Clickity Clank in Reverse - Mercury 115 hp OB 1981

[phoxes]

Just bought a bass boat with above engine. Sat in barn for 2 years without being started. Gave minor tuneup (gear lube, plugs, new throttle and shifter cables, water pump and impeller replacement). Other than a little rough engine in neutral/idle, the thing gets up and goes in forward, and engine hums like its new. But when trying to go into reverse, a semi constant clanking sound comes about. it seems to come and go, but it's there more than it's not. Pretty loud clanking noise if I say so. I'm a newbie so any ideas/where to start would be appreciated.

 

[Dallenx]

Re: Clickity Clank in Reverse - Mercury 115 hp OB 1981

If your model has upper and lower shift shafts then:
When you put the lower unit back on you may have moved the lower shift shaft or upper shifter linkage (or shaft) that controls the f/n/r.
It could be out of position by one spline where it mates to the upper shaft so it's not fully going into reverse.

 

[Chris1956]

Re: Clickity Clank in Reverse - Mercury 115 hp OB 1981

Well, that could be it, but the easier thing to do is to adjust the shift cable. Remove it from the clamp, wiggle the shift arm until it settles into the detent in neutral, and then adjust the barrel nut to fit the clamp.

 

[phoxes]

Re: Clickity Clank in Reverse - Mercury 115 hp OB 1981

Well, that could be it, but the easier thing to do is to adjust the shift cable. Remove it from the clamp, wiggle the shift arm until it settles into the detent in neutral, and then adjust the barrel nut to fit the clamp.

My shift arm has a marking on it designating F/N/R. Looks like this F<-----N----->R It appears that the cable clamp on the shift arm lines up with (N)eutral when I wiggle it back and forth without the cable attached. I adjusted the barrel until it fit with the cable clamp lined up with Neutral marker. I took it back on the water. Now instead of a Clickity Clank, it sounds like a dull ratcheting sound when in reverse, and little to no power from the prop. Does it still sound like a incorrectly adjusted shifter cable? I've seen lots of opinions on how to adjust shift cables, measuring slack, accounting for it, etc. Anyone have a method they have used personally that works? Or does it sound like a gear spline is off? Thanks!

 

[Chris1956]

Re: Clickity Clank in Reverse - Mercury 115 hp OB 1981

The shift arm should be in the center of the shift slider, when in neutral. If it is not, perhaps the upper and lower shift shafts are out of synch, and the control cannot move the gear shifter far enough to engage reverse.

 

[phoxes]

Re: Clickity Clank in Reverse - Mercury 115 hp OB 1981

The shift arm should be in the center of the shift slider, when in neutral.

The shift slider is dead center of the shift arm Neutral marking when in Neutral.

 

[Chris1956]

Re: Clickity Clank in Reverse - Mercury 115 hp OB 1981

well, maybe you have a bad reverse clutch dog. What does the gear oil look like? Any metal chunks?