Clunking noise when put in gear forward or reverse not in neutral

[cjames]

2007 df175 750hrs motor ran great for about 4 hours out on the water. On start up to head in could here and feel a clunking noise. In neutral runs good at all rpms.

Get it back home and put it on the hose. Same noise and only when put in gear does it make the noise. No codes and motor seems to be working good.

Check lower unit oil and no metal or water. Pull lower unit off and splines look good. Used flashlight and looked up the mid section and couldnt really see much but there was a bushing on the bottom of the mid unit and it seemed to be in good shape. Don't know where to go now. Any suggestions

[Harper]

Not sure what kind of clunk you're hearing from your description. How fast it is, e.g. something that you would consider comparable to your prop speed (a relatively fast clunk), or something much slower. Also does the frequency increase with engine RPM, or stay the same? Have you tried spinning the prop with the engine off and in neutral? When you say you can hear and FEEL the noise, where do you feel it?

[Lunchmoney]

Could be prop rattle if it only does it in gear and at low rpms.

[Solarman]

Remove prop, connect hose and try again. If still hearing clunking in gear, you should have a reputable mechanic listen to it. Before something gets worse.

Good luck. Post back what you find out.

[cjames]

Thanks for the information so far. The noise stays constant and doesnt increase in sound or speed at higher rpm's. When spinning the prop in neutral it does not make the sound. Or with the lower unit off am I able to duplicate the sound or notice anything out of the norm.

Im going to take the prop off tomorrow and hopefully the hub is the issue.

Thanks again for the help. I'll update after.

[cjames]

Update...

Replaced the gear oil installed lower unit back on and ran it without a prop and there was no knocking / clunking noise in gear. Reinstalled prop and noise came back.

I checked the hub and it looked good. Could this be a lower unit problem? Should I get a new hub pressed in or should I buy a new prop with replacement hubs?

[Solarman]

If you are near a prop rebuilding shop, take the boat there, ask them if they have a similar prop to try, and if you can start it up there to show them.

Or, you could do the same thing at a suzuki dealership where they could tell what the noise might be, and try another prop?

Good luck.

[cjames]

Update...

The lower unit is still in the shop going on 3 weeks now. The drive shaft is on back order. Fishing line cut seal allowing a little water in and caused bearing failure due to rust.

[redlowrey]

Update...

The lower unit is still in the shop going on 3 weeks now. The drive shaft is on back order. Fishing line cut seal allowing a little water in and caused bearing failure due to rust.

''''''I would not have thought you would need a drive shaft.