i just put a b16 in my civic and i took it for a spin for the first time and i was driving once i put it in to second i heard a snap and it dont catch gear anymore and when i put it into gear the speedometer goes to 20 but the car dont move, so i took the cv shafts out and the little gear thingy at the end of the cv shaft was worn out, i looked into the tranny and it didnt seem like anything was wrong, help?

 

I'd start by taking off the tranny if you've already inspected the axles. What kind of shape was the clutch in? Start with that and see what's up.

 

What year Civic?
Sounds more like the axle popped out for whatever reason. Make sure there is a spring clip on the end of both axles and its in good shape.. Be sure the axles fully seat into the tranny. try this and test drive again.

 

yea cuz this happened before on my d series tranny and i didnt know whats up, idk if im putting the cv shafts in wrong or the tranny is just messed up but it just has 35 thousand miles on it so i dont think its messed up i think im just not puttin the shafts in right, hopefully its that reason cuz i dont want to buy a new tranny 96 civic HB with jap b16a