Force 40 issues

Bob weily

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Jul 18, 2025
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1994 force 40. Fresh water lake. Boat slipped out of forward gear and now won't go back in.

I took the lower unit off, changed the oil, water pump, checked the shift linkage, removed prop and reattached it because thought maybe was a spun prop.
Also turned the prop clockwise by hand and the drive shaft was turning. Reattached the lower unit and still not getting into gear. Been working on this all day for days probably total of 24hrs.

Maybe dogclutch? I don't know ... any thoughts/suggestions?

Also Idle is extremely high.
 

airshot

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Jul 22, 2008
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5,651
You may have answered your own question. "Idle is extremely high", rpm needs to be down around 600/650 rpm of your gonna tear something up, if you haven't already done so. Idle speed is set/ adjusted while underway on the water, not on muffs....
 

Bob weily

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Jul 18, 2025
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You may have answered your own question. "Idle is extremely high", rpm needs to be down around 600/650 rpm of your gonna tear something up, if you haven't already done so. Idle speed is set/ adjusted while underway on the water, not on muffs....
thank you, i adjusted the idle and it's at 650. but still no forward (have neutral and reverse)
 

Bob weily

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Jul 18, 2025
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was it going in forward gear hard before?
No, was running smooth. Not sure how the idle got so high, before it slipped out of gear it was idling around 7 750. After it slipped tho it got almost violently high. I only started once like that (after I reattached the lower unit) and turned it off immediately.
 

Nordin

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Jun 12, 2010
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Usually when slipping out of gear the edges at the clutch dog and even the edges at the forward gear are rounded, but what I understand you do not get the LU into forward gear.
If the clutch dog is worn and the edges rounded it will go into gear but when under load it will slip out.
Try to shift it into forward gear by hand with the remote cable unhooked from the shift lever.
As this engine is very similar to the older Chrysler 45/55Hp the shifting can bind if the remote cables are misadjusted.
The tower shaft can bind cause there is a hook at the shaft that will limit the throttle when you cold start with the cold start function.
If you have a US Marine remote control I think you push in the knob at the center of the handle and move it forward.
If you have a Chrysler remote control you pull the knob at the control box out and move the handle forward.
I suggest you to try to shift it with the remote cable unhooked and check if it will go into gear.
 

jerryjerry05

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May 7, 2008
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Like Nordin said: unhook the cables and shift by hand, do it in the water and have someone helping to turn it off if needed.
IF???? it pops out of gear when the cable is unhooked??? The dog and maybe the gear is bad. Both can be machined to square off themating surfaces.
 

Bob weily

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Joined
Jul 18, 2025
Messages
8
Usually when slipping out of gear the edges at the clutch dog and even the edges at the forward gear are rounded, but what I understand you do not get the LU into forward gear.
If the clutch dog is worn and the edges rounded it will go into gear but when under load it will slip out.
Try to shift it into forward gear by hand with the remote cable unhooked from the shift lever.
As this engine is very similar to the older Chrysler 45/55Hp the shifting can bind if the remote cables are misadjusted.
The tower shaft can bind cause there is a hook at the shaft that will limit the throttle when you cold start with the cold start function.
If you have a US Marine remote control I think you push in the knob at the center of the handle and move it forward.
If you have a Chrysler remote control you pull the knob at the control box out and move the handle forward.
I suggest you to try to shift it with the remote cable unhooked and check if it will go into gear.
Alright thank you, this is what I will try today.
 

Bob weily

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Joined
Jul 18, 2025
Messages
8
Like Nordin said: unhook the cables and shift by hand, do it in the water and have someone helping to turn it off if needed.
IF???? it pops out of gear when the cable is unhooked??? The dog and maybe the gear is bad. Both can be machined to square off themating surfaces.
Thank you, this is what I'll do today
 

Bob weily

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Jul 18, 2025
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1000000662.jpgwhen I hold the shift pin down with my thumb it catches every time. When I don't hold it down, the slightest back turn makes it rise ever so slightly and throws it out of gear
 

Nordin

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As you describes and I can not feel and se you engine it sounds like the edges at the clutch dog and/or the gear is worn.
BUT hard to give a good advice.
 

Bob weily

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Jul 18, 2025
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Thanks Nordin, that's kinda what I was thinking but wasn't sure.
I've gone over and checked everything else multiple times. Now just worried about taking it all apart, never done that before. I think forward gear is all the time way in the back, so think I have to take the whole darn thing out.
 

Nordin

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Jun 12, 2010
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Not really hard to pull apart.
Just to be careful when pulling the propeller shaft cover.
Make a puller for it, do not twist the cover to try to turn the cover a bit and try to pry the cover off with a screw driver at the mounting tabs.
Really large risk you brake the tabs.
 

jerryjerry05

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May 7, 2008
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View attachment 410324when I hold the shift pin down with my thumb it catches every time. When I don't hold it down, the slightest back turn makes it rise ever so slightly and throws it out of gear
View attachment 410324when I hold the shift pin down with my thumb it catches every time. When I don't hold it down, the slightest back turn makes it rise ever so slightly and throws it out of gear
The way it's set up: you'll have to hold it in place . Does it pop out of gear when the linkage is shifted up?
 
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