View Full Version : Vibration after hitting submerged stump

06-24-2007, 12:03 PM
I'm new to the DD boats (07 Mobius LS). Yesterday I hit a submerged stump. I've done this before with stern drive boats and it just messed up the prop. When I did it yesterday with the DD I figured it did the same thing since the boat would vibrate after idle speed. I was able to get back and load on to the trailer. After pulling out of the water I inspected the prop and there appeared to be no damage to it. My question is could I have gotton the DD out of balance? Any info or advice would be welcomed.



06-24-2007, 12:57 PM
i would take another look at the prop and the prop shaft to ensure you didnt bend it

06-24-2007, 01:59 PM
I agree - it takes VERY LITTLE to get vibration. Have the prop resurfaced & rebalanced, or replace it and use this one as a spare.


06-24-2007, 03:22 PM
If you have vibration more than likely the prop has been bent. The naked eye won't catch the minor bends but when the prop is turning at a high speed you'll feel the vibration.

06-24-2007, 09:14 PM
Thanks, I'll take another look at the prop.

06-25-2007, 08:47 AM
Take a look at the strut (brass hanger that the drive shaft goes through)
I would even hookup water, start the boat, and put it in gear. Then take a look at the prop/shaft, if the shaft is bent you will see it for sure.

All else fails take it to a shop. Don't mess around with a vibration!

06-25-2007, 09:03 AM
I checked the saft and strut, even put a level on the shaft. Both seem ok. Had a friend take a look and he thought that the prop may have a slight bend to it. I'm going to contact the dealer today and see if they can take a look at it. :shock:

06-30-2007, 10:42 AM
As you have already read, I too am in the same boat. got the new prop from Joe Techie and love it..> I still have some vibes/high pitch squeal at low rpm. When we go to neutral and slow to stop, there is a high pitch squeal as the shaft stops spinning. I am confident it is in the Brass strut that supports the shaft just before the prop.

MY Question is: Is there a bushing or packing in that STRUT that is replaceable or is there some maintenance that I should do to that piece?

I think I have found the answer, http://www.skidim.com/prodinfo.asp?number=SB10X12
How do you remove / replace?

Thanks and Happy 4th,

06-30-2007, 09:05 PM
I made the 2 1/2 hr drive this morning to the dealer and picked up a new prop. Left the old one with him, he couldn't see any damage either. Put the new one on and everything is back to normal, no vibration. Going to have dealer send old prop to shop for repair and then I'll have a spare. All is right with the world again. :D :D :D

07-01-2007, 05:53 AM
There is a cutlass bearing in the prop shaft strut that can be replaced.

07-01-2007, 10:35 AM
Thanks Butta... IT seems that there are 2 Allen screws on the strut that hold the bearing in place. That seems like the easy part. Obviously, I have to take the prop off...Can you remove replace the cutlass bearing without removing the shaft, or is that required... Shaft removal will be the deciding factor of go to the shop for repair or do it myself!!! I have my limits! AHAHA :lol: I have found a bearing on skidim.com but am now stuck wondering how to replace.. Rode again yesterday and the vibration quits once you get over about 10 mph... no vibes at towing speed... I know I gotta get it fixed.. hate to give up any riding time!!

Thanks for the help.


07-01-2007, 10:57 AM
Give the people at SKIDIM a call.They have always been very helpful and knowledgeable with any questions I have for them.

07-02-2007, 05:17 AM
Never done it, but I believe you gotta pull the shaft to replace those.

07-02-2007, 07:07 AM
Thanks Butta/SeanPatsDad...
I will talk to SkiDim today and make sure.. I figure this might be time for the boat dr... not me... Not sure if I'm up for shaft removal..