MTFCA Forum

Some years ago, a fellow club member had a T with a rebuilt differential that screamed like a fire truck siren. Well while flicking through some Canadian service bulletins, I learnt that in mid 1923 that Canadian T's had changed the diff gears, it seems that mixing with older ones was not a good idea, parts books also confirm the change. but I don't see them in the USA books. Did it happen to the US T's as well?

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It is never a good idea to mix and match ring and pinion gears. Always buy them as a set. When a differential is noisy, it is usually because of worn gears, however if it is a high pitched scream like a fire siren, the pinion gear is not shimmed correctly. When I had my differential apart and putting it back together, I took care to try different shims to get the gears to mesh properly. An old farmers trick is to take a strip of paper as wide as the gears and turn the gears drawing the paper through them. If the paper is all chewed up, the gears are too tight. If the paper comes through intact, the gears are meshed properly and will run just fine.

Good advice Harvey but not my point or question, mixing gears of different pitch is a no-no at any time, question is, did USA Ford use the change from 1923?

Quick answer, no.

I have read of the Canadian gear change, but never saw anything explaining the exact difference. It would also mean that mixing some Canadian gears with USA gears would likely be problematical.

Frank, did a quick check in the Encyclopedia documentation section, this might relate to the timing of a USA differential gear change: Jan 24, 1920 Acc. 575, Box 12- "Ten tooth pinion to be used with T-12B ring gear. T-12 48-tooth ring gear obsoleted. Old T-16, 12 tooth pinion, obsoleted."

I wonder if the change was to the pressure angle, from 14.5° to 20°?

I wonder why the picture above has the pinion facing the wrong way?

Original Smith wrote: ↑

Tue Jul 09, 2024 10:42 am

I wonder why the picture above has the pinion facing the wrong way?

I'd guess that it's because the identification dot, referred to in the text, is located there. What good would it do the depict it the "right way" and not show the dot?