Sailboat repower with v drive

Discussion in 'Inboards' started by Zappi, Jun 21, 2010.

  1. Zappi
    Joined: Oct 2008
    Posts: 103
    Likes: 2, Points: 0, Legacy Rep: 31
    Location: Puget Sound

    Zappi Senior Member

    Repowering a sailboat on a budget. I just purchased a 34' sailboat that came with an uninstalled volvo md2b, 22 degree v drive, and controls. I think the v drive is original to the previous motor which was a westerbeke 4 107. I realize with out more info and specs on the particular v drive and everything else I can only get general answers.
    My questions are... The v drive has a u joint between the transmission output and v drive input. How true does the alignment of the two need to be? Would it be wise to create rubber bushings between the two and between v drive output and prop shaft? Should I put rubber pads between drive mounts and mount pads or does this want to be solid mount. Not thinking anything big and rubbery, just a little cushion to soak up noise and vibration. Any thoughts and knowledge on this would be greatly appreciated.
     
  2. tunnels

    tunnels Previous Member

    Is the thrust pushing/pulling from the prop shaft going directly onto the Vee drive ?? If it is you'd better make sure its very securely mounted like really good and make sure the vee drive will cope with the thrust , Like does it have a thrust bearing inside of it ?? :D
     
  3. Zappi
    Joined: Oct 2008
    Posts: 103
    Likes: 2, Points: 0, Legacy Rep: 31
    Location: Puget Sound

    Zappi Senior Member

    Thanks Tunnels. Thats something else I hadnt realized. I would say yes the thrust will transfer to the vdrive. Not sure it has a thrust bearing or even how to know. I do believe it was used with the previous engine and existing shaft and prop though. With that in mind... Probably solid mount the v drive with no isolators???
     
  4. tunnels

    tunnels Previous Member

    iTS THRUST IN BOTH DIRRECTIONS DONT FORGET !!. ITS GOING TO BE TAKING THE TOTAL PUSH AND PULL FROM FORWARD AND REVERSE !! :p
    Its amazing the amount of boat builders that dont even think about the shaft as having the total push and pull placed on it !!
     
  5. Zappi
    Joined: Oct 2008
    Posts: 103
    Likes: 2, Points: 0, Legacy Rep: 31
    Location: Puget Sound

    Zappi Senior Member

    I appreciate the input thus far. I haven't gotten any answers to my actual questions though.
     
  6. tunnels

    tunnels Previous Member

    Universal joint with a cross will run about 5 degress ok but the more they are out of alinement the quicker they wear out naturaly . There are many differant types of universal joints , check and see if you can locate CV joints !!
    So from the back of the gear box to the Vee drive it will have a short jack shaft ? if so about how long from one flange to the other ?
    Go chat to a mechanical engineer and you should get some useful info from them . If the vee drive is coupled to the propshaft with a straight coupling then the alignment will obviously have to be the same as the shaft ,rubber mounting i would say NO because theres also the thrust issue dont forget !! not to say you cant use decent rubber mounts for the motor and gearbox and even a rubber semi flexable coupling on one or both ends of the jack shaft .Depending on the length of the shaft it will need a splined slip join as well , Makes life a lot easyer if it has getting it in and or out at anytime also when and if you have to do anywork on the vee drive .
    Post some photos of all you have and where everything is going !! :D
     
  7. Zappi
    Joined: Oct 2008
    Posts: 103
    Likes: 2, Points: 0, Legacy Rep: 31
    Location: Puget Sound

    Zappi Senior Member

    Thanks Tunnels. I'll be going to the boat this weekend and will take photos and post them.
     

  8. apex1

    apex1 Guest

    Find out what V drive that is, then lookup the spare parts catalogues online. That will show you if it is a drive with thrust bearings. Commonly they are, as the gearboxes in the lower power range too.
    The MD2B is just the engine model.

    A simple phone call might be easier.;)

    A flexible coupling between V drive and shaft is common and recommended.

    Regards
    Richard
     
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