ratio stamping on the differtental housing

[Big Al]

Hi
i can',find the stamping on the differentalthat has the gear ratio. Where should i look for it? Thank you.

Big al

 

[Fred A]

Since most rear axle ratios were 9/34 in the Model A era, have seen very few stamped on the banjo as is the case in the later V8 era. I suspect that those I've seen were stamped after the fact to identify them among those of other axles. I have those gears rangeing from 11/36 to 9/41 and would certainly stamp the web of those banjos to distinguish them. There are many methods to determine the actual ratio but I'm too lazy to describe them. Good Luck: Fred A

 

[Ron in Quincy]

To my knowledge the rear banjo on Model a passenger cars was not marked with the gear ratio ? The speedometer drive gear, if not changed, identifies the rear end ratio.

Early 28's had a rear end ratio of 3.70; used a speedomer drive gear marked 10-37; this drive gear had 18 teeth.
In late 28 a 3.54 rear end ratio was available for Roadsters; it also used a 18 tooth drive gear.
Also in late 28 the ratio was changed to 3.78, used a speedometer drive gear marked 9-34; this drive gear had 19 teeth.

There was also a low ratio rear end available for light trucks 4.11; this ratio used a speedometer drive gear marked 9-37; it had 21 teeth on the gear

As an example, the 9-34 = 9 teeth on the pinion gear, and 34 teeth on the ring gear.

I believe the later speedometer drive gear housings were marked with the number of teeth rather than the ratio; such as 19.

Ron