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Dialing in the Flywheel Cover

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  • Dialing in the Flywheel Cover

    For proper operation, the engine crankshaft must be exactly inline with the transmission input shaft. This is accomplished by dialing in the flywheel cover. You need to measure the cover at 9, 12, and 3 o'clock positions, and use shims under the top two bolt holes until the three measurements are within .006" of each other.

    To keep the crankshaft clearance from messing up your measurements, the front of the engine should be pointed down. This will keep the crankshaft forward for all the measurements. After I get things dialed in I add a bit of grease to the shims so they don't fall out of place while the bolts are removed to add the throttle linkage after the engine is installed.

    I was lucky enough to find an original crankshaft turning tool at a swap meet, but you can also make your own. As I turn the tool from the 9 to 12 position I hold the tip of the dial indicator so it doesn't snap into the open space. This is a precision instrument and needs to be handled with care.

    In the second picture I am checking the flywheel mounting flange for runout. Hopefully this will be zero, but some crank grinders don't know the flange MUST be concentric to the rear main journal.

    Dialing in Flywheel Cover.jpgDialing In Flywheel Cover2.jpg

  • #2
    Tom, shouldn't the top two bolts be tightened down before taking the reading. It seems tightening these two might throw the readings off.


    • #3
      I'm not Tom but he put this together for me quickly as a demonstration to make this thread. As he stated the front of the motor should also be pointing down when measuring.
      1~1931 Tudor ~ Dad
      2~1930 Tudor's ~ Lucy & Paul

      Henry Ford said
      "It's all nuts and bolts"

      Mitch's Auto Service ctr


      • #4
        Another thing, the flywheel locates off the dowel pins. Shouldn't the pins be what you indicate? I could dial in zero-zero on the OD of the the flange, but if the pins are off, the flywheel will be off too. Jist sayin'


        • #5
          In the upper pic, the top 2 bolts do need to be torqued to get a proper reading. You have to use shorter bolts when the accelerator bracket is off. I believe his pic is a generalized setup pic.

          I know of no way to indicate off dowel pins.
          You could give both the crank and the FW to your machinist to determine concentricity once assembled.
          By the time you get to the pic Tom posted, it is too late, but can act as a double check.
          If the flange is on center, then mount the FW and check the FW for center thru the starter hole.

          While we have dial indicators on the shelves here, we do not have the fancy crossbar Tom has. We just use a piece of angle iron bolted to a crank hole, and then use a feeler gauge to measure the spacing at 9, 12, and 3. This is an easy way for a hobbyist without a pile of specialized tools to get the job done. We then check it again with the FW mounted, again using a small section of angle iron bolted to a FW hole with a bolt facing down toward the housing.

          At another location I have seen pix and vids of this process being done with the engine horizontal. Might as well skip it if done that way, the crank end-play will get you every time. The nose of the engine MUST be facing down, so you will need the type of engine stand adapter that bolts to the side of the block
          Last edited by tbirdtbird; 01-13-2018, 02:30 AM.


          • #6
            Right, as Dave and Mitch mentioned, the front of the engine needs to be pointed down when dialing in the flywheel housing, and these pictures were a quick take to show how to measure the run out.
            I bought a Model A engine at the Grand Rapids, MN swap meet in the early 80's, and the seller remembered me, so when I went back a couple years later he pulled the KR Wilson flywheel turner out of his car and asked me if I wanted to buy it for $10. I couldn't get my money out fast enough. What a lucky buy, but that is the only KR Wilson tool I own. Some guys have been lucky enough to get quite a collection of them.


            • #7
              I was horizontal on the last time I did mine,when barring the engine I just held forward pressure on the bar to fight against end worked but i agree on horizontal for both housing runout and flywheel runout,its just easier..can anyone identify this housing?


              • #8
                Mine's in the car and I ain't taking it out. I think I'll indicate the crank flange. (Set the indicator stand on the block and put the indicator tip on the flange and see just how much it does move fore and aft) It may just not move. Then again it may flop back and forth as much .020 or more in which case I'll have to find another way. Maybe a temporary shim?


                • #9
                  Originally posted by CM2 View Post
                  I was horizontal on the last time I did mine,when barring the engine I just held forward pressure on the bar to fight against end worked but i agree on horizontal for both housing runout and flywheel runout,its just easier..can anyone identify this housing?
                  I did the same thing when I dialed in my 29 Tudor, as the engine was installed, and I was doing a clutch replacement due to bad clutch chatter. I installed a good looking used pressure plate, new disc, sanded the flywheel with my 1/4 sheet electric sander, and dialed in the flywheel cover. I don't know what part caused the shaking, but my car went from a paint shaker on clutch engagement to smooth as an automatic.

                  Just be sure to press the crankshaft forward for each reading of 9, 12, and 3 o'clock positions, if you dial it in horizontal.


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