Mercury 300

[Stingherone]

I have a Mercury 300 Verado 2012.. when I put it in gear forward or Rev it makes a clunking noise..I have only just bought it and wondered if I should be worried by this.. I’m wondering if the gearbox oil would be low..?
Thanks in advance..Rob

[A1an]

Generally outboard gearboxes are pretty clunky when a gear is engaged but we obviously don’t know how clunky yours is. It could be a stretched cable that needs adjusting or possibly your engine idle is a little high. The oil level shouldn’t make that much difference to the gear engagement but it may be worth dropping the oil and inspecting it to give you an idea if there is indeed something wrong internally.

[jakew009]

Originally Posted by Stingherone

I have a Mercury 300 Verado 2012.. when I put it in gear forward or Rev it makes a clunking noise..I have only just bought it and wondered if I should be worried by this.. I’m wondering if the gearbox oil would be low..?
Thanks in advance..Rob

Are you trying it with the boat on a trailer? If so, don't do that.

When the boat is in the water it will make a slight clunk, but nothing to worry about.

[jakew009]

Originally Posted by A1an

Generally outboard gearboxes are pretty clunky when a gear is engaged but we obviously don’t know how clunky yours is. It could be a stretched cable that needs adjusting or possibly your engine idle is a little high. The oil level shouldn’t make that much difference to the gear engagement but it may be worth dropping the oil and inspecting it to give you an idea if there is indeed something wrong internally.

It will be a fly by wire throttle so nothing to adjust. There is an actuator inside the leg.

[A1an]

Originally Posted by jakew009

It will be a fly by wire throttle so nothing to adjust. There is an actuator inside the leg.

I did wonder if it was FBW but guesstimated that maybe at 2012 it wasn’t.

[jakew009]

Originally Posted by A1an

I did wonder if it was FBW but guesstimated that maybe at 2012 it wasn’t.

Fly by wire since 2003 😊

[samt]

It should shift smooth and quiet. Take it to a Mercury/Mariner dealer. Very unlikely to be caused by low oil. Better to get it sorted than run it and blow the gearbox!

It'll be an L6 so the shift actuator will be up top.

If you are running it out the water a heavy stainless steel prop may clunk a bit, and will sometimes ratchet over the clutch at tick over - if in the water you won't experience this.

[Iankristy]

There’s a method to changing gear with a mercury. You need to push gently and it will pause the flywheel and shift into gear. If you try push quickly into gear it will clunk horribly. Try it.