This week’s American Powertrain Parting Shift is cool because it is not only different, it’s educational! You are going to see a dude diving and explaining the custom transmission setup that he installed into his F-150 Ford truck. Basically he has a four speed and a Ranger III auxiliary transmission made by Advance Adapters. The whole program looks cool and nearly factory. What we like best though is the fact that the driver kind of talks us through the operation of the twin stick system, why he did the swap and how he normally operates the truck.
Look, we know it is kind of overkill and unnecessary in the modern world but it’s cool! This thing can be driven as a normal four speed truck if you want and if you are pulling loads you can split the gears to get stuff moving from a stop. We also see the benefits of driving the truck like a 5-speed by using the normal four gears and then dropping the thing into the OD to get maximum mileage potential on the highway.
The owner of the truck explains his logic better than we ever could. We dig this –
The FAQs attached to the video by the guy who owns the truck are awesome:
Why the hell did you do this?
Because I wanted to, I love driving a manual transmission. I used to drive semi trucks, did it for 12 years. Since I no longer drive trucks this is the next best way to get my gear jamming fix.
Is this factory?
No I removed the stock 5 speed transmission and installed this Overdrive with an older 4 speed transmission.
Can I do this to my truck?
Maybe. They make these units to work with Ford and Chevy 4 speed transmissions. They also make one for a Toyota to adapt a chevy engine to a Land Cruiser 4 speed transmission. That is it, only 4 speed transmissions for Ford, Chevy, and certain Land Cruisers. THEY WILL NOT WORK WITH NEWER 5 OR 6 SPEED TRANSMISSIONS.
Why the f*&k would you do this to an F150?
It may seem like overkill but it really is not. This Overdrive was first made back in the 70’s by a now defunct company, at some point Advance Adapters bought the rights and the tooling and started making these units. If you had or have an older truck with a granny 4 speed this unit was a wonderful upgrade. It’s main function was to give you an overdrive gear. It just so happens that you can also use it as a gear splitter.
How does splitting gears work?
It boils down to simple math. My 2nd gear ratio is 3.03 to 1 My third gear ratio is 1.78 to 1. However if I use my Overdrive which has a ratio of .79 to 1 in 2nd gear it gives me a gear halfway between 2nd and 3rd. I have split the gear in half, hence the name splitting gears. It works like this… 2nd gear 3.03 to 1 multiply by Overdrive ratio of .79 to one. 3.03 x .79 = 2.39 that ratio is between 2nd (3.03) and 3rd(1.78) so 2nd Over is a gear in between 2nd and 3rd.
