Shift Pivot Screw

[am]

Hello, I made the mistake of removing the shift pivot screw when trying to drain the lower unit oil, and I was able to put it back in. But now I'm worried that I messed something up. The motor still go's into gear (forward and reverse) and will spin freely in neutral. Does that mean that I got lucky, or did I mess something up I cant see? Thanks!

 

[roscoe]

Re: Shift Pivot Screw

Many have done the same thing.

Was the prop, or shifter moved while the screw was out?

Many have gotten lucky, if nothing was moved.

Some thought they were ok, but have had the lower unit shred after an hour of use.

The only real way to be certain, is to remove the lower unit, and have a look inside.

Depending on the make, year, and model, this can sometimes be done very easily.

 

[am]

Re: Shift Pivot Screw

Thanks! I did spin the prop, it locked and that was how I noticed I did something wrong.

I guess I should have a look inside; It's a 1983 75 hp, do you know if that is one of the easy ones to do? I'm just not sure if could see all the way down there without pulling alot of parts out.

 

[Frank Acampora]

Re: Shift Pivot Screw

Try shifting through the gears several times and spinning the prop with each shift. If it functions correctly; ie. locks up in gear and stays free in neutral, you got lucky.

That screw locates an L shaped yoke which is attached to the shift rod on one leg of the L and the shift shaft inside the prop shaft on the other leg of the L. If you did not try to shift the engine with the screw out, That L shaped yoke probably did not move, and you should be OK. You did leave the white nylon seal under the head of that screw on, didn't you? And you did tighten it well to prevent infiltration of water?
As far as opening that lower unit to check, If it is the one piece lower unit and you have not done one before, it will be a little difficult for you; If the lower unit is shifting correctly, I would not open it.

 

[roscoe]

Re: Shift Pivot Screw

You may have gotten lucky, don't know.

You should be able to see inside that lower unit, from the top down.
It helps to have a really good flashlight to see down in there, maybe one of those with the light on the end of a flexible wand.

Drain the lower unit.
Remove the lower unit.
Remove the water pump.
Then remove the gear housing cover bolt ( the torpedo shaped plate) and lift it off. This does not require disassembling any of the internal parts, just removing the water pump and the cover.
Then look down along the shift rod and inspect for proper alignment and operation.

Might as well replace the water pump impeller while you have it apart.

Here is a diagram of your lower unit, compliments of mercruiserparts dot com.

 

[Frank Acampora]

Re: Shift Pivot Screw

Oops! Chalk it up to a senior moment! I completely forgot about taking off the top plate. And I am currently rebuilding a lower unit. Doh!
With the oil drained you will be able to see the yoke, and if it is on the pivot screw. You will also be able to see if it is on the small yoke that rides in a groove on the shift shaft. Once you look in there, you will see why down is forward and up is reverse.

 

[am]

Re: Shift Pivot Screw

Thanks! Everything seems to shift fine, so I think I will just leave it alone. I had the water pump replaced last season, that is the main reason why I would rather not take it apart.

Also if something was to happen would there be a major problem, or would the motor just not shift?

 

[Frank Acampora]

Re: Shift Pivot Screw

If you had a problem with the shift yoke having moved when the screw was removed, most likely the small yoke would fall off the shift shaft, so the engine might go into reverse but would definitely not go into forward, That small yoke is too big to get into the forward gear tapered roller bearing, so in all likelyhood, it would just stay in the nose and no damage would be done.