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A mysterious overdrive transmission missing all the OD parts.


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I reviewed all the outstanding & very informative posts on freewheeling standard & overdrive transmissions, (so I won't bore everybody with the good, bad & ugly about freewheeling). I recently acquired a perceived overdrive trans that doesn't have any OD components. What is it & why does it exist is the purpose of this post. It has all the markings indicating it is a 1936-37 Chrysler Windsor or Imperial OD. T-86 - 1P, R-6-1 Apparently it came out of a batch of 4 identical units from Pennsylvania, one of the states that outlawed freewheeling transmissions back in the day. While the early OD transmissions were not designated as freewheeling units, they did have a freewheeling component. It has no linkage to activate the OD unit, or holes in the case for same.

 

This trans is painted black & is NOS. Cosmoline, along with no signs of wear on any rotating component attests to it being unused. I inserted a long ice pick 3" into one of the two bracket holes in the rear case before I hit a shaft. It would have been only 1/2" if there was an OD drum inside, (I've rebuilt several old Mopar OD transmissions), so I have a good idea where everything is.

 

Were there enough lawsuits from Mopar owners, Studebaker, Graham, etc, to force Borg Warner to come up with an alternative to satisfy the ban, just because it has a freewheeling component? "Freewheeling" was probably the determining factor in any legal cases.

 

This OD appears to have standard gearing without overdrive & is the exact same length as the full OD unit. This could be a replacement unit that uses the same driveshaft & hand brake activating rod, saving somebody the costs of going back to a shorter unit, along with fitting nicely around legal verbiage.

 

There must be some information out there that can explain why this transmission exists.

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3 hours ago, JACK M said:

If you get lucky maybe you could find the parts to make it into OD.

I thought of that, however, machining the holes in the case for the levers & shafts would require more equipment than I have. Better to find a complete OD trans that has bad gears & use the rear case & innards.

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Interesting Google search did not bring up any actual laws against "Free Wheeling" or "coasting in neutral".  Many car makes from 1931 till present day still have versions of freewheeling. 

 

Electric cars are never in gear, unless they have regenerative braking...still not in mechanical gear.

 

The early systems of overdrive used centrifugal force to change to overdrive, no solenoids or electronic assist.

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On 2/25/2024 at 3:42 PM, Graham Man said:

Interesting Google search did not bring up any actual laws against "Free Wheeling" or "coasting in neutral".  Many car makes from 1931 till present day still have versions of freewheeling. 

 

Electric cars are never in gear, unless they have regenerative braking...still not in mechanical gear.

 

The early systems of overdrive used centrifugal force to change to overdrive, no solenoids or electronic assist.

I drive a 2018 Volt & thoroughly enjoy the regenerative feature which doesn't have a freewheeling aspect, so I would say it is always in gear, (even though it is based on electrical resistance), since there is no neutral.

 

I'll check into any bans on freewheeling which may have come from particular auto manufacturers, for liability reasons, rather being outlawed.

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On 2/25/2024 at 10:20 AM, JACK M said:

There was one of those in a 37 Desoto I parted out once. Totally mechanical, no electrical parts involved.

I never drove it but I kinda liked its simplicity.

That 37 DeSoto had a fully functioning OD I assume. I know 39 on had electric solenoids. I do like the simplicity of the non-electric ODs.

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