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Grind while shifting

D

Dallasengineer

New member
We have a Honda 135 that started a grinding noise when it goes into gear (either fwd or rev).

Is this caused by a bad controller? It does feel loose. Maybe it’s not slamming into gear distinctly enough?
Or is the lower end bad?
I replaced the lower end fluid and it had metal shavings.

Here’s a video of a couple shift operations, showing the gear shifter. Does the shift operation happen too slowly?
 
The rpms sound excessive to me.

I don't work on these nor do I have the manual but I know there is an idle set screw in the throttle body. Uninformed people will sometimes adjust those when they really shouldn't.

Has it always idled at that speed?

Idle speed shouldn't be over 1k rpm.
after reaching operating temperature.

If it's higher than that, check your throttle control and make sure it's not unintentionally advanced for some reason.

You may need to pull the propshaft holder assembly and inspect the dog clutch.

The corners and ledges of the "castlations" or teeth have to be sharp, crisp 90 degrees. If any "rounded edges" on the clutch and/or gears the transmission will tend to grind when shifting.

See items 1, 7 and 8 in link.


It's important when selecting forward or reverse that it be done from neutral while at idle and the movement of the shifter should be swift. Slowly moving the shifter results in the clutch teeth sort of bouncing off each other instead of quickly meshing. That leads to the rounding off of the teeth and accelerated wear.

It appears to me that you are doing the gear selection motion and speed properly.

So, the grinding might be indicative of wear in the shift shaft mechanism or the shifter/cable. I don't know.
 
I think idle should be about 750 rpm, it is for my 1999 FI 130. What is your ideal speed after a warmup?
 
Sounds like normal shift noise to me, idle speed should always be checked in the water with back pressure, engines will idle a bit higher when out of the water.
 
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