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1963 Continental Transmission Shifting Questions & Follow Up

Hi Bill,

When I accelerate the transmission changes up through the gears correctly and smoothly, if I'm in third and take my foot off the accelerator then press down on it slowly the trans will always change down a gear no matter whether I'm doing 30mph or 60mph. I've adjusted the kickdown and manual linkages as per the maintenance manual but still no joy. I have also checked the vacuum unit for leaks and it seems fine. Any ideas?

Thanks a lot -

Aaron

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Greetings Aaron -

After reading your issue and what you have checked so far, there is one important item that we can think of. The transmission kickdown linkage and calibrated spring must perform as designed. There is a very important spring near the carburetor at the linkage that governs the downshift kickdown linkage. I say governs because that spring is calibrated to a special rate in order to allow the bellcrank to activate the transmission kickdown linkage only during specific throttle movements. A drawing of the linkage and spring is shown in your service manual. Could an incorrect spring be installed on your car? Did the transmission previously perform o/k? If the problem suddenly began without the spring being changed, there could of course be an internal transmission issue. Let us know what you find.

Sincerely,

Bill

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Hi Bill,

The transmission was operating correctly with the original springs that you spoke about. The problem just started out of the blue. I bought new springs from you guys hoping that would fix the issue but unfortunately it didn't. Because a lot of things are vacuum operated on this car does that mean if even one hose is off, even if its not transmission related, that will effect the trans operation?

Thanks

Aaron

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Hi Aaron -

A small vacuum leak from another component will not noticeably affect the vacuum to and the operation of the transmission modulator valve. Vacuum to that valve can be tested with a vacuum gauge tee'd into the vacuum line that routes down to the inlet port of the valve. You should also check that uninterrupted vacuum is actually available all the way down to that port. It couldn't hurt to remove the valve to inspect for internal fluid leaks and that the actuator pin is present and intact. A bench check of the valve for movement with vacuum could also be done. Since you have been changing springs and adjusting the linkages I am assuming that they are correct and adjusted properly as you have stated. A good test to find out if the kickdown linkage is maladjusted or causing a problem is to disconnect the rod at the bellcrank temporarily and tie it away from other parts to a nearby bracket on the engine. It must be tied in the no kickdown throttle off position. The transmission will then receive no instruction from the linkage to downshift. Road test the car to find out if the issue still exists. If the problem goes away, the linkage and spring adjustments etc. need to be revisited. If the transmission was fine prior to this downshift issue and no adjustments or modifications to anything that could affect the shifting was performed then you may need to have a technician at a transmission shop familiar with this type of transmission road test the vehicle in order to evaluate the situation.

Sincerely,

Bill