11-22-2019, 01:00 PM | #1 |
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gear ratio
An acquaintance is trying to give me a differential for my 1950 Ford. It has 15 teeth on the pinion and 42 on the ring gear.
By my calculations that is a 2.80 ratio. Obviously I can't use it but I have never heard of that ratio. What the heck is it? |
11-22-2019, 01:06 PM | #2 |
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Re: gear ratio
According to the numbers 2.80 is indicated. That ratio varies according to the engine type and transmission used. It can also vary as to the location, as hilly places require additional power. This is true to both cars and trucks.
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11-22-2019, 01:22 PM | #3 |
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Re: gear ratio
You didn't say specifically, but is it even for an early '50's Ford? They never offered that ratio or even anything close to it. I can't believe that the after-market offered that ratio either, but never say never.
Last edited by tubman; 11-22-2019 at 02:04 PM. |
11-22-2019, 01:55 PM | #4 |
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Re: gear ratio
A ratio in that range is not unusual for later automatic transmission cars. I had a 2.79 ratio 9" rear axle/302/c4 in my '40. I put many miles on it going all over the southeast.
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11-22-2019, 02:51 PM | #5 |
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Re: gear ratio
Sounds like your friend is trying to offer you a later model 8" rear end. Is it just the 3'rd member or the axle assy.? Numerically most of the early 50's Fords had 4.11's or somewhere around 3.89's. I do know first hand that nothing numerically 3.55 down will not replace a housing that occupied the 4.11 or 3.89 gears in the 1950 housing. If you are going to retain the 49-56 axle housing you would need to use a 54-56 housing that had 3.55 gears or lower number. Reason being the ring gear hits the rear of the housing when trying to install the later highway gears. You will also find that the axle splines changed somewhere around 54-55. IMO you may be better off looking for a complete 8" from an early Mustang,Maverick or Fairlane. Your housing should measure close to 53" axle flange to flange. Same as 57-59 Ford car or wagon.
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11-22-2019, 09:08 PM | #6 |
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Re: gear ratio
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Tommy |
11-22-2019, 09:36 PM | #7 |
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Re: gear ratio
I agree with Sid. 50's Ford rear axles had a much lower ratio (higher numerically) . The ratio you mentioned didn't come out until later with the 8 inch rear of the 60's and the center section (and gears) are not compatible with the earlier housings..
If you are looking for a better ratio, the 52 to 56 automatic rears had around a 3.31 ratio. Not sure if the 52-56 center sections fit in the 50 housing.
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11-23-2019, 12:59 AM | #8 |
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Re: gear ratio
[QUOTE=Sid;1824068]Sounds like your friend is trying to offer you a later model 8" rear end. Is it just the 3'rd member or the axle assy.? Numerically most of the early 50's Fords had 4.11's or somewhere around 3.89's. I do know first hand that nothing numerically 3.55 down will not replace a housing that occupied the 4.11 or 3.89 gears in the 1950 housing. If you are going to retain the 49-56 axle housing you would need to use a 54-56 housing that had 3.55 gears or lower number. Reason being the ring gear hits the rear of the housing when trying to install the later highway gears. You will also find that the axle splines changed somewhere around 54-55. IMO you may be better off looking for a complete 8" from an early Mustang,Maverick or Fairlane. Your housing should measure close to 53" axle flange to flange. Same as 57-59 Ford car or wagon.[/QUOT
Referring to the work you did on my '50 Sid? Still working good! Thank you my friend............ |
11-23-2019, 06:51 AM | #9 | |
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Re: gear ratio
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11-23-2019, 09:14 AM | #10 |
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Re: gear ratio
I have heard that 3.31 gears were available in Fordomatic cars in 1951. There is a gentleman on here occasionally who claims to have one and to have seen another. My '51 no O/D V8 came originally with 3.54's, so it may be possible.
Take it for what it's worth. |
11-23-2019, 10:52 AM | #11 |
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Re: gear ratio
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11-23-2019, 11:12 AM | #12 |
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Re: gear ratio
I am talking about the naked housing. No drums or axles. Measuring the housing flange to flange. I do know 50-59 are the same width measuring just the housing but the perches on the 57-57 are just a tad wider by about 1/2". I think that overall width they should be very close. I wasn't clear on that earlier.
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11-23-2019, 09:20 PM | #13 |
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Re: gear ratio
Thanks, friends. I'm sure this will not work in my '50. I just wondered what car had a gearing that high. I would have to get a push to take off even if it did fit. But I will tell the owner of the rear end that it is for a much later 8" Ford. I appreciate all your responses.
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11-23-2019, 10:06 PM | #14 |
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Re: gear ratio
I'm a little confused though. As I remember 2.79 ford 8" was a 14-39 ring pinion. I just don't recall a 2.80 ratio in a ford car in a 8" or a 9". Unless it might be from a Pinto or a Bobcat or some other compact.
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11-23-2019, 11:00 PM | #15 | |
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Re: gear ratio
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