98 Elantra wiith NO REVERSE and SHIFTING HARD
 

I have a 98 Elantra with the 1.8 engine. The automatic transmission is
giving me some problems. The orginal Transmission had no reverse and
shifted hard between 1st and 2nd then it would loose connection when it
it 25 MPH. I pulled a transmission from a 97 Elantra and it does the
exact same thing. No reverse and shifting hard between 1st and 2nd and
looses connection at 25 MPH. I even changed the Trans. Computer and it
did not help. If I take the O/D off it will shift hard in 1st to
second and then I got it up to 45 MPH in my back road but it does not
shift again. Then I started from a start and hit the gass hard and
when it was in 1st gear it seemed to drop down a gear like it does when
you floor it. CAN IT BE STARTING IN 2ND GEAR? if so what would cause
this or is the trans mission I got bad as well. ANY HELP GREATLY
APPRECIATED!