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  1. #1
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    Left hand rotation question

    How is this done? I've studied the rebuild section for LUs but it didn't show a left hand unit and am mystified about the thrust bearing deal.
    Using the rear or reverse gear leaves no decent thrust bearing location.

    I assume the drive shaft is still turning the same direction and only the LU is needed to reverse rotation?
    '90 STV
    '96 260
    under construction

    for far too long

  2. #2
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    Yes, the driveshaft still turns the same direction, it just uses the reverse gear as forward gear, the bearing layout is different and there is a thrust bearing that works off the middle of the propshaft, I can't describe it very well but if you look at

    www.mercruiserparts.com
    and go to the parts ordering section for outboards you can see the michrofiche(not really michrofiche as it's online) for ordering parts for the counter rotating gearcases and it should be fairly self explanetory.

    Hope this helps,

    Caleb

  3. #3
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    I looked and looked... and don't see it. There is a difference in the layout from standard to counter but nothing between the gears except the clutch stuff. Seems to be extra stuff behind the reverse gear but thats not a forward thrust?
    Is it the prop shaft thats different?
    Rev gear slides onto prop shaft for standard & prop shaft slides into rev gear for counterrotation? Thats all I can come up with, where the ridge is on the shaft.
    '90 STV
    '96 260
    under construction

    for far too long

  4. #4
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    The prop shaft has a flange on it for the thrust load.There is a thrust bearing and a housing in the carrier that takes the thrust loads from the prop shaft.The prop shaft end play is contained by the flange on the shaft, it doesnt ride on the gears like the standards.dave

  5. #5
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    The only counter-rotating units I've had apart are for the 3.0 litre Mercs, the thrust is taken by a couple half rings that go in a groove in the propshaft and then a notched(for the sake of a better description)(Mercury calls this a Thrust race) washer goes on each side of the half rings on the front and the back of the washers goes a thrust bearing, they ride between the bearing carrier and the Bearing adapter assembly.

    Looking at the parts diagram for a 2.5 offshore with a Sportmaster gearcase it looks a little different but the thrust bearings still go between the bearing carrier and the bearing adapter assembly. The flange that H20PERF is talking about must go in the same area.

    Hope this helps,
    Caleb

  6. #6
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    In the bottom of his screen it shows he has an older 260 that would have a cle case.Either way they basically work the same a flange on the shaft with thrust bearings on eachside contain the shaft, its just a matter of how the flange is connected depending on the case.I think merc went to the design like you are talking about on the 3l cases to save on production costs.The flanged shafts have to be made from a piece of stock the O/D size of the flange and the newer design can be done with the std shaft diameter. Dave

  7. #7
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    Thanks all. This makes sense from the diagrams. The gear pushs on a ridge or captive ring on the shaft- then on the thrust bearing.
    '90 STV
    '96 260
    under construction

    for far too long

  8. #8
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    nope!

  9. #9
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    i,m sorry i was mistaken no i was yes i was,nt no thats right
    nope

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