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Gentlemen,
I am getting ready to sell (or more likely give away !) the original rear end that came in my 51 F1. The limited shop manual, books etc. that I have lists a 3.92 as standard and a 4.27 as the option. So I set about to figure which one I have. By the way, no glove box door or any other codes on the truck anywhere.
So my understanding to determine the ratio is;
Block one side from turning
Rotate the free side 10x
Count the revolutions of the driveshaft. (I got about 17.5 on many tries.)
Double the 17.5 to get 35 indicating a gear ratio of 3.5 ! This does not seem right to me ? Maybe I did something wrong, however, I have used this method on other rear ends and came up with the correct answer. I have no indication that the rear end was swapped out but that is certainly possible.
Open to any thoughts on this. Will try to include a picture.
Gentlemen,
I am getting ready to sell (or more likely give away !) the original rear end that came in my 51 F1. The limited shop manual, books etc. that I have lists a 3.92 as standard and a 4.27 as the option. So I set about to figure which one I have. By the way, no glove box door or any other codes on the truck anywhere.
So my understanding to determine the ratio is;
Block one side from turning
Rotate the free side 10x
Count the revolutions of the driveshaft. (I got about 17.5 on many tries.)
Double the 17.5 to get 35 indicating a gear ratio of 3.5 ! This does not seem right to me ? Maybe I did something wrong, however, I have used this method on other rear ends and came up with the correct answer. I have no indication that the rear end was swapped out but that is certainly possible.
Open to any thoughts on this. Will try to include a picture.
It is unanimous! I have an approx. 3.5 rear gear. Both of the methods listed above, and my earlier method, all say it is a 3.5. (No identifying tags on the rear end.)
So, now that I am the proud owner of such rare and exotic hardware - Will this allow me to retire in luxury ?
You probably have a DANA 44 with a 46/13 3.54 ratio. This was not a stock Ford ratio, but DANA 44s have been used everywhere for years and years and have much more ratios available than Ford ever used factory.
Count yourself lucky! It might be worth popping the cover off and looking for stamped tooth counts on the R&P for final verification. Unless someone has already converted to a later 3.54, it could be a 3.73, especially if your truck is an early '51.
Just to clarify what Ross said when both wheels are off the ground BOTH tires need to be turned in unison for one revolution while counting the pinon revolutions. It would be hard to diferentiate between 3.5 and 3.7 gears without putting marks of some kind on both tires and the pinion. Like stated, if your giving it away you might as well pull the cover to verify your need learned skill.
It is unanimous! I have an approx. 3.5 rear gear. Both of the methods listed above, and my earlier method, all say it is a 3.5. (No identifying tags on the rear end.)
So, now that I am the proud owner of such rare and exotic hardware - Will this allow me to retire in luxury ?
03-08-2024, 05:39 PM
