So I have an odd rattle coming from my (manual) transmission whenever
I am coming to a stop. It sounds to my relatively untrained ear like the differential pin or something, so I am retiscent about driving the car and have parked it.

Specifically, whether I am in gear or not, and whether the clutch is engaged or not, whenever I release the gas pedal and let the car slow down, I get a grinding/rattling noise. Anyone have any suggestions? Anyone have a 420a tranny for sale in the Seattle/Tacoma area?