1991 Force 50hp

Discussion in 'Bubba's Outboards' started by 1sporticus, Feb 21, 2007.

  1. 1sporticus

    1sporticus Active Member

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    Iowa
    Hi guys, I have a friend who has a 1991 Force 50 hp, that is giving him fits. The lower unit seems to wear out his forward gear on a yearly basis. He replaces the pinion, and the forward gear each time, and last year he had the bushing in the lower unit changed plus new gears. Have you got any ideas. Later Andy
     
  2. Bobpaul

    Bobpaul New Member

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    Can't say exactly, but if the lower unit gears aren't shimmed to operating tolerances, meaning proper contact and lash, they'll wear out.

    Each lower unit is machined slightly different and bearings, bushings,and races, fit slightly different, causing the need to shim the gears.
     

  3. 1sporticus

    1sporticus Active Member

    Messages:
    1,006
    State:
    Iowa
    Thanks Bob-paul, I had the same thought. I did ask him about that, he had the gears changed 2 years in a row, and last year he did it himself. He claims he did lap the gears, and they looked good to him. What you should know about him is that he's a mechanic, he was a crew chief on an ASA class car, and now he runs an auto repair shop, so he is familiar with gear lapping ect. He is scratching his head, and can't seem to be able to figure out what is going on. I had thought that the drive shaft may be bent or something, or possibly the bearing in the top of the drive shaft going bad. I don't know at this point, but it is bound to be something oddball. Hope you can help. Later Andy
     
  4. Bobpaul

    Bobpaul New Member

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    I wonder what the manual says to look for? I don't have one on that engine