shift dog noise?

[Craig-]

2001 90hp 60 looper

When coming off plane to neutral lower unit clanks like something is riding the gear. Has done this since brand new, at the time dealer said it was normal. Has never seemed to hurt anything down there but is a very annoying sound. Is this hurting anything? Can it be adjusted or do I live with it? Lube always looks good on changes, shifts to forward and reverse just fine.

 

[tmcalavy]

Re: shift dog noise?

Are you shifting it into Neutral quickly or slowly? Always shift quickly and crisply...don't shift slow and grind the gears and dog together.

 

[Craig-]

Re: shift dog noise?

Makes the noise before pulling back to neutral, down to idle but control in forward. Pulling back from go to neutral quickly, just a little clankitty, clank.

Could control cable adjustment be off a little? Too tight or too loose?

 

[F_R]

Re: shift dog noise?

The motor is too new for me, but what you are describing is normal on a lot of motors. Put the control in forward (motor off) and see if you can turn the prop by hand (in one direction, forward). If you can, and it goes clackity-clack, then it is normal. The boat is simply going faster than the motor, and water flow is doing what you are doing by hand in the above experiment.

Then rest well, all is ok.

 

[jonesg]

Re: shift dog noise?

Is that the various bearings unloading?

My old dirtbike would decelerate with a ring adingadingading sound.

 

[F_R]

Re: shift dog noise?

No, it is the ratcheting action of certain clutch dog/gear designs. Instead of the ears being square on both sides, one side is tapered, allowing an over-running condition when the prop is trying to drive the motor. Its purpose is to make more room for the dog to slide into the spinning gear without clattering. Actually, the concept is ancient--going way back into old Mercs and Scott-Atwaters of fifty years ago.

EDIT: Here is a picture of a 1955 Scott-Atwater Bail-A-Matic clutch dog and gears. See the tapered trailing edges? A worlds-apart gearcase design, but there is little new under the sun. BTW, you NEVER saw a worn out clutch dog in those old Bail-A-Matics

 

[Craig-]

Re: shift dog noise?

That makes sense. I think it does spin by hand in gear with a click. I'll double check later. Thanks

Kinda of like an old free wheeling old Saab trany.

 

[Craig-]

Re: shift dog noise?

Put it in forward gear, prop does not spin by hand. It can be moved back and forth about an inch or so. The clang noise that I described is the same when moving it back and forth, a clang at both limits. Turning it hard clockwise turns the motor with much effort. It does spin freely in neutral one direction and click in the other.

Is this OK? On hard deceleration is it just rattling back and forth?

 

[F_R]

Re: shift dog noise?

Holy cow, an inch?? Something is missing. Is it sliding back and forth on the shaft? One of the spacers is missing if it is. Let's hope it is the aft one. If the forward one, and the prop is rubbing on the gearcase, it will eat it alive.

You must examine that thing and see what's wrong. It certainly isn't normal.

Sorry for my original incorrect guess.

It shouldn't be clicking in either direction in neutral. The shift cable may be out of adjustment. But that's a separate problem.

 

[Craig-]

Re: shift dog noise?

Inch in rotation at prop diameter, at shaft 1/8 or so in rotation, not in out. But no click and rotate.

I was wrong about neutral, think it spins free both ways, will double check.