I hear gear grinding noises when I engage in first and second - does that mean I am low on transmission fluids? I do have a rear transmission oil leak on my car that needs to be fixed

 

grinds when you shift up or down from first to second? sounds like worn synchro's. fix the leaks and change the fluid and hope that you did not ruin the transmission. small things like leaks can cost big money if not fixed quickly.