Odd, bad sound after Tranny Rebuild
 

Recently took the plunge on getting a tranny rebuild on my 1999 Forester. After much debate, I decided I love it too much to get rid of it. The shop also replaced a CV boot while they had it.

Anyways, got the car back yesterday, right at 5pm. As I'm driving away from the shop, I immediately notice a terrible clunking noise when I let of the gas that has never occurred before. I feels like something is clanking together or rubbing. It's very audible.

Driving around and testing more shows that it happens more frequently in lower gears and the engine is under more stress (accelerating then letting off). If I'm super smooth with the clutch or have it neutral, it does not happen.

Tried calling/emailing the shop immediately, but they're closed for the weekend.

The transmission feels great, thankfully. This sound is not good news, in any way. I plan to bring it to the shop on Monday morning when they open.

My main concern is driving it now (only car in my household). Any ideas or advice is appreciated!

possibly loose driveshaft bolt?