340 Drive Train

Discussion in 'Sport Cruisers' started by Tacoma290, Nov 19, 2019.

  1. Tacoma290

    Tacoma290 Active Member SILVER Sponsor

    194
    Oct 5, 2006
    Tacoma, WA
    340 Sundancer 2007
    Twin 8.1S V-drives

    Up for Sale:
    290 Sundancer 2000
    Twin 5.0L EFI Bravo Drives
    Looking for advice to make sure I am heading in the right direction regarding the drive train for a new to me 2007 340. Had the boat only 4 days and took it out, only to have a sudden vibration come on at any revs over 2000 rpm, port side. Did not see any debris in the water. Was leaking at the shaft. Major bummer.
    Have pulled the boat, and it is now on stands on the hard.
    Pulled the prop and shaft. Discovered that the body of the Tides shureseal was cracked; ordered new body including the new seal. Found a small imperfection in the propeller and had the prop trued. Ordered a new cutlass bearing.
    On assembly, my mechanic noted that the shaft and the shaft log no longer line up. Aligns off to one side rather. V-drive transmission hasn't moved. He feels the shaft is straight, but now is looking at the strut. Thinks it may be bent. Seem correct? Can the strut be repaired/straightened, and how is that done? Anything else I should be considering?
    Thanks,

    Michael
     
  2. Woody

    Woody Well-Known Member PLATINUM Sponsor

    Nov 20, 2007
    N. Wisconsin/Lk Superior
    2005 420DA
    Cummins 6CTA8.3
    Like props, the shafts, rudders, and struts can be repaired. I'd start with the prop shops in your area. If they don't do it they likely can tell you who does.

    FWIW, there have been many CSR members that have found the cause of vibrations, even funny transmission sounds, has been an engine that needs a 'tune up'.

    Is this the first time you've run the boat? Was it sea trialed, how did it run then? If everything was fine until it wasn't it sounds like you may have hit something. I'd look at the strut mount to the hull, bolts tight? any sign of movement/damage? If strut damage isn't obvious I'd start with having the shaft checked for straightness. What does the wear in the old cutless brg look like?
     
    cfd95 likes this.
  3. Tacoma290

    Tacoma290 Active Member SILVER Sponsor

    194
    Oct 5, 2006
    Tacoma, WA
    340 Sundancer 2007
    Twin 8.1S V-drives

    Up for Sale:
    290 Sundancer 2000
    Twin 5.0L EFI Bravo Drives
    Thanks for the reply, Woody. Boat ran great during the seal trial, and from the Previous Owner's slip to mine. The vibration showed up at once, on the first trip out with my family.
    The misalignment is significant (1/2" to 3/4" according to my mechanic), so it is not likely due to simply being out of the water that is causing the misalignment.
    Strut is bolted and feels solid, with no visible signs of movement.
    The cutlass bearing did show uneven wear (more on one side than the rest of the bearing).
    My mechanic has stated that the shaft is straight, so we are looking at the strut. It doesn't look easy to pull (may need to remove portions of the exhaust to access from the top side).
    I suspect we've all been there in our boating 'careers' but I am not happy at this moment.
    I still wonder how a strut can be straightened without being on the boat. And I hope I am not missing something.
     
  4. Tacoma290

    Tacoma290 Active Member SILVER Sponsor

    194
    Oct 5, 2006
    Tacoma, WA
    340 Sundancer 2007
    Twin 8.1S V-drives

    Up for Sale:
    290 Sundancer 2000
    Twin 5.0L EFI Bravo Drives
    Well, got word that the strut is indeed bent. Pulled it and sent it out to one of our better prop shops in Seattle, and they stated it would not be advisable to re-bend it. Sea Ray part 1603547 but they don't normally carry. Casting part appears to be 25564. The prop shop says they can locate one on the east coast. Not cheap. Any other sources for replacement?
     
  5. rmlsll

    rmlsll Active Member

    175
    Oct 11, 2009
    Saugatuck MI / Cape Coral FL
    340 Sundancer 2004 /
    240 Sundeck 2007 /
    10' Zodiac
    Twin 8.1 merc,. V-Drive /
    5.0 merc., bravo 3
    [​IMG]




    [​IMG] [​IMG] Bronze Strut for Sea Ray 320 Sundancer and others 1603547




    Our Price: $2,113.90

    Product Code: 25564-STRUT

    I see this one on Flounder Pounder
     
    Tacoma290 likes this.
  6. Tacoma290

    Tacoma290 Active Member SILVER Sponsor

    194
    Oct 5, 2006
    Tacoma, WA
    340 Sundancer 2007
    Twin 8.1S V-drives

    Up for Sale:
    290 Sundancer 2000
    Twin 5.0L EFI Bravo Drives
    Update: Strut is on the way. As long as I am waiting for it, and the port side exhaust was disassembled to access the strut fasteners, I decided to change the impellers on both engines. At least that item will be off the list in the spring.
     
