Timing chain broke on start up. Need advice.

Discussion in 'Engine/Drivetrain' started by Christopher Sutton, Dec 18, 2016.

  1. Christopher Sutton

    Christopher Sutton Member

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    Just rebuilt an 87 22r engine. .20 over pistons, .10 over bearings, new timing chain set, timing cover, water pump, oil pump, brand new assembled head, LCE cam adjuster, all that jazz. 115 miles after the rebuild (timing is dead on btw) I go to adjust my valves again because they were ticking too loose. (someone told me factory specs while hot). I adjusted the valves cold and checked everything out. I put everything back together, turn the truck over, and I hear a loud metallic pop and snap. The mech fuel pump arm broke AND my damn timing chain broke!! I need to know would you think my valves are damaged? Finances are pretty low and I can barely afford a 2nd new chain.
     
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  2. 22R88

    22R88 Veteran

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    Bottom gear for chain installed facing wrong direction
     
  3. Christopher Sutton

    Christopher Sutton Member

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    I checked that upon assembly. I also have a picture of my timing on previous post.
     
  4. salabim

    salabim Newbie

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    if it ran well for 115 miles. Now wont after a valve adjustment you have the answer. The work last done on the engine is the problem.
    I would say its time to pull the head again. Will the cam turn through two revolutions with the chain off? How about the crank?
     
  5. Christopher Sutton

    Christopher Sutton Member

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    I haven't tried because I didn't want to purposely damage my valves trying to turn it. I wonder if the chain had too much slack on the driver side when aligning TDC. Does that sound stupid?
     
  6. salabim

    salabim Newbie

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    Chris,

    Something has to have jammed the cam to break that timing chain. Whether its slack valve timing or something else. I have no idea what the tensile strength of the chain would be. I could guess and say 3000 lbs.
    Pulling the head is gonna tell ya right away if its a valve that has introduced itself to the top of a piston. No matter what the cause it needs to come off.
     
  7. Christopher Sutton

    Christopher Sutton Member

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    Okie dokie. Like I mentioned earlier, the fuel pump arm is missing as well. That might have gotten jammed in there.
     
  8. first80toyota

    first80toyota Addict

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    Seeing as the starter engages the flywheel which attaches to the crank, in order to snap the chain it has to be something on the upper side. Could be the tensioner some how jammed the chain, or cam, or the fuel pump rod or any combo of things.

    Any way you go, start digging and you will find it! :waytogo:
     
  9. Christopher Sutton

    Christopher Sutton Member

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    I guess I will tear it all apart after Christmas. Too much going on and all I can think about it this truck.
     
  10. tacobo670

    tacobo670 Addict

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    i would suspect the valves would bend/brake before the chain would snap. then again, idk what kind of cheap-o chinese taiwan chain u got.
    is it possible the ACG is loose when u was adjusting the valves?
    did u notice the fuel pump arm broke BEFORE or AFTER the chain snap? maybe the arm had broke and then managed to wedge itself into the chain not allowing it to turn and therefore breaking it?

    regardless, best bet would be to pull the head and timing set n see how bad the damage is. sucks bro
     

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