no reverse after rebuild

[power7326]

im stumped. i just finished doing a full rebuild on my 722.418 transmission and replaced all the clutch plates and seals . and replaced the b1 band. upon testing going through all the gears to make sure engagement is good before i let the car down. all forward gears are good except no reverse, it bumps as if it is engaged but tires wont turn ? when i accelerate it sounds and feels like its being brake torqued? any suggestions ideas. i know im gonna have to take it back out, im just wondering if anyone may know where i screwed up. help!!b it came out of a 92 300d 2.5 turbo