My Mercruiser 140 wont go into gear. please help.

chicubs08

Seaman
Joined
May 20, 2008
Messages
73
I have a 1984 Rinker with a Mercruiser 140. The boat wont go shift into gear. when i put the boat in gear, it will just rev up but the prop will not spin.The prop does lock into forward when the boat is in forward gear and locks into reverse when its in reverse gear and spins freely when its in neutral. What can do causing this problem? is it easy to fix? how much will it cost me to fix? thank you so much for your help.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: My Mercruiser 140 wont go into gear. please help.

The splines may have spun out in the engine coupler. Does the engine overheat when running?
Look behind the engine where the out drive shaft goes into the coupler. Any metal shavings?
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: My Mercruiser 140 wont go into gear. please help.

Sounds like the upper gears could have gone, too. Check oil for metal flakes.

Coupler is the easier fix but still requires pulling the drive and engine.
 

chicubs08

Seaman
Joined
May 20, 2008
Messages
73
Re: My Mercruiser 140 wont go into gear. please help.

I was thinking it was the throttle cable that goes to the outdrive. Could it be? i think see any medal shavings. I also changed the outdrive gear oil and didn't see anything there either.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: My Mercruiser 140 wont go into gear. please help.

I was thinking it was the throttle cable that goes to the outdrive.
The throttle cable goes to the carb, a shift cable goes to the drive. But if it is shifting and will lock in both directions when turning the prop by hand and will spin both ways when in neutral, then the drive is shifting. The problem is the engine is not turning the drive.
Start the engine and look at the drive shaft where it goes into the engine coupler and see if it's turning or not.

i think see any medal shavings.

Huh?????
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: My Mercruiser 140 wont go into gear. please help.

If you're able to shift from the remote throttle/shifter, it's not the cable.

The only thing now is the spun prop hub or coupler. Put it in forward gear and force the prop to turn counter clockwise and see if the prop turns without the shaft turning(spun hub). If it turns and the prop shaft turns, it'd likely the coupler. Both have rubber 'sleeves'.
 

chicubs08

Seaman
Joined
May 20, 2008
Messages
73
Re: My Mercruiser 140 wont go into gear. please help.

The throttle cable goes to the carb, a shift cable goes to the drive. But if it is shifting and will lock in both directions when turning the prop by hand and will spin both ways when in neutral, then the drive is shifting. The problem is the engine is not turning the drive.
Start the engine and look at the drive shaft where it goes into the engine coupler and see if it's turning or not.



Huh?????

i meant to say, i didn't see any metal shavings. But i will check again.
 

chicubs08

Seaman
Joined
May 20, 2008
Messages
73
Re: My Mercruiser 140 wont go into gear. please help.

if it is the ENGINE COUPLER is it easy to change? I found the ENGINE COUPLER for $139.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: My Mercruiser 140 wont go into gear. please help.

if it is the ENGINE COUPLER is it easy to change? I found the ENGINE COUPLER for $139.

You have to remove the drive, then pull the engine. How hard it is depends, on if you know what you are doing, have a hoist to lift the engine out and back in, then it's not that hard.
 

chicubs08

Seaman
Joined
May 20, 2008
Messages
73
Re: My Mercruiser 140 wont go into gear. please help.

I do have an engine hoist. So, i do have to pull the engine?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,095
Re: My Mercruiser 140 wont go into gear. please help.

Ayuh,... The 1st thing to do is,....

Identify the Problem,..... Then worry about Fixing it....
 
Top