Logo
FULL SITE MENU

Grinding when put in forward?

C

Contusioncharger

Member
I have a 1971 Johnson 125hp. Hydroelectric shift. Last night I went out on the lake. I stopped the boat to look at the comet. It started fine and went on my way. I stopped at a friends house. When I left, started and backed out. Went to go forward, I had no forward just rev’d. I unplugged the solenoids wires and it started in forward and made it back home with no issues.

I just took apart the remote control, thinking it was the switch since it will go into stay in forward. The switch ohm’d out good. I started it and moved the switch with my finger. Neutral is neutral and it going into reverse. But it will not go in to forward. And has started to grind. With the switch unplugged it will stay and start in forward. Since it goes into neutral and reverse. It seems like the solenoids are working. And hydro pressure to shift out of forward when it starts. What could it be? If I unplugged the switch awhile it’s running in goes into forward fine. Any suggestions to what I can look at?
 
I can rebuild your unit without looking in a manual.-----There is no power to the solenoids to get forward.-------A spring moves the clutch dog into forward gear.-----I say the bore for the shift piston has dirt embedded in it and the spring can not overcome that dirt !----Easy fix here on my work bench.
 
Yea. Everything electrical is working. I can start it in gear. Shift in neutral just can’t shift back to forward after. I can go from reverse to neutral no problem. Can you explain why it would spring back without the engine running, but not with it running? If it’s dirt then the piston is not closing off neutral completely till I stop the engine from spinning?
 
I would agree, it might be dirt. But no way would I go into that without checking the electrical system. Use jumper wires at the motor to make it shift---if it will. Do it repeatedly.
 
fdrgator said:
I would agree, it might be dirt. But no way would I go into that without checking the electrical system. Use jumper wires at the motor to make it shift---if it will. Do it repeatedly.
Click to expand...

as I said I have checked the wiring. Using the T/S in the manual. I shift in neutral when started. It shift in reverse and back to neutral. It tries to shift in forward, but grinds. If I start in forward it’s in forward and will go to neutral, I can’t not go back to forward. I ohm’ d the switch and checked power. The switch operates normal. I’ll try and change the gear oil.
 
Actually I just move the Throttle back and forth about 20 times. Started it and it went to forward with little grinding. I kept going forward to neutral several times and it got better. I think I’ll still change the oil though.
 
You are not doing what I suggested. Maybe I didn't make myself clear. Locate the blue and green shift wires at the powerhead and disconnect them. Since it takes electricity to get it out of forward, and you have no electricity (wires disconnected), it should be in forward, running or not. And not grinding, if running.

Second step: Connect a jumper wire to the battery +, and touch the other end to the green wire leading to the lower unit (motor running). Should instantly go into neutral. Disconnect jumper and it should instantly go into forward with no grinding. If it doesn't pass, there is a problem in the lower unit, typically sticking piston in the oil pump, but not always.

Third step: Repeat test, this time touching jumper to both blue and green wires at the same time. That will make it go into reverse. Disconnect jumper and it should go into forward with no grinding.

Try it several times, FNR, till you are sure.

Common problem in lower unit is microscopic grit jamming the piston in the oil pump. When that happens, unless you are lucky, you won't unjam it without taking it completely apart.

Moral: This illustrates why it is mandatory that the oil be changed as regular maintenance. By microscopic grit, I mean the by-product from normal wear and tear (the stuff that makes the oil turn black).
 
You’re not reading what I said, in the first post. I did do that. I checked all the wiring, switch and Solenoids before I posted here. And did what you said going FNR with just the key on got it unstuck. Thanks.

I change the oil every 100 hours. It’s been 50.
 
Back
Top