No announcement yet.


  • Filter
  • Time
  • Show
Clear All
new posts

  • vibration

    I have a bad vibration when decelerating at about 40 mph or more. The car runs smooth otherwise. Any ideas? I just purchased the car and it has a rebuilt motor and a float a motor.

  • #2
    I have heard that it could be a bad universal joint but I have no personal experience.


    • #3
      I had the same thought, but it does not make any noise when shifting. I have had that happen in other cars. I greased the heck out of it just in case.


      • #4
        I have been in many A's that do the same thing including mine. decell only, it goes away on accel
        4~ Tudor's
        1~ Coupe

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

        Mitch's Auto Service ctr


        • #5
          the float mounts can be subject to vibration. Miles insisted on them for his car, but soon removed the front due to vibration, and went back to the yoke mount, problem solved. He had been cautioned by other club members about this, but wanted to try it

          Also, for either type mount, if your rear mount bolts are even a little loose, you will get decel vibration
          I had that happen to my '31 Deluxe Touring with OEM mounts
          Last edited by tbirdtbird; 02-02-2018, 10:08 AM.


          • #6
            Thanks I will check the bolts


            • #7
              I have OEM on my cars too.

              arvon read this FAM thread especially MIke K's post #18 reply.. This is from the tech forum

              FAM tech thread
              4~ Tudor's
              1~ Coupe

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

              Mitch's Auto Service ctr


              • BILL WILLIAMSON
                BILL WILLIAMSON commented
                Editing a comment
                Probably that flinky tail pipe hanger!!!
                Use a universal rubber strapped hanger.
                Last edited by BILL WILLIAMSON; 02-02-2018, 01:44 PM.

            • #8
              thanks Mitch, I will check the mounts. the car was not used much in the past 18 yrs. When I purchased it there were a lot of rubber parts that needed ;replaced may be the motor mounts are dried up


              • #9
                One thing to try is John Deere Corn Head grease in the U-Joint. Conventional grease too thick and does not flow well after it is thrown off by centrifugal force. Several of the fellow A owners in my area have tried the corn head grease and have noticed an immediate decrease in the deceleration vibration. Of course if the U-Joint is worn out no type of lube will help. I don't think I have ever driven any A that did not have at least some vibration or resonance during deceleration.


                • BILL WILLIAMSON
                  BILL WILLIAMSON commented
                  Editing a comment
                  A Friend of Chiefs' restored a BEAUTIFUL Model A & shortly sold it, because it didn't go "HUUUUUUM"!!!
                  Dad Sad

              • #10
                This is not my first model A but it is the only one that vibrates that bad. My 28 with solid motor mounts is much smoother.


                • #11
                  We use corn head in the universal and it does leak a minor drop or 2 after warming up.


                  • #12
                    Model As have ridged power train mounting & body on wood blocks, SO, some noises are COMMON!
                    OLD Chevs were mostly WOOD & are quieter!
                    Dad Simple


                    • #13
                      Originally posted by arvon View Post
                      This is not my first model A but it is the only one that vibrates that bad. My 28 with solid motor mounts is much smoother.
                      If you are in neutral and standing still, then rev the engine and let it decelerate, does it then vibrate while slowing down?

                      If not, then it sure would seem to be a driveline problem, and I wouldn't overlook the nuts coming loose on the double pinion bearing.


                      • BILL WILLIAMSON
                        BILL WILLIAMSON commented
                        Editing a comment
                        I ALWAYS worried about those nuts. What a CRUDE method of tightening them!
                        "ALMOST" like Cave Man Skills----------Ever have a rear end LOCK up, while buzzing down the road?---Just KISS it "GOOD BY"!
                        Last edited by BILL WILLIAMSON; 02-04-2018, 10:25 AM.

                    Related Topics


                    • Jordan
                      Can a transmission cause vibrations?
                      by Jordan
                      The basis of this post is to ask, can a transmission cause vibration that is felt throughout the car? This is in my "new" car, which is a mix of everything under the sun. Here's the backstory:

                      It has a *gasp* mustang II motor in it (2.8 liter). It is mated to a syncro 40 Ford transmission with a model a driveshaft and rear end. I just had a friend pull the motor & transmission...
                      10-21-2019, 09:11 AM
                    • Chuck Sea/Tac
                      Engine vibration
                      by Chuck Sea/Tac
                      I have had a annoying vibration at an idle sometimes and around 1000 RPM roughly. It doesn’t seem to matter up or down this has been going on for a couple of years.. I recently noticed that my engine had dropped in the front and the crank wouldn’t go this point the vibration was barely noticeable. I ordered new springs and lifted the engine up replace the front engine mount Springs and...
                      01-10-2019, 06:10 PM
                    • BTERRY1
                      Loud vibration
                      by BTERRY1
                      When engine braking, I get a loud vibration. Sounds like sheet metal from somewhere. Anyone experienced the same? Hard to try and isolate while driving. It’s a pretty low frequency....
                      05-08-2021, 07:18 AM
                    • Licensed to kill
                      Cause for concern.
                      by Licensed to kill
                      I rebuilt my engine a month or so ago and it's been running like a champ. However, it has been developing a noise that has me more than a bit concerned. The best way I can describe the noise is like a cross between a knock and a rumble. It started perhaps 5-600 miles after reassembly, does it at low RPM and is loudest if lugging the engine even just a little bit. It would initially go away if I retard...
                      09-24-2020, 08:24 AM
                    • Beauford
                      A little shudder...
                      by Beauford
                      I received and installed Bert's beautifully rebuilt Zenith I purchased. I dialed it in as the motor didn't like the settings out the box. Engine runs fine but there is a bit of a "shudder". All A's I assume have a little vibration but when you look at the bed of my truck. Vibration, then a shudder, vibration and then a shudder. I don't know whats normal and what's not with Model A's. Any...
                      05-21-2018, 08:35 AM
                    • Captndan
                      motor mounts
                      by Captndan
                      New touring engine. original mounts float a motor?
                      07-21-2019, 01:53 PM
                    • canadian
                      by canadian
                      First summer owning and driving a Model A, 29 CCP. 3200km, had some issues but nothing serious , few things I need to give some attention to over the next 5 months of winter, got a steering freeplay issue and windows dropping on there own. But I have a overall vibration issue , at idle ,accelerating , even when truck is coasting along at speed.. no throttle , seems like always got a buzz or a drone...
                      12-13-2018, 06:46 PM
                    • Standing Elk
                      Vibration when against compression
                      by Standing Elk
                      My friend has a 31 pickup. He said that it runs smooth when idling or going down the road. However when he slows down against compression, like beginning to slow down for an upcoming speed zone, he says a vibration will start at about 35 mph and then quits at about 25 mph. The vibration does not occur if he is acceleration through this same speed range. Any ideas? Thanks
                      04-25-2018, 11:09 AM
                    • Jm29henry
                      Motor Munster greenfield village
                      by Jm29henry
                      Has any one heard how motor Munster is going with the new rules?
                      06-17-2017, 06:37 PM
                    • 1930 Closed Cab PU
                      Motor Noise
                      by 1930 Closed Cab PU
                      Not a good day for me yesterday. Was going to complete a rebuild/test of a spare distributor, and install/test a Berts Carb

                      Rebuilt motor, has 500-600 miles on it.

                      Went out and started the truck - good. Swapped in a Berts Core/bushings/shaft with used original parts I had. Truck would not fire, ammeter would not wiggle. Found that at full retard the lower plate pigtail...
                      04-24-2019, 10:43 AM