Need timing help, keep breaking pushrods, CAT 3406

Discussion in 'Trucks [ Eighteen Wheelers ]' started by zx150, Jun 15, 2012.

  1. zx150

    zx150 Medium Load Member

    343
    45
    Mar 30, 2012
    0
    Will take a look and report back with photos. Thanks again!
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. zx150

    zx150 Medium Load Member

    343
    45
    Mar 30, 2012
    0
    Front cover is off and this is what there is to see. There is the letter 'K' engraved into the cam gear(visible near 03:00) but that is the only mark that I can really make out. The engine is set at #1TDC in these photos:

    [​IMG]

    [​IMG]

    [​IMG]

    I read and reread the manual that I have for this motor and it says nothing about timing the gear train.
     
  4. Heavyd

    Heavyd Road Train Member

    7,752
    6,186
    Feb 4, 2009
    0
    Hate to tell you, but you need to pull everything apart now. You probably have bent valves and damaged pistons. Always always always bar the engine over by hand before you crank it.
     
  5. Gear head

    Gear head Medium Load Member

    532
    91
    Apr 1, 2012
    Belair,md
    0
    There should be dots on crank gear and cam gear at teeth
     
  6. zx150

    zx150 Medium Load Member

    343
    45
    Mar 30, 2012
    0
    That's exactly what I was doing. I spun the motor over by hand with a bar checking for interference and found it. I learned that lesson the hard way many years ago with an old Jeep, now I guess I know why.
     
  7. zx150

    zx150 Medium Load Member

    343
    45
    Mar 30, 2012
    0
    No dots on the crank or idler gears which is what has me confused.
     
  8. zx150

    zx150 Medium Load Member

    343
    45
    Mar 30, 2012
    0
    Just got off the phone with the CAT technical service adviser and this is what I'm told:

    Normally there are "V" marks on the crank gear and large idler gear as well as two "K" marks on the cam gear. The "V" on the crank gear sits at 12:00 while the "V" on the large idler gear sits at 06:00 and the two "K" marks on the cam gear sit at about 11:00 and 07:00 or just barely outside the outer edges of the large idler gear.

    I'm going to go try this and see what happens. I posted the technique in hopes that it will help somebody else out down the road who's having the same issues. I'll try and get a photo posted once it's done correctly.

    Thanks again for all the help guys!
     
  9. zx150

    zx150 Medium Load Member

    343
    45
    Mar 30, 2012
    0
    Here's the finished product:

    [​IMG]

    If you look close you can see the "K" marks on the cam gear. Turns out there were "V" marks on the idler gear and crank gear but they were covered over with several layers of old paint and grease pen.
     
  10. Gear head

    Gear head Medium Load Member

    532
    91
    Apr 1, 2012
    Belair,md
    0
    The center is a cluster gear. What model of 3406 is this b c a? It looks like that line on cam gear is supposed to line up with v on cluster gear. What about fuel pump timing since things got out of whack?
     
    Last edited: Jun 15, 2012
  11. zx150

    zx150 Medium Load Member

    343
    45
    Mar 30, 2012
    0
    It's supposed to be a B or C but we're not sure, there's no identifying marks on the block like a serial #. The serial # KW gave us comes back to a C but CAT says that same number comes back to a B so who really knows. I ended up going thru it again after I took the photo and got it lined up better. Fuel pump timing is next, should be easy with the timing pin. I guess we'll see.
     
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.