Mechanic Q: Hard Shifting.?

When I put the car in reverse either from park or any other gear, the change is very harsh. The rest of the gear changes are smooth. Recently I got a check engine light and I scanned it It read P0773. and said shift solenoid electrical. what is the repair procedure for this?

Mechanic Q: Oil Choices?

Is 2500-3000 miles too early to start using synthetic blend of engine oils. Has the car been worn in enough for this switch?