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Thread: Cat d4 7u smoking and popping louder now

  1. #21
    Join Date
    Nov 2006
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    Faunsdale, AL USA
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    4,163

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    You should find two marks on flywheel 180* apart
    Cylinder pairs are 1&4and 2&3 stamped next to the marks As you have probably gathered from the instructions so far, when a mark is aligned with the pointer in the window, one of the cylinders listed will be at TDC of compression stroke (where fuel is being injected for ignition) with both valves closed and rocker arms loose.

    The other one is at TDC between exhaust stroke and intake stroke with valves rocking, so rocker arms are tight To use the OldMagnets method, just make sure you are starting with the correct cylinder on compression stroke.

    Oh, occasionally the question arises, so cylinder #1 is next to radiator.

    A piece of chalk or brightly colored crayon would be nice to have to highlight the marks.
    Last edited by ccjersey; 01-21-2020 at 08:00 PM.
    D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time

  2. #22
    Join Date
    Dec 2019
    Location
    Columbus, ms 39701
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    44

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    Quote Originally Posted by ccjersey View Post
    You should find two marks on flywheel 180* apart
    Cylinder pairs are 1&4and 2&3 stamped next to the marks As you have probably gathered from the instructions so far, when a mark is aligned with the pointer in the window, one of the cylinders listed will be at TDC of compression stroke (where fuel is being injected for ignition) with both valves closed and rocker arms loose.

    The other one is at TDC between exhaust stroke and intake stroke with valves rocking, so rocker arms are tight To use the OldMagnets method, just make sure you are starting with the correct cylinder on compression stroke.

    Oh, occasionally the question arises, so cylinder #1 is next to radiator.

    A piece of chalk or brightly colored crayon would be nice to have to highlight the marks.
    Great! Thanks for the advice and clarification on everything. I'm new at doing this type of adjustment but sounds like it's very doable so we shall see

  3. #23
    Join Date
    Nov 2006
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    Faunsdale, AL USA
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    Quote Originally Posted by dpendzic View Post
    are all the 4 cyl engines the same--d311, 3204,3304, etc?
    Pretty much.
    I think one of the real old gas Caterpillars was not 1342 firing order, but everything else I’ve ever run into (of any brand) has been. I think it must make a stronger crankshaft or some other good reason for it to be pretty much universal.

    The two position method of adjusting valves works because the camshaft lobes have more than half their rotation where the lifter is on the base circle. Since the camshaft turns at half the speed of the crankshaft, this means that you have most of a whole revolution of the engine where the valves are closed (lifter/tappet is on base circle of camshaft) and can be adjusted.
    D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time

  4. #24
    Join Date
    Sep 2016
    Location
    nebraska panhandle
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    82

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    My 52 D4 7U has the exact same problem on the same cyl. as you describe. I'm going to adjust the valves and do it with the engine running. Let it get to normal temp then put the throttle at low idle and adjust the valves. When I was a young man growing up I would watch mechanics set the valves on those 6 cyl. Chevy cars and pickups. They set them running and had good success. I have a neighbor who is going to run the feeler gauge while I do the adjusting. Only have eight valves.

  5. #25
    Join Date
    Dec 2019
    Location
    Pouce Coupe, BC Canada
    Posts
    60

    Default Hydraulic or Solid Lifter?

    Quote Originally Posted by bplunk View Post
    My 52 D4 7U has the exact same problem on the same cyl. as you describe. I'm going to adjust the valves and do it with the engine running. Let it get to normal temp then put the throttle at low idle and adjust the valves. When I was a young man growing up I would watch mechanics set the valves on those 6 cyl. Chevy cars and pickups. They set them running and had good success. I have a neighbor who is going to run the feeler gauge while I do the adjusting. Only have eight valves.
    -are those lifters hydraulic? or solid?

    -you can set the hydraulic with engine idling...not sure with solid...or why there would be an advantage if even possible...
    Caterpillar D6C 99J

  6. #26
    Join Date
    Sep 2016
    Location
    nebraska panhandle
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    82

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    I have the Cat operation and maintenance manual, Form12244-11 and on page 72-73 it gives the adjusting procedure and I read it as engine running OR stopped. Advantage I think is not turning engine by hand for each valve?????? Maybe someone else will chime in and give some thought.

  7. #27
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    Sep 2016
    Location
    nebraska panhandle
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    The Caterpillar Servicemen's Reference Book,Form FOE30522-02 page 175 has a picture of the lifter and it is a solid lifter.

  8. #28
    Join Date
    Nov 2006
    Location
    Minnesota
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    503

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    Takes an experienced hand to feel the slop in a valve while running. Much harder to do accurately while running.

  9. #29
    Join Date
    Nov 2006
    Location
    Faunsdale, AL USA
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    One thing to watch out for is rocker arms that have some wear where it contacts the valve. When everything is nice and flat, the gauge will have a smooth drag with the engine stopped but you may have a little excess lash when you’re done. With it running, your gauge can get chewed up when it gets across a step worn in the rocker pad. Mine still has the marks from my D318 power unit! Not sure how common that kind of wear is on other engines.

    If you think about it, with the engine running, first there has to be enough clearance to get the gauge in in the space. If valve is tightened so there’s no lash, the gauge will bind and stop moving. As you loosen, the gauge will start moving again but will bind every time the valve opens so it’ll feel different than the too tight setting, but not so much different from too loose. To be accurate you have to go from too tight to slightly loose and back again so you find the “edge” where you need to tighten it down.

    I hate working on the adjusters while they’re jumping up and down, so I don’t do it that way any more.
    D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time

  10. #30
    Join Date
    Dec 2006
    Location
    victoria australia
    Posts
    3,172

    Default Narrow Feeler Gauge

    Hi Team,
    as CCJ says, the rocker arm valve stem contact face gets a pocket worn into its curved face.
    You need to grind your feeler blade so it is narrower than the valve stem diameter plus a bit more to allow for the usual chamfer machined at the stem end.

    With badly pocketed rocker arm faces they need to have their surface trued flat with the needed curve to follow the rocker operating radius to help the stem and rocker slide over each other and not cause the excessive side thrust that causes valve to stem wear.

    I have ground them on the side of a fine grinding wheel by hand, with no guide and, a very steady hand and good eye with good results when being el cheapo and/or in a hurry--any engine shop should have the needed attachment to do the rockers on their valve refacing machine.

    These old girls have solid lifters and I would urge you to do the lash adjustment with the engine stopped for best and consistent results.
    Your experience may vary.

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