Inboard merc motor .. runs fine but grinds when put into gear.?

Question

Forward or reverse the same thing. Any ideas?

Answer 1

Without being on the boat I have two ideas.

One, you need to be somewhat aggressive putting it into gear. Move quickly and smoothly with the gear shift, and don't baby it. Does it still grind?

Two, I know you said I/B, but do you mean inboard/outboard? My second thought is bad U-joint if it is I/O

Answer 2

This often is a sigh of a starting binding lower shift cable.

As this cable gets stiffer to move, the lash in cable system holds the shift dog in the lower to shift all the way in to gear.

This can be fixed by eighter renewing  the lower shift cable or ..to adjust it.

Here is a link how to..

http://www.sterndrives.com/supplies/mdti...

Frank

Answer 3

Merc's grind in reverse due to a dog clutch, which is normal.  However, check to make sure your engine idle is set to factory specs.  Sometime if the engine idles fast the shift interupter does not function as it should and the gears will grind.  

You didn't give a lot of details so you may find someone in your maria with a merc I/O and let them hear the grinding.  They would probaly be able to tell you if its normal or not.

Answer 4

Need more details.  Model, inboard or i/o, what transmission etc.