not shifting correctly after water pump replacement

Joined
Sep 15, 2008
Messages
24
Ok so i replaced the water pump impeller on my 1966 merc 350 35hp. I removed the LU with it in neutral. I guess i moved something by accident while replacing the WP because it wont shift correctly now. So i have lowered it back down 3 times and moved the shift shaft on the lower unit and on the controller. So its all out of whack now and it still doesnt work right. Whats the best way to get this right since i messed it all up? Right now the prop turns CCW and it ratchets CW, so im guessing its in reverse. i move the controller to F,R,&N and nothing changes with the prop. Thanks In advance for the help.

Donnie
 

MadProps

Seaman Apprentice
Joined
Jul 3, 2008
Messages
34
Re: not shifting correctly after water pump replacement

when you removed the lower unit did you remove the shift shaft from the lower unit?
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: not shifting correctly after water pump replacement

Hi RD13,
Here's my method for lining stuff up. Find neutral on BOTH upper and lower. In neutral on the unit you'll find the detent in the shift cam and the prop will spin freely. Depending on how much wear is on the cam, it may want to bump into forward, so keep an eye on it. Reassemble at that point. Make sure the reverse lock cam is aligned as per the manual, otherwise the motor will kick up in reverse.
- Scott
 
Joined
Sep 15, 2008
Messages
24
Re: not shifting correctly after water pump replacement

Yes i did pull the shift shaft out, but i thought i got it back in correctly but obviously not. so i guess im gonna pull the prop shaft out and see whats goin on with the shift cam. i have a seloc manual for this motor but it covers too wide of a range of motors and it doesnt show mine in there. If anyone has an exploded view of this lower unit, i really need it. This is the first one i have ever pulled apart. Im pretty mechanicly inclined, i would just like to know what im getting into before i go pulling stuff apart. Any advice or pictures would help. Thanks Again
 

The_Kid

Chief Petty Officer
Joined
Apr 18, 2008
Messages
447
Re: not shifting correctly after water pump replacement

Here are some pics and instructions that might help.
 

Attachments

  • Screen 00001.jpg
    Screen 00001.jpg
    31.2 KB · Views: 0
  • Screen 00002.jpg
    Screen 00002.jpg
    10 KB · Views: 0
  • Screen 00003.jpg
    Screen 00003.jpg
    10.6 KB · Views: 0

MadProps

Seaman Apprentice
Joined
Jul 3, 2008
Messages
34
Re: not shifting correctly after water pump replacement

yeah I thought you may have pulled the shaft, even if you weren't in neutral up top and in the lower unit you would have some sort of gear selection maybe forward, neutral but no reverse or reverse neutral but no forward
the fact you have no gear selection....

remover the lower unit again....turn the shift shaft you should feel resistance and a positive engagement as it shifts into fwd reverse or neutral....the prop shaft should respond by turning in one direction then freely both directions for neutral and then in one direction again but the opposite of the first gear selection....if you cant get any changes in gear selection on the prop shaft or feel the shift shaft clicking into the shift cams detent...then

sounds to me like the shift cam has moved and your shift shaft is no longer in the cam, this would require disassembly of the lower unit completely to put the cam back in place....OR.....

on one old Merc I had this happen so I drained the lower unit flush with kerosene or paint thinner, drain completley....the cam will now move around more freely
shake the unit around till you can get the cam in place , use a long screw driver to center the cam in position and very carefully replace the shift shaft
I cant say this short cut will work for you buts its worth a try

good luck to you
 
Joined
Sep 15, 2008
Messages
24
Re: not shifting correctly after water pump replacement

Yea i tried that with the long screwdriver deal. I got it back into the cam, but still couldnt get it to go in any other gear. It was working before i pulled the shaft out of the LU, so i know something is out of place somewhere. Im thinkin its that spring that i see in the exploded view. Gonna try to pull it apart tonight. Thanks for the exploded view.
 

MadProps

Seaman Apprentice
Joined
Jul 3, 2008
Messages
34
Re: not shifting correctly after water pump replacement

in that case disassemble LU & look into the shift plunger pin
 
Joined
Sep 15, 2008
Messages
24
Re: not shifting correctly after water pump replacement

Yea thats what i meant, the plunger. I was looking at my manual again and it shows a spring there. I wish i had a book for my specific motor, the seloc book i have covers like 65-91 all 1 & 2 cyl.
 
Joined
Sep 15, 2008
Messages
24
Re: not shifting correctly after water pump replacement

Ok so i pulled the LU apart yesterday, and sure enough there lays the plunger down in the bottom. Got it all back together, just gotta get a prop and im goin fishing. Thanks for all the help.
 
Top