60 mph or 100 mph? 3-speed or 4-speed?

H

htc

Member
Hello,

I am restoring the gauge clusters used in 1940-1947 trucks.
I did already start some discussions on this (https://www.fordbarn.com/forum/showthread.php?t=323279&highlight=clusters) but still not yet everything is clear to me:

The 60 mph speedometers have gear shift indications and as such seem to be used in cars with a 4 speed transmission.

The 100 mph speedometers do not have the indications. Are these for trucks with a three speed transmission?

Is the 3 or 4 speed transmission linked to the engine?

Not having a Ford truck it is all very fuzzy for me.

I do have all different gauge clusters however (Waltham, Stewart Warner and King Seeley) but I would like to know where they were used.

Greetings

Hans

PS. And yes, another question: which transmissions were the most popular? Strange that 3 speed goes 100 and 4 speed goes 60?
 
Last edited:
“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.
 
And I will try to answer some questions too. I don't think the six or eight cylinder engine had too much to do with the transmisson type. I have seen both with both. The load capacity of the truck itself had more to do with the transmission than the engine it was coupled too, There were 3 basic truck configurations in the '42-'47 series. The commercial which was a 114" wheelbase and most often sold as a pickup or panel truck. There were some stakebeds as well. I am pretty sure the 4 speed straight cut gearbox (T-9)was available for this size, but I have not seen one. The 3 speed was the normal trans for this class of truck and the axle ratio would have been in the low 4's or high 3's. Next was the 'tonner' with 122" wb and the vast majority used the T-9 as well. If the HD 3 speed was available, some may have had that option. The Other, larger trucks were 1 1/2 ton or 2 ton available in a two wheel bases. 131" and 157" (without looking it up). These would all have had the T-9. For your business I would say that the 1/2 tons are the most sought after and most restored. So, my business advice is heavy on the 100 mph speedometers and you won't get as much demand for the 60 mph.
 
all the available transmissions are 1 to 1 in high gear, so top speed is determined by the rear axle ratio
 
Hello expavr, GB SISSON and cas3,

What a wealth of information!
Exactly the answers I was looking for (and much more).

Thanks a lot! I appreciate.

Greetings
Hans
 
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