Lower Unit Reverse Gear Problems

AguaSki

Chief Petty Officer
Joined
Jul 4, 2005
Messages
545
Yesterday when I went to back the boat off the trailer there was a loud clicking noise when I put the motor into the reverse gear. After hearing the clicking noise I moved back to neutral, waited a few moments, and then tried going into reverse. This happened 2-3 times, and then the clicking went away, but then I could not get into reverse. When I moved the control into reverse the engine would just rev but not engage in gear. My day at the lake ended before it started. From home today I disconnected the cable and tried to manually shift into gear. It feels like the shift rod is moving freely. I can get into forward gear easily, and I can tell when I try turning the prop that the motor is firmly in gear. Reverse is a different story. If I just manually shift into reverse and then remove my hands from the shifter, I can spin the prop by hand, but I hear and feel a clank noise on every half revolution. If I try spinning the prop fast, there will a few clinks, and then the vibration from the clink will cause a jump back into neutral. If I manually shift into reverse, and I leave my hand on the shifter to keep tension on the shifter in the reverse direction, I can kick the prop blades with my foot and it will stay in the reverse gear. As soon as I remove my hand from the shifter and I kick a blade, the motor will jump into neutral. This is a 1978 Johnson 140 hp (140TL78C). Is my lower unit hosed? I do have a shop manual, and rebuilding the lower looks complicated. My father is better at turning a wrench than I am, and he seems to think this is a doable job. How difficult is a lower unit rebuild?
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Lower Unit Reverse Gear Problems

If someone has had the lower unit off, it sounds as though they may have turned the shift rod.

If so, you would have to remove the gearcase and reset the shift rod length to spec.

If you have the factory manual, the last page of the gearcase section shows the specification.
 

crabbydad

Petty Officer 3rd Class
Joined
Apr 20, 2009
Messages
75
Re: Lower Unit Reverse Gear Problems

sounds like you stripped the clutch dogs off reverse gear
 
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