replaced water pump on 1979 merc 175 and now shifting hard

I replaced the water pump on my 175 merc and now when going into F,N,R it shifts hard and clunks into gear. When In F prop will not spin CCW, when In N Prop spins freely and when in R Prop will not spin either way. Shift control was in F when I removed the LU and remained that way until I had the LU reinstalled. Shifting into reverse is exceptionally hard. This is also unrelated to the shift cables. Any advice would be greatly appreciated. Thank you!

Re: replaced water pump on 1979 merc 175 and now shifting hard

you cam is more than likely out of line binding the shift shaft hopefully you have not damaged it by trying to hard to shift into reverse. I would suggest you remove the LU and check to see if you cam is in the right positon in reverse Hi spot center of the ^ LU in N mid cam in the center^ of the LU and in forwards ^ low spot in the center of the LU. Because your description of the prop is acceptable that tells me the cam for the lockdown may be off

Re: replaced water pump on 1979 merc 175 and now shifting hard

Thank you for the quick reply, but Im confused by your post. What do you mean by "^ LU" and by the " Hi spots and Low Spots"

Re: replaced water pump on 1979 merc 175 and now shifting hard

LU is the Lower Unit hi spot and low spots are the directional positive positions on the cam for the reverse lock that stops your motor from lifting in reverse. if this was removed during the removal of the LU or the shift shaft was moved to a different position during the removal then thigs are out of line up

Re: replaced water pump on 1979 merc 175 and now shifting hard

Re another post with a great ending : remove the unit when testing to see if your in the right gears spin the prop while shifting neutral spins freely when you shift the shaft to the right it should be in fowards. The prop will lock in one direction and rachet in the other direction going click click click. when you shift the shaft to the left passing neutral you should be in reverse the prop will lock in both directions. Now shift back again one more time to the right to get neutral set your throttle control to neutral and re install the lower unit you should be good to go. You at present may have the LU 180 out of sinc. if you did not remove the cam it will be easier for you to identify the position. when the LU is in reverse the high spot of the cam should be at the front point of the LU Center it lifts the reverse lockdown pin. when shifting to neutral the middle of the cam will be facing the front point center of the LU. When in fowards the lowest part of the cam will be at the point center of the LU facing the boat ^

Re: replaced water pump on 1979 merc 175 and now shifting hard

You said shifting hard is un related to cables,
were they un hooked?
If the shift shaft was in rough shape and
didn't slide cleanly together lower shaft could be
Pushed down and upper shaft pushed up causing a bind.
I think max was referring to a non power trim motor.

Re: replaced water pump on 1979 merc 175 and now shifting hard

Big flop said:

You said shifting hard is un related to cables,
were they un hooked?
If the shift shaft was in rough shape and
didn't slide cleanly together lower shaft could be
Pushed down and upper shaft pushed up causing a bind.
I think max was referring to a non power trim motor.

Click to expand...

posters reply RE:

Thanks again Max, with the description in your first post, I was able to get it back together correctly. I went to the lake and tested:

Re: replaced water pump on 1979 merc 175 and now shifting hard

Big flop said:

You said shifting hard is un related to cables,
were they un hooked?
If the shift shaft was in rough shape and
didn't slide cleanly together lower shaft could be
Pushed down and upper shaft pushed up causing a bind.
I think max was referring to a non power trim motor.

Click to expand...

This is a power trim motor.

What you said makes sense about the shafts not coming together cleanly. How can I be sure they are seated properly? When I installed the lower unit I assumed they would pull together.

Re: replaced water pump on 1979 merc 175 and now shifting hard

You should be able to grab the shift shaft
just above the lower unit & slightly slide it
up and down on the lower shift splines.
Shaft is just above lower mounts, grab it with small vice grips.

Re: replaced water pump on 1979 merc 175 and now shifting hard

Did you unhook the shift cable from the motor
and shift the motor by hand?

Re: replaced water pump on 1979 merc 175 and now shifting hard

Big flop said:

Did you unhook the shift cable from the motor
and shift the motor by hand?

Click to expand...

Yes, the shifting is very stiff at the motor with the cables un hooked.