Propshaft Repair

tuner

pysgotwyr
  • May 24, 2006
    1,426
    939
    Huntington Beach
    Name
    Steve
    Boat
    260 Mackinaw
    My 98 Mackinaw has a slight vibration just before getting on a plane, I can see the shaft log run-out at this point then it disappears by 20mph. A new prop, new cutlass bearing and coupling alignment to within 0.003" did not resolve the problem. I suspected the shaft may have some run-out but put it off due to the horror stories of coupler removal. Last week, I built a heavy duty puller based on designs for sale, it is 1/2" plate with a 3/4" NF bolt and nut. The coupler pattern for my Liberty 5000 transmission was easy to find and simplified the project. Fortunately for me, with the help of a 1/2" impact gun, the coupler budged and I had the shaft out in about an hour.

    I took the shaft and coupling to Ryan at Wilmington Iron Works for inspection and repair. There was only a small amount of run-out in the shaft to repair then reface the coupling. The shaft and coupling looked great and included new keys, set screws, and paint on the coupler.

    I tested the boat with a different prop ( 17x14 3 blade) vs the previous prop (15x15.75 4 blade). The results were good at low speed but the new prop produced a new vibration or harmonic at higher speeds that was troubling. I have since reinstalled the 4 blade and will retest when weather and work permits.





    Rough looking, but it got the job done!


    steve pixel 3 738.jpg



    Shiny like new!

    steve pixel 3 761.jpg


    The big wheel, I had high hopes for!

    steve pixel 3 757.jpg
     
    Last edited:
    Upvote 0

    Islandrat

    Wish I was new
    Aug 15, 2007
    362
    83
    Camarillo
    Name
    Eric
    Boat
    Davis 22 to Radon 26 to Crystaliner 33
    That looks great. Just pulled my shafts today so I appreciate what u did. Hope u figure out the problem. I will follow
     
    Upvote 0

    tuner

    pysgotwyr
  • May 24, 2006
    1,426
    939
    Huntington Beach
    Name
    Steve
    Boat
    260 Mackinaw
    The big three blade was a bust, it generated odd vibrations in the boat, possibly due to the proximity of the blades to the hull. I plan to take the prop to Wilmington Propeller and have it checked.

    I reinstalled the previous 4 blade Acme and the boat is smoother than ever. The minor straightening and coupler facing seems to have made a significant improvement.
     
    Upvote 0