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Daytona engine mounts

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  • Transmission / Overdrive: Daytona engine mounts

    I'm still fighting vibration in the driveline of my 64 Daytona, 259, 700R4. When getting alignment done on the front end the tech recorded that the passenger side suspension was offset to the rear a small amount, 1/8". At the time his frame machine was tied up with a complex job so he aligned the car and opined that he didn't think the driving would be affected. He was right in that the car goes down the highway nicely. But

    There is still a strong vibration that feels like a bad universal joint or pinion bearing. The rear has been totally redone with all new bearings and one new axle shaft. The drive shaft built for the car by a professional is balanced and of course the u-joints are new.

    Grasping at straws now, is it possible that the damage to the frame/suspension also resulted in a displaced engine mount and that when fabricating the transmission mount we fastened the tailshaft off the centerline of the chassis causing horizontal misalignment of the trans/pinion?

    I've been told that the factory offset the V-8s to the right to clear the steering gear. Is this true?

    Thanks for any help or ideas, Grant

  • #2
    My Hawk engine is offset to the right, there are two sets of motor mount holes about ~3/4" apart. It appears to me that the left side mount support would not clear the fuel pump (R2) if the engine were offset to the left side holes. Not sure about the steering box, I'll take a look when I get the chance. Try having someone follow you while you're driving to see if the car shows signs of "dog tracking". A good collision shop should be able to measure your frame, or you can make a trammel bar with some 1/2 electrical conduit, a nail and a magnet with another nail or some way to clamp another nail at different points. Takes two people, but you can measure enough points to see if the frame is out of square. Sounds like you have a driveline misalignment, possibly.


    • #3
      There are many types of vibrations that can happen in a car, If your tech is any good, he should be able to feel it, hear it, and have a clue where it is coming from.

      One of the very first things to consider is how bad is it? What speed is it, what conditions is it present the most?

      Give the lug nuts a torque, look at ujoints, go under there and look at things, push and pull on things and give it a GOOD safety check.

      Many ways to check and eliminate the rest. Just sitting in park and reving the engine to different (steady) RPMS, may let you know if the flex plate or convertor has a problem.

      I won't go into all the tests I would do because some are dangerous, and the lists go on and on- and most are actually in the shop manual. If you have a good tech, he will know what to do.

      I've had vibrations from the torque converter, flex plate (yes even on a GM trans),, Wheels-bent and out of balance, tires- under inflation, flat spots from skidding, or sitting,, U joints- even brand new ones, miss aligned engine mounts, bent axles, bad wheel bearings, loose lug nuts, bad shocks, bad struts, broken leaf springs, bad driveline center support bearings, and even a bad transmission shaft.... and once in South Dakota, a bad road!

      Most of this list can be eliminated in about 45 minutes of safety checking, and test driving.

      Good luck!


      • #4
        I made an appointment with the frame alignment shop today and will get in next week. He has a state-of-the-art shop and techs. I watched them laser straightening a '36 Airflow that had been severly T-boned. It is quite amazing to watch. Meantime I've been trying to think of all the possibilities we can check while he has the car on his rack. If the front engine mount is out of place and the newly fabbed trans mount holds the trans in that out-of-line position, then we will not solve the problem by pulling the engine mount into the proper spot without repositioning the trans mount.

        The vibration is quit severe and feels like a bad u-joint, a really bad u-joint. At highway speeds it rumbles while accelerating, makes an equal but different noise when decelerating and is not as loud when neither gaining or losing speed. The 259 is freshly rebuilt and balanced. The transmission has about 200 miles on a rebuild by the best trans man around. The driveshaft is newly custom made by a local specialist. Rims and tires are new. Shocks are new and all the bearings in the rear axle were replaced last week with no noticable change in the vibration. Drive line alignment seems to be the only variable left and that is why my question about engine location. The engine needs to be in the correct position so that all the adjustments of angles gets the right line from engine to differential. Before tearing the rear axle down I would have given 100 to 1 odds the problem was a worn out pinion bearing having experienced that condition in a brand X recently. There was a bad axle bearing but the pinion was fine but we replaced everything anyway.

        R2 Hawk, do you know if the output shaft of your trans is also offset the same amount as the engine? Appreciate all the help. Grant


        • #5
          "R2 Hawk, do you know if the output shaft of your trans is also offset the same amount as the engine? Appreciate all the help. Grant ....."

          I will have to check. I'm planning on putting it up on my hoist in the next couple of days, I'll let you know. I'd be willing to bet your frame guy could figure out a way to check engine/trans to drive line alignment with his laser frame alignment setup.


          • #6
            You can play a 'tune' with the gas pada lwhile doing 35 MPH if it is a worn out pinion/ frt bearing. You'll also find it with the safety check I mentioned. Grab the yoke and try to move it straight up and down like you would check a U joint.