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Thread: Ironhead woes.

  1. #1
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    Default Ironhead woes.

    so my 1979 ironhead has been making some of the most god-aweful knocking sounds for a while now, I'm not sure what caused it.

    after much dicking around with the top end, I finally took the timing cover off. and discovered that all the shims for the front intake cam were smushed and mangled.

    Would this cause a loud metal on metal noise?

    Also, where can I find shims, and how does one shim the timing on a 1979 ironhead sporty?

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    You got some work to do it sounds like, first the shims must of got hot on the timming side and they bound up enough to cut them up and then they ran though the gears, in which probley got in to you bottom end thouth the oil system. you may have a bad crank bearing or a bottom riss pin bearing out. that would cause some slack in which causes it to hop and clunk. I also could be a bad cam gear and is causing a push rod to be out of ajustment, you will only know by opening it up. but metel getting into your oil is not good, change your oil and look in it for metal flakes. good luck

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    by 'smushed and mangled' I mean the shims were pressed and distorted in size, shape and thickness. They were, however, still in one piece.

    the oil's clean, no magnetic flake in it ( the usual pinch of aluminium, but nothing significant ).

    but the shims were pushed up past the shoulder, and no longer shimming the cam.

    which leads me to the question again 'if those shims are pushed up, or missing, would it make a lot of noise?'

    I"m trying to figure out how much further I want to get into this motor. I've been chasing this noise for 3 months, and If this is it, I want to be Done With It.

    starting to hate this bike.

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    a 'loose' cam can make a slight knocking noise, does the noise get louder with RPM's? can u take a video of the noise? "knocking" can mean alot of different things to different people, primary chain tension correct?

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    Quote Originally Posted by Roguetek View Post
    by 'smushed and mangled' I mean the shims were pressed and distorted in size, shape and thickness. They were, however, still in one piece.

    the oil's clean, no magnetic flake in it ( the usual pinch of aluminium, but nothing significant ).

    but the shims were pushed up past the shoulder, and no longer shimming the cam.

    which leads me to the question again 'if those shims are pushed up, or missing, would it make a lot of noise?'

    I"m trying to figure out how much further I want to get into this motor. I've been chasing this noise for 3 months, and If this is it, I want to be Done With It.

    starting to hate this bike.
    Don't hate. Tear it apart and figure it out my man. Finally got my tuned great, and will now never get rid of mine. Yes, if the shim is not in place, it will cause the cam to flop around a little, and can make noise. It could have also messed up the tappet depending on long it was ran that way. Tappets on these things sound awful when going out. Without hearing it ourselves, it is hard to say for sure if that is it. A huge help would be to get a mechanics stethoscope. If you have a manual, and a understanding of what is going on inside the motor, the stethoscope will help you pin point exactly where the noise is coming from. Like right behind the cam cover, vs. inside the crank case. Ironhead303's was making an awful clunk. I think he swapped a cam and a tappet to fix it, but then it happened again and was a faulty pressed crank out of the box from S&S. I am not trying to scare you, chances are it's just that shim if everything else was running good. Either way you need to re-shim the cam (it's in the manual too, kinda a long to write out here) and if it still makes it, your out a cam cover gasket (about $10) when you have to take it back apart. Know what I mean? Either way you gotta get that cam in there right, so start there. Good luck my man, stick to it, you'll figure it out. Besides, that is half the fun!

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    Sounds like your chain tensioner could need to be adjusted on your left side of the bike if you havent done it recently or ever. It adjust the chain between your crank and the clutch. If it gets loose it will slap the case inside making a loud banging noise. This is one of the most common noises loud banging. If it has been going on a while. Other times you hear loud banging it usually is followed by boom sooner then later.

    Last edited by atomrotten; 10-16-2010 at 8:59 PM.

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    chain tensioner has already been replaced, about 150 miles ago, and tension was checked prior to pulliing the timing cover off.

    Cant start it and run it, because the front head is off, and the timing cover is off, and I dont have any shims that arent mangled.

    So I'm going to get some shims, shim it correctly, put the head back on, and have a listen.

    I did use a stethescope on the engine, and it told me that the sound was coming from the front head. Which does not seem to be the case, as the rockerboxes have been freshly redone, and the endplay in the lifters and the lifterblocks is within tolerance.

    I'm hoping that the solution is not going to involve splitting the cases, I want to get this thing sold, so I can put my cash into the 80 shovel I'm buying.

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    Rocker box could be worn out and that is a easy fix in my opinion compared to my noise ending in a bad lower end bearing.
    Im drinking a double shot to your luck of it being the rocker box!

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    also keep in mind that all ironheads have noisey valve trains, they are a solid lifter so it will make some noise. also even if you chain is ajusted it could be the chain has lots of slack and still will bang around. I have a 1980 and it makes tons of nosie. but everthing is good. put it together and sell it get the that shovel on the road. gotme a 72 shovel that is just as loud.

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