After I installed the tranny and driveshaft, I get this very intermittent grinding sound. Its not necessarily a rattle, it sounds more like a quick, repetitive grinding sound that only happens for a second, tops. Most times it only happens after I get on it a little bit, and then let off. A split second after I let off and begin to cruise or coast does it make this noise. And it only happens like every 10-ish miles, I can't get it to repeat at will.

I have crawled underneath and shaked/shoved/tapped on everything from the engine back and am still left scratching my head. Ideas?

 

carrier bearing? my dads did the same thing. it was intermittant, and would do it on decel. replaced carrier bearing and noise went away

 

It is the carrier bearing. I looked before but didn't notice. On closer inspection, the dust shield hits a little metal tab when the driveshaft articulates after a release of load. I am going to try to shim it so that goes away.