Floating Power Motor Mount Rebuilding

by John Hertog

Floating Power motor mounts were used on Chrysler 300's in 1960, 1961, 1962, 1963 and 1964. There were two distinct units available, depending on whether the car was a Long Wheelbase ( 300F and 300G ) or a Short Wheelbase ( 300H, 300J, and 300K )

  • Part numbers for the long wheelbase mounts are : 2128571 and 2128572

  • Part numbers for the short wheelbase mounts are : 2120237 and 2120238

    Here's a picture of a pair of long wheelbase mounts ; they are "as installed" in car. The engine would fit between the two . On a long wheelbase car, the ears face forward.

    These mounts are quite prone to failure: age has taken its toll, oil has dribbled down from the valve covers and soaked the rubber, and much horsepower and torque has been applied over years and years ! They start to develop cracks in the areas where metal is bonded to the rubber. Once a crack becomes visible, its only a matter of time until the mount fails .

    Frankenmount to the Rescue (or, how to repair you old tired mounts)

    1. First step, if the mount is already collapsed, is to line it back up again, so that all is where it should be...
      Then, drill a hole straight thru the mount, as shown, front to back .

    2. Insert a piece of threaded rod all the way through the mount as shown.

    3. Cut the threaded rod so that the ends are just a bit recessed inside the mount

    4. Mig-weld the rod ends to the mount body ...

    5. Here's the weld, before grinding...

    6. ...and after grinding !

    7. A little paint, and you're all done. These suckers will never fall apart again !

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