You should get you transmission looked at by a qualified mechanic if you think there is a problem. Transmission replacement isn't cheap. I had the replace my Hurth on my 32-3 (1987) with a Beta Marine transmission which works great BTW. As for getting your boat into the slip, may I suggest that you back your boat in all the way without changing to forward and reverse so much. I don't know your situation but if your setup like I am here is what I do. My slip is about half way down the fairway on my dock. When I approach the marina I position my boat about 50 to 60 feet away from the entrance to the fairway, with the marina to port, and at a slight angle with the stern pointing towards the opening, a little. At this point the boat has almost stopped it's forward movement. Then I change to reverse and quickly increase engine speed (again, IN REVERSE) for about two to three seconds which "prop walks" the stern to port and towards the opening to the fairway. At this point I am standing not behind the wheel but turned around, 180 degrees, facing the stern (in front of the binnacle) with my hands on the wheel. In other words I'm steering the boat facing backwards. Try it a few times. After you get use to the transmission and engine controls being backwards maneuvering the boat this way is easy, at least for me. I then steer the boat with very little or no throttle (idling) with the transmission in reverse. I'll slip the boat out of reverse if I feel that I'm going too fast or give a bit more throttle depending on how the wind is accreting the boat. By the time I get to turning and backing into my slip I'm out of gear with the engine idling. If my "first mate" is with me she ties off a spring line to the mid cleat . If I'm solo I can easily stop the boat by slipping into forward and giving it a bit of throttle. This give me time to attache the spring line. Then I slip into reverse, at idle, and the boat moves deeper into the slip until the spring goes taut. Then back in neutral and tie off the other dock lines. I never go faster then I would like to hit something. Slow with control is the key and I'm not going into forward and reverse that much. Takes a bit of practice but works without a hitch for me almost every time with the occasional error on my part which is still easy to control.