Cat 3406 ID help

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Cdubb, Mar 7, 2021.

  1. Cdubb

    Cdubb Light Load Member

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    I drive a 1994 KW T800, it has a 3406 in it but I’m not sure which series it is. Casting on the head reads 018402 and 3K04. There was no tag on the valve covers as I have read about elsewhere. Are these the numbers needed to ID it? If so what is it? I think it’s a C but it could be a B too I suppose. B5E0D149-9DD4-4F27-A4B1-7FB33E6DB470.jpeg
     
    cke Thanks this.
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  3. bjrc

    bjrc Light Load Member

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    The needed number is stamped on the rh side of the engine block, pass side.
     
  4. AModelCat

    AModelCat Road Train Member

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    I've seen them stamped mid-block on the driver's side as well.
     
  5. Stray_Dog

    Stray_Dog Bobtail Member

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    The serial number around that year won't always confirm if it's a C or B. Cat had alot of mixed up information on serial numbers around the 3ZJ prefix Era. 93ish. To know for sure,, its best to pull the pan and verify which crankshaft you actually have. A couple ways that might help get you closer to determining if its a B or C,

    Look at the pump. Is it a 7E-5888 pump or 7W-3906?

    Also, does it have the big square port exhaust manifold or is it a round port that reassembles a 3406E or C15?
     
    Cdubb Thanks this.
  6. Cdubb

    Cdubb Light Load Member

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    Thanks for the advice, I’m looking for something a little less invasive to confirm it if possible. As you said dropping the oil pan is the guaranteed way to tell but something less involved would be better. I’m no mechanic so I’ll post a pic of the manifold maybe you guys can get a better idea with a wider angle photo. It’s a company truck that I run everyday and I’ll have the first shot at buying when my boss upgrades the fleet this summer. He doesn’t know much about it other than it’s been around forever so I’m trying to do the detective work and see what’s what on the old gal.
     
  7. Cdubb

    Cdubb Light Load Member

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    There a certain amount of numbers or a suffix I should be looking for to know I found the number?
     
  8. Dino soar

    Dino soar Road Train Member

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    If you call the dealer with the VIN number can't they tell you the exact model of the engine?
     
  9. dirthaller

    dirthaller Heavy Load Member

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    In the door jam it might have a tag somewhere that says “3406peec” or 3406atac” if it’s the later, it’s a 3ZJ engine the peec engine has an 8PN serial number..........unless the engine has been swapped.
     
    Cdubb Thanks this.
  10. dirthaller

    dirthaller Heavy Load Member

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    B engine has 6 point head bolts C engine has 12 point bolts. They never put a b in a 1994 truck from the factory. I’ve talked to multiple people who claim that they have a B under their hood and in almost every instance, I lift the hood to find a C. B’s were obsolete by 1994.
     
  11. Stray_Dog

    Stray_Dog Bobtail Member

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    Im aware of the head bolts. Good catch.

    The 3ZJ could have been a B or C though. When Cat transferred alot of part numbers over to the new system in the early 90s, they had alot mixed up info on serial numbers. Thats why I asked which manifold or pump it had. Not only that, but that engine could be a transplant.
     
    Last edited: Mar 9, 2021
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