Talk: Troubleshooting: Drive Trims down but not up

My trim cylinders trim down. At first after sitting all season they trimmed up by themselves. They wouldn't last summer. Now the lower unit will only go up when my son does the up button and I physically help assist on the lift. I do not see any leaks and the motor sounds strong. Does anyone have any suggestions? Emial me at beingtransformed83@gmail.com