MTFCA Forum

I was reading some news today and came across a new AI search engine called perplexity.ai that is said to probably take over
from Google as the number one search engine. I typed in "How does the Model T transmission work" and got this answer. I like how it describes what the drums do but I think it left out some details about reverse and stopping.


The Ford Model T transmission is a unique system that uses three pedals and a lever to control the vehicle's speed and direction. The left pedal controls the gears: when pressed all the way down, it engages the first gear; when halfway down, it's in neutral; and when released all the way up, it shifts the transmission to its top gear. The center pedal is for reverse, and the right pedal is the brake.
The Model T has two speeds forward and one reverse. The transmission works by using a system of bands and clutches. When the left pedal is pressed down, it tightens a band that stops the low-speed drum, forcing the output shaft to turn through the planetary reduction. When the pedal is released, it engages the high gear clutch, which is a disk clutch that locks the transmission into direct drive. In between, both the band and the clutch are disengaged.
The transmission also includes a set of triple gears that rotate on pins with the flywheel, transferring motion through the transmission. The "neutral" of the Model T is the clutch pedal halfway down so that neither the high clutch is engaged nor the low band is tightened.
To start the vehicle, the driver would release the emergency brake and ease the left pedal to the floor. As the vehicle starts moving, the driver would pull the gas lever down to increase the speed. As the road speed increases, the driver would let the left pedal all the way up, shifting the transmission to its top gear.
To reverse, the driver would depress the center pedal towards the floor, starting the vehicle in a reverse direction. To stop, the driver would let the center lever return to the up position and ease the brake pedal down.


This what Google gave me:
On a Ford Model T, the transmission and engine are a single unit, sharing the same oil. The planetary transmission operates by clamping bands lined with friction material against drums.

Perplexity seems to be a bit more thorough but still not complete.

Better than a lot of folks who have driven T's for many years.

That said, I hate and despise all things AI.

Missing is an explanation of the planetary system & how gear changes work.
A planetary system requires a hold, which is low band on a T.

The explanation for how one works I’ve come to without having really torn into mine is something like 20 some odd hp goes in the one end and out the other end comes slightly less than that, some grinding noise, and metallic confetti of some sort.

Not a bad simple explanation really. Remember AI stands for artificial idiots

Matthews explanation is all we need. I loved it. Can I get permission use that statement the next time someone asks me how it works.

Makes a difference whether one wants to know how to work the pedals to shift the car or how the pedals do when pushed or released to cause the gears to shift.
Norm

It’s all yours, go for it.

Rather than artificial idiots, my sheep breeding experience included AI long before this latest acronym. AI is artificial insemination.

Allan from down under.

I haven't been called an "artificial idiot" yet, but there is still time. (How the Model T Transmission Works - youtube video by me.)
https://youtu.be/jsaRIrJX-NE

I would like to announce that after a great deal of tinkering with code, the Model T Transmission Simulator is working again!

https://www.fordmodelt.net/transmission-simulator.htm

A small disclaimer though, the simulator uses an outdated media format called Shockwave Flash and may contain errors. It's using some clever behind-the-scenes coding trickery to make the original simulator come to life - so please persevere with it!

Question. Did Henry Ford actually invent the Model T's transmission?

Mr. Henry Ford did it.

bobt wrote: ↑

Sat Mar 15, 2025 4:59 am

Question. Did Henry Ford actually invent the Model T's transmission?

The planetary transmission was not a new thing when the Model T came about. All the early Fords used it, as well as many other makes. I'm sure the patents shown above are for some unique features specific to the Model T. So, if your question was, "Did Henry Ford invent the planetary transmission?", I would argue the he did not. Did he, (and his team), design novel and unique differences in the use of the planetary transmission for the Model T Ford, I would say that yes, he did.

I a'm not trying to start an argument, but I was told that the only thing that Henry invented was the charcoal BRIQUETTE. He was most credited for improving the modern assembly line. He did assemble all the engineers who invented the model T's transmission but no one man was credited.

I agree with Jerry. Henry Ford was a talented farm kid and an excellent businessman. He developed the concepts and oversaw the details but he wasn't an engineer. One of his key engineers that joined Ford in 1905 was Jozsef Galamb and he worked in the backroom at the Piquette Plant with other engineers turning H.Fords' ideas into blueprints and patented projects. LIke most other successful businesses and corporate endeavors there is always a lot of hard working people behind the scenes that make things happen.

