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Timing Belt: Aligning my Crank/Cam

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    Timing Belt: Aligning my Crank/Cam

    Hello.

    I am replacing my timing belt and other bits, but I am having a bit of trouble aligning my crankshaft and my camshaft together. The issue is I do not see where the mark should be on the cam shaft sprocket.

    This is how I have the CRANK shaft aligned:



    And this is where I have trouble, the only mark I see around the whole cam shaft sprocket is this little line mark, inside the sprocket(it is underneath the sprocket teeth). So the issue is that it does not align with the cylinder head mark at all, when the Crank is aligned :



    ^^^ it is the little line mark, right where the timing belt begins to wrap around the sprocket. There are no other marks on the cam shaft sprocket that I can see to align with the cylinder head line.

    And the following is just an image of the cylinder head line mark to make sure I have it correct:



    So the issue is that I can not seem to line up the cam shaft sprocket. I have rotated the engine around two times to try and get it lined up, but it is still off. I can not see a clearly visible camshaft sprocket line mark, only the little one noted above, which is always off of where it should be anyways.

    #2
    Before you do anything else, get the updated solid cam sprocket (and a new seal and o-ring). The stamped metal sprockets are weak and prone to failure. The new sprocket has a very clear alignment mark on it.

    Don't use the harmonic balance to align the crank. Remove it (you'll have to to change the belt) and you'll find a mark on the crank hub and a v-notch in the inner lower timing cover.
    The car makes it possible, but the driver makes it happen.
    Jim Levie, Huntsville, AL

    Comment


      #3
      Second what he said. ^

      Those gears are weaker early gears and can rust out/ fail. Having said that...

      Early style gear alignment mark:



      Later style gear alignment mark:

      318iS Track Rat :nice: www.drive4corners.com
      '86 325iX 3.1 Stroker Turbo '86 S38B36 325

      No one makes this car anymore. The government won't allow them, normal people won't buy them. So it's up to us: the freaks, the weirdos, the informed. To buy them, to appreciate them, and most importantly, to drive them.

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        #4
        Originally posted by jlevie View Post
        Before you do anything else, get the updated solid cam sprocket (and a new seal and o-ring). The stamped metal sprockets are weak and prone to failure. The new sprocket has a very clear alignment mark on it.

        Don't use the harmonic balance to align the crank. Remove it (you'll have to to change the belt) and you'll find a mark on the crank hub and a v-notch in the inner lower timing cover.
        Where can I buy the updated sprocket? For replacement if the piece, I assume it only goes on one way like the sprocket uses a 'key' to be installed correctly? (like a notch so it only fits on one way)

        And to align the crank? what do you mean do not use the harmonic balancer?

        Comment


          #5
          FYI, I am following Pelican Article DIY, with 2-3 other DIY references to I have a couple of sources for the steps I take with the timing belt service.

          Thanks.

          Comment


            #6
            Originally posted by DarkLordFreeman View Post
            Where can I buy the updated sprocket? For replacement if the piece, I assume it only goes on one way like the sprocket uses a 'key' to be installed correctly? (like a notch so it only fits on one way) And to align the crank? what do you mean do not use the harmonic balancer?
            Yes, the new style cam gear has a keyway of sorts. a circle cut into the gear with a dowel pin that will align it to the cam. you should be able to find someone selling one on here. I can't recall if i have a spare one lying around or not..

            Pull the 6 bolts from the dampner and crank pulleys out and pull off the dampner. behind it will be the gear for the actual timing belt and you'll see a V notched in the timing cover and a line machined in the timing gear
            1989 JDM-Tech 2
            2010 335 D for daily

            Comment


              #7
              ^^Do you have one lying around sir?

              And I should search the classified ads, but is there a place I can order a new one if I can not come across the can sprocket piece? I would like to get the car back together.

              Comment


                #8
                My mistake guys, there is a very faint alignment arrow!

                I am still looking to grab a revised can sprocket, so where can I buy one of these???

                Comment


                  #9
                  Originally posted by DarkLordFreeman View Post
                  ^^Do you have one lying around sir?

                  And I should search the classified ads, but is there a place I can order a new one if I can not come across the can sprocket piece? I would like to get the car back together.
                  To start you could post up in the Parts Want to Buy section, and in a Regional sub forum, maybe contact someone like user MR 325. The intermediate shaft is probably stamped stl as well. You might look around for a 'late' cast steel to to go with your replacement cam sprocket. I swapped mine out as well GL
                  Last edited by 36brua; 07-22-2013, 10:18 AM. Reason: add info
                  My CA legal M60 swap

                  The happening in our garage

                  Comment


                    #10
                    11-31-1-714-988 gear wheel,tooth 1 1 57.85
                    cam


                    11-31-1-717-398 gear wheel,tooth 1 1 37.17
                    intermediate



                    go to the dealer, they are cheap
                    "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." - Winston Churchill

                    "People sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf" -George Orwell

                    Comment


                      #11
                      I doubt the dealer would hve them in stock. Either ask a local friend with a spare m20 around or hit up a junk yard.
                      Shawn @ Bimmerbuddies
                      Bimmerbuddies LLC
                      717-388-1256
                      2971a Roundtop Rd, Middletown PA 17057
                      bimmerbuddiesllc@gmail.com

                      Comment


                        #12
                        Thank you all. I sourced the revised/updated parts. So I will be getting those. Thank you.

                        Comment

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