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Transmission Information & Noise Guidance

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  • Transmission Information & Noise Guidance

    Original thread link



    Symptom: Noise from transmission, effected by clutch pedal movement.

    Clutch Throw Out Bearing Noise: high-pitched rubbing noise with only slight
    pressure on clutch.

    Pilot Bearing Noise: high-pitched noise when clutch is fully depressed.

    Noise When Clutch Pedal Depressed:
    -throw out bearing, worn, damaged, inadequately lubricated
    -pilot bearing (in flywheel) worn, damaged, inadequately lubricated
    -crankshaft end play should be checked

    Noise When Clutch Pedal Released:
    -Transmission oil level low
    -Misalignment of transmission (more noticeable at low road speed)
    -Clutch disk hub loose
    -Clutch disk springs weak, popped out of cage, or broken
    -Weak or broken return spring on throw out bearing sleeve
    -Sticking throw out bearing sleeve (clean slider, lubricate)
    -Transmission roller bearings worn, damaged, inadequately lubricated
    -Transmission gear damage.

    Other deceiving noises that can “travel” include noise from speedometer cable, starter Bendix, generator bearing/bushing, and water pump bearing.

    Firstly, adjust the clutch for one inch of free play. If noise is eliminated, good.

    Secondly, grease the throwout bearing sleeve. If noise is eliminated, good.

    Thirdly, if noise is still present, the transmission will need to be separated from engine. Best to remove rear end and drive train, unless major engine work is required and, if so, then take it out as a unit with the engine.

    1. This is to diagnose noise coming from transmission and does not address clutch drag/slippage/chattering/pulsating/slippage out-of-gear/lock-up.
    1. The Model A transmission takes three “needle” or roller bearings and two sealed bearings. "Needle"/roller bearings should have their axles poking through their collars, not set into dimples in the collars.
    1. On my two rebuilds I used Bratton’s for parts and cannibalized a decent cluster gear set from an old transmission. Snyders and Berts have received many favorable comments on their transmission parts over the years, also. Buy quality and buy it once. Inspect what you buy for small rust spots (too long on the shelf).
    1. Strongly recommend reading Tom Endy’s articles on the Model A Transmission, found here:
    1. Good pictures of transmission components can be found by purchasing a set of Model A Shop drawings from MAFCA here:
    1. Vince Falter’s FordGarage has an informative, animated video on transmission gear changing created by a VFF member, here:
    1. I discarded my failed needle bearings years ago without taking pictures. One bearing had disintegrated into a handful of rollers with damaged end rings.
    1. Most rebuilders strongly recommend against using STP in a Model A Transmission.
    Last edited by BudP; 02-11-2018, 04:06 PM. Reason: I have been advised by excellent authority that "needle" bearings, while descriptive, are better referred to as roller bearings. The main catalogs describe them as roller bearings or simply

  • #2
    Schwalms cutaway engine / trans!
    2 1930 Tudors

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

    Mitch's Auto Service ctr


    • #3
      Basic parts that should be included in a Trans Rebuild,, By Tom Endy

      Check out Mr. Endys other top notch trans & technical articles.

      2 1930 Tudors

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

      Mitch's Auto Service ctr


      • #4
        Transmission Specifications

        Gear & Shaft Material Chromium alloy steel

        Gear Ratios
        High-1:1 (100%)
        2nd-6.89:1 (53.8%)
        Low-8.75:1 (32.04%)

        Main shaft front (ball) 1208;
        Main shaft rear (ball) 1306

        Transmission Case Length 6.560" to 6.565"

        Case Front Bearing Hole 3.1497" to 3.1507" diameter

        Case Rear Bearing Hole 2.835" to 2.836" diameter
        2 1930 Tudors

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

        Mitch's Auto Service ctr


        • #5
          Clutch Specifications

          Material Molded asbestos composition

          Pressure Plate Weight 15 pounds

          Clutch Disc Weight 2-1/2 pounds

          Pivot Pedal Pressure 30 pounds

          Clutch Facings 9" diameter, 9/64" thick

          Inside Diameter 5-3/4"

          Total Acting Surface Area 75 square inches

          Clutch Pedal Clearance 3/4" for multiple disc, 1" for single

          Clutch Release Bearing Hub 2.065" diameter

          Clutch Throw Out Bearing B7580 or B7580T

          Clutch Pressure 1100 pounds
          2 1930 Tudors

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

          Mitch's Auto Service ctr


          • #6
            2 1930 Tudors

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

            Mitch's Auto Service ctr


            • #7
              I don't think I posted this picture before, and as I recall I took this at the Gilmore Model A museum in Hickory Corners, Michigan. It's in high gear.

              Tranny Cutaway.jpg


              • #8
                Does your trans pop out of gear?

