[Duckfarmer27]

I have a 30 CCPU that has developed a driveline noise. The truck sat from 1990 or so until last year when I got it running. As it came to me via a nephew from an estate I really don't know the history of any of it. I have removed the gas tank to fix a leak, rebuilt the water pump, rebuilt the distributor, pulled the head because of a leaky head gasket - turned out the head had a crack so another head flattened and installed. Just rebuilt the Marvel carburetor. Probably only a couple hundred miles on it in the past year.

Runs and drives fine. No noise as long as engine has a load on the driveline. Coasting a grinding that to me sounds like either bearing or gear interference starts up and has gotten very loud in a short period of time. Can feel the vibration in both the shift lever and hand brake lever. Noise is the same no matter which gear. Absolutely quiet with a load from the engine on the drive train. Pop it in neutral and no noise. Lube levels OK in both tranny and rear end.

Jacked up the back end. Rotating tires by hand can hear a rumbling noise but hard to isolate - somewhere in rear end.

From researching my available books and on forum I am suspicious it is in the pinion/ring gear. Before tearing into it figured I would run the issue past the experts as I have not found anyone with an issues described exactly like this.

Thanks for any ideas.

Dale