Crank shaft / Alum smear

Discussion in 'Mechanic and Repair' started by tal320, Sep 27, 2006.

  1. tal320

    tal320 LawnSite Member
    Posts: 9

    Kohler twin 18 hp with bottom pulled off. Broken comnnecting rod left smeared aluminum on crank bearing surface. Trying to remove alum. without removing crank. Im told of an acid that will remove the aluminum and not harm the crank.

    Any help is appreciated.
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Use a long strip of fine Emery paper about a inch wide to remove and buff clean. Then flush the engine block with a cleaning solvent.
     
  3. General Landscaping

    General Landscaping LawnSite Senior Member
    Posts: 802

    I'd keep looking for more info online, but it seems like muratic acid is what you are looking for..... pool supply store or Home Cheapo.

    I know emery cloth is the usual way to do it; but it seems like that would remove some material from an already worn rod journal:confused:
     
  4. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    the last thing i would do is use any acid on a engine when 2 minutes with some emery paper like Retrorob posted would do the trick. you would spend days on the journal before you would begin to undersize it.
     
  5. Jim@MilkyWay

    Jim@MilkyWay LawnSite Senior Member
    Posts: 472

    Correct me if I'm bad, but aren't cranks made of hardened steel?
    Not only will emery be so "slow" at material removal as to be _totally_ negligible, on the journal, but it will also de-glaze the surface and allow better break in of new bearing.
     
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023


    Yes they are Jim, Thats why it's best to use emery cloth to remove the softer aluminum quite quickly and not have to worry about under sizing the journal.
     
  7. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    restrorob and jim have it right. no need to reinvent the wheel.
     
  8. tal320

    tal320 LawnSite Member
    Posts: 9

    It works. Spun rod left 2-mills of alum smeared on the crank. Muratic acid and a eye dropper is the key Took about an hour to drip alum off with crank in place, however I took the second rod off to find more and so the whole crank had to come out in the end so i could polish the bearing surfaces.

    Now i need connecting rods. Everyone says they have to special order. Who keeps parts in stock for a kohler 18hp cv18s twin?
     
  9. khouse

    khouse LawnSite Bronze Member
    Posts: 1,465

    what did you use to polish the journals?
     
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Man, 15 maybe 20 tops with Emory paper.....

    Check here for parts; http://tulsaenginewarehouse.lookupparts.com/parts.asp
     

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