                Original thread link

                The very first thing to do is to remove the shift tower.
                The parts there may be so worn that it is never fully going into second.
                Here is what can be worn out:
                1. shift forks, look for wear marks, compare the 2 forks
                2. the rivet pins that hold the forks to the rails can loosen over time and thus not give you full throw
                3. the rails can be worn where the notches are
                4. the detent spring can be weak
                5 the detent plungers can be worn

                I have worked on towers that ALL of these problems at the same time.
                Do not use rivet pins when you reassemble, use split pins, they are much stronger.
                When I rebuilt Miles' tower, I had trouble getting quality parts.
                I ended up at Bert's, he had re-pop forks that were PERFECT in size, and he had the split pins
                I only had to replace the 2-3 shift rail, the other was good. You could see the notch had been widened on the 2-3 rail. And I only had to replace the 2-3 fork
                I am not convinced the repop detent springs are as good as the originals. Try to get a good original, from Bert's, he has a lot of quality used parts. In addition, I added a single 1/4" ball bearing to the spring tunnel to make the detents even more positive.

                As far as any of the repop springs, I am not convinced any of them are any good. For example, the cam plunger repop spring is no where near as strong as the original

                I actually did not end up using the re-pop plungers, either, in my case the originals had a much better shape to them (they were not worn) and fit into the notches better

                While you have the tower off, carefully inspect the gears for chips and other defects. Be sure to look at BOTH sides of the gears, since one side wears on accel, the other side wears on decel.

                You did not say, does it pop out on accel or decel?

                Good luck. My experience is that 90% of pop-out problems arise from the tower..
                If the tower is perfect, and the gears are good, then you have to begin to think about the 2 roller bearings inside the cluster gear.

                Drain the case and see if you get back a large amount of metal chips/filings. A small amount is normal.

                I would not drive the car until this is fixed, the wear will continue at a rapid rate.
                And whatever you do, do not drive the car by holding the lever in second gear to keep it from popping out, which is what the PO may have done, this will destroy the tower parts in short order


                • #9
                  One thing that bothers me is the worn undersize ball that can jump around in the shift pattern and even (Extreme) cause going into two gears at once. I like to weld the ball up and forge and grind it to size. First you weld it, I used MIG wire (Not my first choice) and then formed it on the anvil. Forging compresses the metal and toughens it. With a little grinding here and there as needed, to shape and size the ball. IIRC, the slot the ball must slide in is .500 +.Miking the ball and just giving it a slip fit into the slot on an angle (Very important! Make sure you're using the same angle that the shifter works at, not perpendicular!) If you don't fit it to this angle the shifter might bind on you. So when you're satisfied that it will fit nicely and move freely, if you have access to Kasenite, case harden the ball end and you're done. I lost my Kasenite a while ago so I have to do without and it's working fine, but it would make me feel better if I had been able to harden it.


                  • Tom Wesenberg
                    Tom Wesenberg commented
                    Editing a comment
                    As mentioned, check the second gear for being loose on the shaft. It should slide on the shaft, but not rock back and forth at all if you try to twist it on the shaft.

                    If you have to pull the tranny, then is a good time to check the flywheel cover for being properly dialed in.

                  • tbirdtbird
                    tbirdtbird commented
                    Editing a comment
                    Terry mentioned one thing I forgot, the ball on the end of the shifter has to be .500 round. Any parts that are worn will prevent the gear from fully engaging and it will jump out.

                    We weld up the ball if worn, the we stole an Idea from Tom W, we use a washer with a .500 ID to use as a standard as we grind the welds down carefully

                • #10
                  I had a second gear popout problem recently and did the tower spring tension improvement with no luck. I decided to pull the trans and go further after feeling the second third slider on the main shaft. As it turned out the gear was loose on the shaft. I went down to my local dealer and picked up a shaft and tried a new gear they had, and it was sloppy. I told them if I can't find a gear that fits without slopping around on the shaft I'll return it. I had bought a new gear on the original rebuild and found it was sloppy on the new shaft also. Did some more digging in my parts stash and found a used gear that fit snug. Reassembled and trans works perfect. In the past I read somebody posted Henry suggested replacing the shaft at the same time a gear was replaced. That poster claimed it was Henry's way of selling more parts. Maybe so but the bottom line you can't have a gear that has slop on the shaft. That goes for first reverse gear also.
                  Last edited by Dennis; 06-04-2018, 06:38 PM.


                  • #11
                    If the transmission vent hole on the shift tower gets blocked with crud the fluid will foam and leak out..

                    2 1930 Tudors

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

                    Mitch's Auto Service ctr


                    • #12
                      I have a problem with oil seeping out the top of the shifter and the weep hole. Recent rebuilt. I blame it on oil that does not have anti foaming additive in it. I bought it local because of n the past oil was damaged in shipping. I haven't looked for anti foaming additive. Can anybody suggest what to use?


                      • Mitch
                        Mitch commented
                        Editing a comment
                        What about draining it out and using the right stuff.

                      • Dennis
                        Dennis commented
                        Editing a comment
                        I'll have to take a chance the next order of bottles don't rupture in shipping.

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