97 Grand Am 5-speed problem

It happens that my 5-speed manual tranny had no oil whatsoever,and what happened gears ground each other.Now after buying another tranny and puting it in I have different problem.When I want to shift into fifth gear ,it will sfift but with grinding noise,only while shifting.Othervise all the gears are ok,except fifth,and fifth is fine only makes noise when shifting into it.