Hard Shift into reverse and park
 

long story short, squirrels got under hood and nested, ate vacuum lines and various other wires. Mechanic said shorted my computer which he replaced. When I drove it back all was well except a little hard shifting from 1st,to 2nd to 3rd. Didn't think much about it since it has set up all summer. Today I drove a pretty good bit, the longer I drove it the harsher the shift became, especially from park to reverse then to drive and then same back to park? Any suggestion? Did he miss a wire somewhere or is there a slight adjustment that I can make to smooth this out. I'm hoping transmission is not the problem. Thanks for any input.