Lower unit diagram/shifting question

[heyiou]

Anyone have a diagram for a 72 65HP Johnson lower unit? <br /><br />Also, thanks to everyone who has helped me get this engine to run FINALLY!!! Now if it would just shift into forward <br /><br />When I shift into forward I think I can hear something grinding, maybe the clutch dog? gears? it's not real noticable. I have read a couple other posts where people have switched the forward and reverse gears to at least have forward (who needs reverse anyway). Is that possible? Is it more likely to be the clutch dog than the gears?

 

[heyiou]

Re: Lower unit diagram/shifting question

Oh yeah, reverse and neutral work fine. Hydro-electric shift. Trying a different prop to see if it's slipping. Is there anything keeping me from dropping the lower unit besides the four bolts? Do I have to unhook a shaft or anything?

 

[alcan]

Re: Lower unit diagram/shifting question

You will need to disconnect the green and blue wires at the knife connectors near the exhaust cover, at the powerhead. Then you will want the tie a string to the wires and tape them down smooth. This will help you upon reassembly, To ge the wires back up where they belong. If you don't have a manual for this type of work, you should. Making a small mistake can cost you some big bucks. Not to mention they will save to tons of time. This l/u should be in forward all the time unless it is shifted to neutral or reverse with the motor running.

 

[heyiou]

Re: Lower unit diagram/shifting question

It does shift into forward when off...when I turn the prop by hand the flywheel and all moves...seems solid...but when running it doesnt even seem to engage the prop. Could this be a problem with the switch in the controls?<br />Shifting into forward when ignition is off but not shifting into forward via the switch?

 

[Bass Runner]

Re: Lower unit diagram/shifting question

Sounds like the solinoid to me, when you power up it pulls it out and then when you put it in forward on the control it dosn't move it back in gear, or it might be the forward clutch spring is broken.

 

[Joe Reeves]

Re: Lower unit diagram/shifting question

In a test tank, or having the boat at some location where there's no possibility of causing an accident, do the following.<br /><br />Momentarily disconnect the wires leading to the lower unit. That should have it permanently locked into forward gear.<br /><br />Start the engine. If the unit is in forward gear now, there is nothing wrong with the lower unit. The problem would be caused by mistakenly having voltage applied to the shifting wire(s) when the shift control is in the forward position.

 

[heyiou]

Re: Lower unit diagram/shifting question

Thanks for the ideas, I was just about to tear into the l/u but now that I think about it, it may be something easier like the switch or something. If it was the forward spring it wouldn't lock into forward when the key is off, correct?

 

[ddaigle]

Re: Lower unit diagram/shifting question

heyiou, I have a 72 lu that i tore into down to the bare case several times and finally fixed shifting problem. Good advice to check wires first. If in forward at rest spring is probably ok. My problem was similar to yours. Let me run through my 2 week ordeal and maybe save you some headaches. Check wires and solenoids first. I thought my solenoid was bad but it turned out to be a broken wire down by the water pump. It seems that the lu can pinch the wire if your not careful reinstalling. Check wiring all the way to solenoids if possible, this saved me several hundred dollors in solenoids. If wiring and solenoids check out ok you will have to tear into lu. My problem was that a thrust washer had broken and little tiny pieces of metal had gotten into the hydro pump. This caused just enough interference to keep the shift piston from going in all the way. It would catch the very edge of the clutch dog when the motor was off but when it was running it would let go and no forward. Hope this helps and sorry so long, but i went through weeks of problems trying to figure this out.

 

[heyiou]

Re: Lower unit diagram/shifting question

Thanks for the reply, hey I like the long descriptions always helps. I will be sure to check the wiring tonight.

 

[Bass Runner]

Re: Lower unit diagram/shifting question

Just had a thought, don't know which of the wires is the forward but you might do a voltage test at the spade connectors when you put it in forward one should be hot then when you shift to rev. the other should be hot.

 

[Dhadley]

Re: Lower unit diagram/shifting question

Bass Runner -- this is a hydro-electric unit, not to be confused with a straight electric shift.<br /><br />On this model, power to neither wire is forward. Power to one wire is neutral. Power to both wires is reverse.<br /><br />The whole design is so simple that it can be confusing.

 

[heyiou]

Re: Lower unit diagram/shifting question

Yeah I'm hoping that since it locks into forward when off but never seems to even engage the prop (forward) at all when running that it's just wiring/solinoid/switch.