Has some good stuff https://www.modeltcentral.com/Model-T-F ... html#bands

This is one article. It used to have a really good interactive animation of the transmission gears
https://www.modeltcentral.com/transmiss ... ation.html
some of it below


Low Speed
When the driver wishes to move off (forwards), the emergency brake is released halfway (to allow the rear wheels to turn), but still preventing the clutch spring to clamp the discs together. (obviously you can't just "drop" the car into high gear as it would stall the engine - although this is physically possible
The driver pushes and holds the low speed pedal down whilst altering the engine speed to compensate. This clamps the low speed drum and gear still. Because there is a difference in gear teeth between the low speed gear and meshed triple gear teeth, the triple gears turn on their axis at a slower rate than the flywheel and in turn rotate the driven gear in the same direction as the flywheel also at a slower rate.
Because of the difference in gear size between the low speed drum gear and meshed low speed triple gear, the driven gear is forced in the same direction as the flywheel at the same slower rate. Remember the driven gear is locked to the brake drum and therefore turns the brake drum and driven plate (remember its bolted to the drum) and therefore the driveshaft at the same reduced rate.

High Speed Gear
when the driver wishes to engage high gear (direct drive), the emergency brake lever must be released fully forward (whilst the low pedal is either held halfway or fully depressed engaging low gear) so that it no longer prevents the clutch spring from compressing the clutch discs. As the car speed is increased, ready to shift to high gear, the driver momentarily lowers the engine revs and simultaneously releases the low gear pedal (and therefore the last resistance holding the clutch spring back), this allows the clutch spring to apply full pressure to the discs, clamping the small discs between the large discs. Now remember that the small discs are directly fixed to the disc drum and therefore transmission shaft and flywheel, and, the large discs are fixed to the brake drum and therefore driven plate. So the action of clampng the two together, provides a direct link as follows:

Most people see AI as OZ the all powerful Wizard. It is nothing more than an aggregate collector of source material across the internet, which runs the spectrum between fact and fiction. Garbage in, garbage out.

The Model T transmission simulator on modeltcentral.com no longer works.
I have re-engineered it on my own website so it works again

https://www.fordmodelt.net/transmission-simulator.htm

TRDxB2 wrote: ↑

Sat Mar 15, 2025 12:40 pm

Has some good stuff https://www.modeltcentral.com/Model-T-F ... html#bands

This is one article. It used to have a really good interactive animation of the transmission gears
https://www.modeltcentral.com/transmiss ... ation.html
some of it below


Low Speed
When the driver wishes to move off (forwards), the emergency brake is released halfway (to allow the rear wheels to turn), but still preventing the clutch spring to clamp the discs together. (obviously you can't just "drop" the car into high gear as it would stall the engine - although this is physically possible
The driver pushes and holds the low speed pedal down whilst altering the engine speed to compensate. This clamps the low speed drum and gear still. Because there is a difference in gear teeth between the low speed gear and meshed triple gear teeth, the triple gears turn on their axis at a slower rate than the flywheel and in turn rotate the driven gear in the same direction as the flywheel also at a slower rate.
Because of the difference in gear size between the low speed drum gear and meshed low speed triple gear, the driven gear is forced in the same direction as the flywheel at the same slower rate. Remember the driven gear is locked to the brake drum and therefore turns the brake drum and driven plate (remember its bolted to the drum) and therefore the driveshaft at the same reduced rate.

High Speed Gear
when the driver wishes to engage high gear (direct drive), the emergency brake lever must be released fully forward (whilst the low pedal is either held halfway or fully depressed engaging low gear) so that it no longer prevents the clutch spring from compressing the clutch discs. As the car speed is increased, ready to shift to high gear, the driver momentarily lowers the engine revs and simultaneously releases the low gear pedal (and therefore the last resistance holding the clutch spring back), this allows the clutch spring to apply full pressure to the discs, clamping the small discs between the large discs. Now remember that the small discs are directly fixed to the disc drum and therefore transmission shaft and flywheel, and, the large discs are fixed to the brake drum and therefore driven plate. So the action of clampng the two together, provides a direct link as follows: