87 b2000 trans noise

so the truck shifts and drives well. My only concern is that when its in gear and I let off the gas it makes kind of a scraping noise. Like "chink! chink! chink!" I'm new to the forum and this is my first Bseries looking forward to tinkering with this little guy. I'm not really a mechanic but I'm mechanically inclined. Any advice helps! Thanks

Maybe you have a u-joint bearing (cris-cross) that is starting to run dry. How many miles do you have on the truck. Can you try slowing down in fourth and third as a coast down and see if the truck does the same thing?

check your driveshaft support bearing if it is 2 piece driveshaft

Its got 180k miles, yea it does it in all gears. I can hear it mostly under the cab. Maybe i can capture it on video and post it to youtube later today. And yes it has a two piece shaft.

You probably need to take it somewhere where you can put it on a lift with someone inside the vehicle and someone under the vehicle. It might cost you less in the long run to replace all the u-joints at the same time if that turns out to be the problem.