Camshaft end play

Discussion in ''Da Nailhead' started by 66larkgs, Aug 28, 2019.

  1. 66larkgs

    66larkgs paul 66gs turbo nailhead

    seems like my old camshaft Has a ton of end play in it. Any insight or experience on this would be a huge help. Button springs on these? Going to pull the timing Cover An old camshaft out in a little bit. Going to install new camshaft bearings tonight
  2. Bigpig455

    Bigpig455 Fastest of the slow....

    from what I can tell, the cam is held against the rear snap ring by the spring pressure on the lifters. When I had no pushrods in the motor, the cam would walk forward while rotating. When the pusrods and rockers were in, cam stayed put..
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Are we talking flat tappet? Cam lobe taper forces the cam towards the back of the engine. Roller cams use a cam bumper. How about the rear cam plug? Driven in to the correct depth?
  4. 66larkgs

    66larkgs paul 66gs turbo nailhead

    No snap ring back thier.looks like the plug was flush with the back of the block

    Attached Files:

  5. gsgtx

    gsgtx Silver Level contributor

    the cam will never hit the plug, the timing gear hits the front of the block first
    cray1801 and Lucy Fair like this.
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Is it possible that it did exactly that and wore the front of the block?
  7. Wildcat GS

    Wildcat GS Wildcat GS

    Pretty sure there should be a snap ring in the back of the block....
  8. 66larkgs

    66larkgs paul 66gs turbo nailhead

    That is the back of the block. Looked like at some point flywheel was hitting
  9. 66larkgs

    66larkgs paul 66gs turbo nailhead

    The timing gear hits the block as gsgtx said and does not hit the plug
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    OK, what I am saying is maybe the front of the block is worn from contact and that’s the reason for the excessive end play? Don’t know that much about Nailheads but have seen that on the SBB.
  11. telriv

    telriv Well-Known Member

    The rear of the cam runs against the rear snap ring. I have seen them put in backwards from the factory. The rounded portion goes TOWARDS the camshaft. The flat portion goes to the rear of the block towards the rear cam plug. IF installed backwards the cam tries to force the snap ring out of the groove. I've seen it a couple of times now.
    300sbb_overkill likes this.
  12. GranSportSedan

    GranSportSedan Puppet dictator, wife has all power

    Well that's part of your problem. There is supposed to be a snap ring back there.
  13. Buford

    Buford Old guy member

  14. telriv

    telriv Well-Known Member

    AND ANOTHER, "LETS DO THIS AGAIN". You are correct about the dist/oil pump & as Bigpig455 says the lifters & springs force the cam to the rear.

    What did the original ALUMINUM cam gear do??? It would have started to wear the 1st. time the engine was started. DO YOU THINK THE FACTORY OR THE ENGINEERS WOULD HAVE ALLOWED THIS????

    IF I remember correctly ALL "Nails" had the snap ring in the rear of the block. I'M POSITIVE ABOUT THIS ESPECIALLY FOR THE
    364/401/425 & as gsgts has ALSO said.

    ALSO the snap ring has a proper & an improper way to be installed. IF the snap ring has a slight curve in it that curve goes towards the BACK OF THE CAM!!!! The flat side towards the rear of the block.. If the snap ring is flat on both sides it can go in either way.

    I've had a couple 401/425's that had this snap ring installed backwards from the factory & the snap ring was trying to climb out of the back of the block.


    Understand this Paul. IF you don't believe me call Russ at Centerville. The snap ring is easily acquired by going to your local hardware store & getting one. OR, if you'd like I have them in stock.

    Tom T.
  15. GranSportSedan

    GranSportSedan Puppet dictator, wife has all power

    I had a 401 in my 65 GS that was rebuilt by a professional shop in California for the original owner, forged pistons an the whole works. I thought it had a horrendous rear main seal leak so I pulled it out to clean it up and re gasket. I found that the shop never put the plug in the cam journal at the back of the engine but the snap ring was there. After I put that plug in it never leaked a drop.

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