Can skeg damage cause vibration/noise on plane?

[void7910]

So Georgian Bay got me yet again. We were puttering down a channel quite slowly (~7-9 MPH) not on plane, when we dinged the outdrive (Alpha, Gen2) off a rock. Middle of the channel but the water is down right now ¯\_(ツ)_/¯ Anyway, I inspected from the swim platform and the prop seems OK, no major damage, maybe a rough edge or two but no chunks missing, curled fins etc, The leading edge of the skeg feels like it's been flattened out a little and has a rough edge, no chunks missing either.

When we got back up on plane there was audible vibration and I could feel it in the wheel. My question is, can skeg damage cause this or is this indicative of prop/shaft issues?

We take the boat out for the season next week, so should be able to get a better look then.

 

[Chris1956]

Is the Prop is made of stainless or aluminum?

If aluminum the propshaft is very likely fine. Perhaps the universal joints are going bad?

If the prop is stainless steel, at that low speed, it would be unlikely the propshaft was bent, however it is possible.

Visual inspection when you pull the boat should tell the tale.

 

[void7910]

It’s aluminum. I refuse to run stainless on Georgian Bay as I value my outdrive.

Noise/vibration started just after the bump. U-joints, gimbal are only 4 years old.

 

[Grub54891]

When you pull out, remove the prop and check the shaft with a dial indicator.

 

[Mad Dog 2]

Props can have more damage then can be seen by eye. If you have a spare prop/get your prop reconditioned and try that before hauling for the winter.
Cheap test and may give peace of mind?

 

[airshot]

Just one blade out of whack can cause a vibration even with no pieces missing.

 

[cyclops222]

Prop substitution test first. with a perfect condition prop.

 

[JASinIL2006]

My money would be on prop causing vibration before I’d consider the skeg. Esp. if the prop is aluminum.

 

[JimS123]

Skeg damage is likely not causing this type of vibration. A bent aluminum prop is the likely cause.

We all have had prop damage. THAT is the specific reason I got rid of aluminum props many years ago. SS will sustain a lot more abuse.

 

[airshot]

Prop substitution test first. with a perfect condition prop.

Right after checking the prop shaft to be sure it isn't bent !

 

[airshot]

Skeg damage is likely not causing this type of vibration. A bent aluminum prop is the likely cause.

We all have had prop damage. THAT is the specific reason I got rid of aluminum props many years ago. SS will sustain a lot more abuse.

Very true but then the damage goes back up the line into the lower unit, which becomes far more costly than replacing an aluminum prop. All depends on how big a gambler you are.

 

[Mad Dog 2]

Skeg damage is likely not causing this type of vibration. A bent aluminum prop is the likely cause.

We all have had prop damage. THAT is the specific reason I got rid of aluminum props many years ago. SS will sustain a lot more abuse.

I worked for a marine contractor for several years. We ran only aluminum props on the outboard powered work boats and I/O boat because the props were sacrificical to protect the prop shaft and bearings. Props are cheaper and quicker to fix then drive components.
Some of the props on the skiffs came back a ball of aluminum.

 

[JimS123]

Back in the '60's I damaged a few aluminum props. Then I bought a depth finder. Not a panacea, but I haven't hit a prop in 40 years.

We do beach on a sandbar almost every time out. Sand can screw up aluminum, while SS won't be bothered.

The REAL reason for SS is the performance that comes with them. For that reason I'll stick with SS.

We all have different likes and dislikes and environments that we boat in. We are blesses in that we have so many choices.