshaft is ok, tried a rebuilt still made the same noise.
When it is in 4wd I makes a loud clanking noise, can't tell if it's the front axle or the transfer case. Does nothing in 2wd. When you turn the wheels it makes it more often. When it makes the noise it kinda skips, kinds like when an engine backfires. We thought the cv was bad in the front driveshaft but that wasn't the case. It's kind of a hollow sound but in definately on the right side of the truck.

I was thinking a chain slipping in the transfer? I am gonna pull the fron dif. cover off again, (just had it off and looked ok), but I am gonna double check it. Does anyone have any idea what it could be?

 

[guido666]

Could it be broken shaft? Try engaging just one hub and go for a drive. Then the other. I would say to play with it this way in both 4WD and 2WD but with a full-time case, you don't have a choice. Maybe try taking the driveshaft off and then do it again, also with both engaged. See if you can narrow down the problem to a specific area or more specific circumstances. This will help you locate the trouble.