Need Help identifying issue with Outboard Motor (Evinrude)

[FishH20]

I am having an issue with my 2009 outboard Evinrude 40HP Etec motor. I am having a clicking noise in the lower unit, at least I believe it to be in the lower unit. As the RPMs accelerate, the clicking noise gets louder. It only makes the noise in the water and not when I have the earmuffs on in the yard. I think it could be a clutch issue but not sure. Any ideas and how to repair/check. The motor runs good other than the noise which sounds pretty bad. I appreciate the feedback.

 

[racerone]

Check gear oil first.-------------Checked shift rod height ?

 

[FishH20]

Check gear oil first.-------------Checked shift rod height ?

I changed gear oil and it looked ok. There were some minor shavings on the magnet bolt but very thin and a small amount. How do I check rod height?