In need of expert help!
The reason for my thinking is because 1st gear shift real hard and wont shift until about 2500 rpm. It had a recent rear tranny seal bad so I replaced it. it was 2 quarts low on fluid and didnt know if fluid was full synthetic or not. I ended up putting reg tranny fluid in it that O'reilly Auto's computer recommended. Do you think a fluid flush and filter change fix my problem? Any help would be greatly appriecated!

