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Camshaft housing question

Discussion in 'Gen 3 Prius Technical Discussion' started by Ben Je, Mar 13, 2021.

  1. Ben Je

    Ben Je Junior Member

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    I am reassembling my 2012 Prius V after a HG replacement. When installing the camshaft housing, will it sit flush on the CH prior to tightening the bolts or do you have to suck it down (other than squishing the gasket material)? I set it on top of the CH but it never would set down fully. I suspect a rocker arm may have moved out of position but was just checking. Prior to disassembly I positioned the camshafts correctly with the yellow links and locked them in position with the paper towel trick.

    Thanks!
     
  2. tre4xw30

    tre4xw30 Junior Member

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    Don't use acronyms if you want help.

    SM-N986U1 ?
     
  3. ChapmanF

    ChapmanF Senior Member

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    From context, I am guessing HG is head gasket and CH is cylinder head. It might be a little risky to use CH in a post titled "camshaft housing", but then the camshaft housing doesn't sit on itself, so the meaning gets sorted out.

    Even with all of the rockers correctly positioned, the cam housing will probably not rest flat on the cylinder head without being cinched down. No matter where you are in the cycle, some valves in some cylinders are going to be open, that is, pushed down against their valve springs. Essentially, as you cinch the cam housing down, you are opening whichever valves are s'posed to be open at that position.

    Are you following the Repair Manual (more info)?
     
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  4. Ben Je

    Ben Je Junior Member

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    Thank you for the reply and sorry about the acronyms.

    I'm using the repair manual (I've downloaded the attachments) as well as YouTube videos. But since this is my first Toyota head gasket repair, I'm in unfamiliar waters. Everything had gone well until the camshaft housing part. Part of me wanted to take it off and inspect what the difficulty was, but I thought what a mess with the gasket maker (Permatex Ultrablack) I also had another difficulty with it that I didn't mention in the first post.

    I was tightening up a rear camshaft housing to cylinder head bolt and either the bolt was weak, my torque wrench (harbor freight) is not working correctly, or I'm a lot stronger than I think. The bolt snapped in the cylinder head. So now I'll have to take the head off and take it to a machine shop Monday. I just wasn't being as careful as I should have been. Or using my head.

    It may have been that I moved a rocker out of position putting the camshaft housing in place and that was the reason it didn't set down easier. I didn't check that before I started tightening the bolts. When I lifted the housing off one was out of place but I don't know when it was moved. I'll check that next time.
     
  5. Ben Je

    Ben Je Junior Member

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    Here’s the broken bolt...
    0D36A8C1-C9DD-4032-B762-8A0C8FEEB9AB.jpeg
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    No clue, but I can manage to decipher CH without breaking a sweat, and others more in the know likely will too.
     
  7. The Critic

    The Critic Resident Critic

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    Do you have a set of left-hand drill bits? That bolt should drill out fairly easily.

    There is a sequence to torquing the cam housing/carrier and it should be followed (for this reason).
     
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  8. ChapmanF

    ChapmanF Senior Member

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    That looks as if it might be projecting a little. If you are able to glom onto it with locking pliers, it might spin right out.
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    I’m probably missing something fundamental, but I see three blackish socket head cap screw heads that I think are head bolts, and they all look intact. I must be missing something lol.
     
  10. ChapmanF

    ChapmanF Senior Member

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    Direct your gaze slightly upward from the middle intact blackish head bolt, to admire the twisted carcass of a former camshaft housing bolt above it.
     
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