I overtorqued my connecting rods

Discussion in 'Mechanic and Repair' started by Camaro865, Dec 31, 2011.

  1. Camaro865

    Camaro865 LawnSite Member
    Posts: 52

    i'm in the middle of freshening up a kawasaki fh500v engine and i took the connecting rod caps off to inspect them. long story short putting it back together they got torqued down to 8 or 9 ft pounds, book is 52 inch pounds, so just over 4 ft pounds.

    the rods are aluminum, would it be safe to just take the bolts out and re torque or would i be better off with new rods? besides this they are perfect with no wear. i dont know if i'm being too critical with this or not, i just dont want to have any problems down the road.

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  2. unkownfl

    unkownfl LawnSite Gold Member
    Posts: 3,838

    Get new bolts or studs
     
  3. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    Replace the rods.
    If they come loose there won't be anything to rebuild.
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  4. BigFish

    BigFish LawnSite Gold Member
    Posts: 3,165

    I wouldn't replace the rods, what for?? Just get some new bolts ( ya really don't need to tho) ****** the threads in the rod and bolts with some carb cleaner/contact cleaner and use a drop of RED locktite on the bolt threads and a drop of oil under the bolt heads.
     
  5. Patriot Services

    Patriot Services LawnSite Fanatic
    Posts: 12,695

    IMO I think you'll be fine. I would check clearence with old school plastigage at the factory torque setting to make sure the bolts didn't stretch or distort the threads. Red locktite will keep them from loosening.
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  6. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    My concern is that the aluminum threads were torqued over twice the recommended torque.
    If the threads pull loose, all the locktite on the bench won't stop the bolts from coming out.
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  7. jsslawncare

    jsslawncare LawnSite Bronze Member
    Posts: 1,674

    I'm an engine machinist that turned full time grass cutter, REPLACE THE RODS! You doubled the torqe spec. You can't recon the small engine rod like you can a auto rod. The big end will be out of round. But, the rods are too cheap for what it would cost if the motor were to sling a rod. REPLACE THEM and make sure you put the caps on in the right direction.
     
  8. unkownfl

    unkownfl LawnSite Gold Member
    Posts: 3,838

    BTW you shouldn't be using that big of a torque wrench.
     
  9. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    x3............
     
  10. Patriot Services

    Patriot Services LawnSite Fanatic
    Posts: 12,695

    The more I think about it changing the rods would be your safest bet. Your already tore down this far. Guaranteed if they failed it would be when you need the mower most. Plus failure will window the block for sure.
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