    Chris-380 likes this.
  7. Chillaxin'

    Chillaxin' New Member

    2
    Nov 23, 2019
    Tacoma, Wa
    300 Sundancer 2002
    383 MAG Stroker w/Bravo III
    It's amazing how much debris is in our waters. Some like to show up well in the water, some like to lurk just beneath the surface. Add some windchop... I've had to do some hard-overs to avoid the stuff. Resulted in the pax spilling some red wine. Better to clean that up than deal with busted outdrives.

    Congrats on the purchase!
     
  8. Mike sandor

    Mike sandor Active Member GOLD Sponsor

    152
    Jul 28, 2017
    Eau Claire, Wisconsin
    2007 320 Sundancer
    Twin 496. Bravo 3
    2018 3500 Chevy, Loadmaster trailer
    Raymarine Axiom, Quantum 2
    496 Mercruiser/Bravo III drives
    I am fortunate enough to have a machine shop so I would be looking at options for repair. Sounds like you have a solution at hand but I would think this could be be set up on a mill and re bore back to center then bush back to original bore dimensions. Need to have enough wall thickness for this to work but at the cost for a new one, may be worth a look. Could also machine one from a billet of bronze. That would be a fun job. Three more years and I am retiring, looking forward to more time in the machine shop!!
     
  9. Tacoma290

    Tacoma290 Active Member SILVER Sponsor

    194
    Oct 5, 2006
    Tacoma, WA
    340 Sundancer 2007
    Twin 8.1S V-drives

    Up for Sale:
    290 Sundancer 2000
    Twin 5.0L EFI Bravo Drives
    Thanks Mike for the great explanation of how it is done. I need to make more friends with Machinists!
    The previous owner had two separate run-ins with logs, and there was some surface pitting on the strut. So the word that our local prop machine shop said was that repair of the strut 'it is not advisable.' I suppose I could have talked them into it, but I have learned that when you ask the opinion of an expert, you should listen to it.
     
    Mike sandor likes this.
  10. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Cobalt CM23
    GM SB 383" Stroker" Alpha Gen I
    You mentioned Sea Trial but not survey, Was it surveyed? A reputable marine surveyor should have see the misalignment in the shaft at the cutlass bearing.
     
  11. Tacoma290

    Tacoma290 Active Member SILVER Sponsor

    194
    Oct 5, 2006
    Tacoma, WA
    340 Sundancer 2007
    Twin 8.1S V-drives

    Up for Sale:
    290 Sundancer 2000
    Twin 5.0L EFI Bravo Drives
    Yes it was surveyed. I would have hoped it would have been caught at that time too. But I don't know whether that is fair to the surveyor: If I guess that the distance from the strut to the shaft log is about 36 inches and the misalignment is 0.75 inches, then it is 1.2 degrees off. This may not be visible to the naked eye.
    How is the alignment of the strut compared to the shaft log normally verified by reputable surveyors? I ask this because I don't know since my last few boats have been IO not v-drive.
     
  12. techmitch

    techmitch Well-Known Member GOLD Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    I'd say, a known perfect shaft would be your best alignment tool short of a laser set up.
     
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  13. Tacoma290

    Tacoma290 Active Member SILVER Sponsor

    194
    Oct 5, 2006
    Tacoma, WA
    340 Sundancer 2007
    Twin 8.1S V-drives

    Up for Sale:
    290 Sundancer 2000
    Twin 5.0L EFI Bravo Drives
    Update: The new strut is on, and the boat was splashed back in the water yesterday. As goofy as it sounds, the new strut required a washer shim to align the shaft to the shaft log opening in the hull. Then, the transmission and engine needed to be re-aligned.
    We checked for leaks after splashing; No leaks. Fired up the engines (I used dishsoap to lube the new impellers and it takes forever for the water to start exiting the boat; Never so relieved to see suds in my life!). Check for leaks at the shaft seal after putting the boat in gear at the dock; No leaks. Left the yard and cruised home on a nice strong plane. Checked for leaks after I docked (another solo docking); No leaks.
    We will re-check alignment after the boats been in the water for a few days.
    I'll post a photo of the old strut next week. I can see why it could not be saved.
     

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