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1968 Johnson 55 HP

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Pent11

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I have a 1968 johnson 55hp that shift good on muffs, but once put under load it won't shift until the rpms are really high then it slams into gear. I was thinking it was the clutch dog. any suggestions are greatly appreciated.
 
Hm.m.m., have to put on the old thinking cap about that one. I can imagine how it might need high rpm to go into neutral or reverse, but not forward. All I can come up with is a broken shift switch arm in the remote control. But that doesn't explain why it shifts on muffs.

When is the last time you changed the gear oil? Those things demand clean oil or the shifter piston in the oil pump may stick. In any case, it sure can't hurt to change the oil. Use OMC/BRP Premium Blend Gearcase Oil.

Unless it is grinding before it slams into gear, I don't believe it is the clutch dog.
 
Another wild hair idea. The 55 has a spool valve on the bottom of the shift solenoid plungers. If it or the plungers are dirty/rusted/crudded up, they may be sticking until increased oil pressure helps push them open. That guess and $1.79 will get you a cup of coffee at the local gas station.
 
The lower unit needs to come apart for inspection / repair before more damage is done.-----As said the bore for the shift piston is dirty / scored / damaged or the valve pieces mat be damaged.-----May be difficult to find a shop to work on it.------Easy fix on my workbench.----But you opinion may vary !
 
So i just took the whole lower unit apart cleaned and replaced all the old oil seals, I could take the solenoid apart again again to see any damage i was going to take the gears out to see if i put the dog clutch in backwards.
 
It has not worked since i got it, my brother bought it and it just fell into my lap I'm trying to get this thing going since it was free. it just docent make sense it shift fine on muffs but as soon as theres a load it won't engage till it at high rpms and it slams into gear it just seems like the dog clutch.
 
It just takes a wee bit of engagement to drive the prop with no load.------I say the bore for the shift piston is the likely culprit.-----Easy fix in my book.------But some say I have a different book and electric shift is easy in it..
 
racerone said:
It just takes a wee bit of engagement to drive the prop with no load.------I say the bore for the shift piston is the likely culprit.-----Easy fix in my book.------But some say I have a different book and electric shift is easy in it..
Click to expand...

Lol ya I hope thats what it is. What part would I need in order to fix this issue the diagram in parts is a little hard to understand.
 
If its any help Pent11 I have a Johnson 55HP 1980. Quite similar to yours (a tiny bit "younger"). I had the exact same problem where it would change gears fine into reverse on muffs but not in the water. I couldnt for the life of me figure out why putting it in the water has an affect on that, but put it down to some kind of additional pressure being forced onto the unit in some way when in water (? anyone more experienced here know why this can act differently in water to outside on muffs?).

Anyhow if it helps, I took apart the gears and found the clutch dog was quite badly worn as was the reverse gear. So was as simple as that (I think... though i'll know by next month when I get it back in the water to test!).

I would definitely go ahead and take the gears / dog out to inspect that as if its been grinding a fair bit its likely worn at least the dog and probably the gears too.
 
Sorry----There is no comparison between the 3 cylinder electric shift 1968 model and a 2 cylinder 1980 model with mechanical shift.
 
Ah ok. Apples and oranges then I guess.

Any ideas why the reverse seems to work out the water but then not in? Ive been scratching my head on that one.
 
Ya I took it apart and and the clutch dog and gears are all worn out. Just going to replace the gears, dog clutch, and the oil pump. Found all the parts new for $140
 
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