The Ford Barn - View Single Post - 60 mph or 100 mph? 3-speed or 4-speed?

expavr · 09-03-2023, 04:37 PM

“Strange that 3 speed goes 100 and 4 speed goes 60?”

The 4 speed transmission is a heavy duty straight gear transmission (no synchromesh) that was used in large trucks or similar applications. The Rear Axle Gear Ratio associated with those transmission started at 4.86:1 and went up to 6.67:1 which effectively limited the top speed those vehicles could travel. The speed shift indications on the speedometer indicates that speedometer came from a truck or a vehicle that had a high numerical set of rear axle gears.

09-03-2023, 04:37 PM	#2
expavr Senior Member Join Date: May 2010 Location: Hansville, WA Posts: 777	Re: 60 mph or 100 mph? 3-speed or 4-speed? “Strange that 3 speed goes 100 and 4 speed goes 60?” The 4 speed transmission is a heavy duty straight gear transmission (no synchromesh) that was used in large trucks or similar applications. The Rear Axle Gear Ratio associated with those transmission started at 4.86:1 and went up to 6.67:1 which effectively limited the top speed those vehicles could travel. The speed shift indications on the speedometer indicates that speedometer came from a truck or a vehicle that had a high numerical set of rear axle gears.