If the trans slips goin into 2 nd gear n 4th gear do i have to replace the trans

Hello,
It would be very uncommon to have to replace the transmission with those issues. What you may consider doing first, if you already haven't.

1. If you were told you need to replace the transmission, that is a very large expense and warrants getting a second opinion. ( I never tell the second place what the first place said, if they both come to the same conclusion it is more likely to be accurate.)

2. Double check the transmission fluid level. If the fluid level is good then;

3. Have the transmission serviced. New fluid and filter can make a big difference. If that doesn't work then;

4. You may want to have the shift solenoid, and possibly the speed control sensor checked.

I hope this helps you.
Donnie