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Replace Crank bearing?

Discussion in '40- & 55-Series Tech' started by atoyot, Feb 22, 2004.

  1. atoyot

    atoyot

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    My engine (73' F) was knocking so I narrowed it down to the crank shaft. I dropped the oil pan and found the #6 bearing to be loose. Sure enough the bearing was all jacked up. It wasn't to bad. But the shaft has some slight grooves in it from the rubbing. Can I just replace the bearing or do I have to get the shaft machined smooth? By the way oil pressure is good and oil level is good. If I can just replace the bearing can I do it with the engine installed?
     
  2. Jesse

    Jesse

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    It all depends on a few things.
    1: How badly worn is it? (measure it with plastiguage)
    2: How much do you drive it?

    If you did not drive it everyday and its not to badly worn you might be able to just replace the bearing. Maybe clean the crank up with some emory cloth etc??
    Good Luck.

    Jesse
     
  3. atoyot

    atoyot

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    plastiguage? What is that? It's a daily driver/trail rig.
     
  4. Steel

    Steel

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  5. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    Has the connecting rod discolored?

    Post some pics...
     
  6. 60wag

    60wag SILVER Star

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    If the crank has very minor damage, you can pollish the surface with some fine grit sand paper. Then compare the repaired surface to the #5 throw with a micrometer. If the two are within 0.002" on diameter, you should be OK. The Toyota book allows for an 0.004" oil clearance, ie the crank can be .004 smaller than the id of the bearing. Nominal is 0.001-0.002. Since the engine has good pressure elsewhere, the odds of a quick fix lasting are good. If it doesn't work for long, you'll just have to tear down the engine some other time so its worth a try.