Prop Rubs

[koby16]

Hi all,

I am new to boating this year and have found myself needing to install a new prop on my boat. You guessed it, I trash the old one on some rocks.

I have installed the new prop on the outdrive and have found that it is rubbing. It is rubbing on the outside of the prop right where it is inset inside the outdrive and only slightly through about an eighth of a turn. I took the prop out and found there are scratches at the back on the outer ring.

The old prop is doing the same thing and I had only run it for about 2 hours before I trashed it.

It is a Volvo Penta SX drive with a 3.0L. The prop is a Turning Point 4 blade 14 x 19.

Is this normal?

Thank you,
Koby

 

[EricJRW]

Re: Prop Rubs

Does not sound normal, but I'm kinda new to boating too.

The first thing to check is to make sure (if required, not sure if this is true for all applications) that the thrust washer is in place. I've seen times when it gets firmly wedged into a prop, so when the old prop is taken off, the thrust washer goes with it. If you don't know to pull it off and use it with the new prop, the prop will slide too far forward.

The other thing I have noticed is that if a one-piece prop is replaced with a two-piece prop, special additional spacers (should be provided with the new prop) may need to be installed.

That being said, some pictures would also be very helpful.

 

[mommicked]

Re: Prop Rubs

I hate to say it but it sounds like you bent the output shaft when you hit the rocks.better get it checked/replaced or you will do more damage to the lower unit running it bent.also look for cracks in the housing or oil leaking around the shaft.thats real bad $$$

 

[koby16]

Re: Prop Rubs

Thanks for the feedback!

The thrust washer is in place, I had to use a different one with the hub kit for the new prop.

I visually inspected the shaft with the prop off and on by spinning it, and with a wrench held close to the outter edge for reference checking for any wobbling. I am fairly sure it is not bent.

There are no cracks in the housing or oil leaking anywhere.

Any other suggestions?

Thanks!

 

[sethjon]

Re: Prop Rubs

Hi all,

I am new to boating this year and have found myself needing to install a new prop on my boat. You guessed it, I trash the old one on some rocks.

I have installed the new prop on the outdrive and have found that it is rubbing. It is rubbing on the outside of the prop right where it is inset inside the outdrive and only slightly through about an eighth of a turn. I took the prop out and found there are scratches at the back on the outer ring.

The old prop is doing the same thing and I had only run it for about 2 hours before I trashed it.

It is a Volvo Penta SX drive with a 3.0L. The prop is a Turning Point 4 blade 14 x 19.

Is this normal?

Thank you,
Koby

Sounds like the the thrust washer is missing.

 

[sethjon]

Re: Prop Rubs

Thanks for the feedback!

The thrust washer is in place, I had to use a different one with the hub kit for the new prop.

I visually inspected the shaft with the prop off and on by spinning it, and with a wrench held close to the outter edge for reference checking for any wobbling. I am fairly sure it is not bent.

There are no cracks in the housing or oil leaking anywhere.

Any other suggestions?

Thanks!

Make sure the washer is not in backwards.

 

[koby16]

Re: Prop Rubs

The thrust washer is in place.

 

[koby16]

Re: Prop Rubs

Hi All,

Just an update for anyone else that happens across this thread. I read through another poster on another forum that said the prop will center itself once you put some torque on it by using it. I did just that and it seems to have corrected the problem. It seems that after the boat sits for a while things settle out and it begins to rub again, although it is less noticeable now. Perhaps some of the material that was rubbing was just worn off.

I also found a forum posting with several posters that indicated that they were experiencing the same thing on brand new boats.

http://www.marine-engines.net/topics/000382.html?motors

I hope this helps. I have found the users on this forum to be very knowledgeable and helpful to me, so I hope this can help someone else.

Thanks,
Koby

 

[koby16]

Re: Prop Rubs

I actually have an update for my update. This is the final word on this case.

After some closer investigation this spring I found that the circular area on the outdrive where the prop is inset was out of round. I am guessing due to the impact with the rock.

I shaved some of the material out where the prop was rubbing and that seems to have done the trick.

Koby