My 280 kicks up in reverse, on trailer I shift into reverse and the jaws/teeth lock onto the lock rod. I pull the drive up by hand, only moves about an inch or two and is locked so tight not even my force can break it. the harder I pull the higher the teeth lock the rod. The whole reverse lock, actuator, springs, teeth purchased brand new and instaled by mechanic who still cant figure it out after 3 sea trials. It only kicks up in the water. The mechanic has given up. We even changed the plunger instlled a new one. This happens only in the water not on the trailer. This is the third year with the third mechnic and same problem. I am confirmimg the drive is completelyin the down position. Can anybody help me out?