Dana 70 missing tag ID

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Mar 16, 2010 | 01:45 PM

hairyboxnoogle

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Dana 70 missing tag ID

Alright, pulled the diff cover off and on the ring gear found some things, 10-27-78, date obviously, then it says Dana and a serial number, then past that, facing the other way, (upside down compared to the other numbers) 257, no period in it. looks more cast in than it does stamped, its an open diff. Would 257 be the gear ratio?.....

Edit: serial numbers are : Dana 34887 B3R85 41-11 then upside down 257

Mar 16, 2010 | 01:53 PM

fatdan460

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From: utica il

i highly doubt something that high would be in a d70 jack it up and count how many rotations of the pinion shaft it takes to make one full rotation of the tire, that should get you in the ballpark of what gear you've got, but get someone to help you turn the tires cause they need to turn the same amount at the same time.

Mar 16, 2010 | 02:05 PM

HillbillyDeluxe81

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From: Hattiesburg, MS

Right past the string of numbers that include the date code, there will be 2 sets of numbers, separated by a dash. For example, a 4.10 gear will read "41 - 10". That's the number of teeth on the ring and pinion. Divide the first number by the second, and that will tell you the gear ratio. 41/10=4.10. A ring gear that reads 46 - 13 would be a 3.54 ratio. Got it figured out now? Does it have a 2 piece carrier?

Mar 16, 2010 | 02:23 PM

fatdan460

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From: utica il

i believe you have 3.73's forgot about number stamp. i knew about dividing ring teeth by pinion teeth but unless its apart you can't count pinion teeth

Mar 16, 2010 | 02:38 PM

HillbillyDeluxe81

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From: Hattiesburg, MS

Fat Dan, did you read anything I just said??

Mar 16, 2010 | 02:47 PM

HillbillyDeluxe81

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From: Hattiesburg, MS

OK. Nevermind. I finally figured out where the "periods" were supposed to go. I understand what you were trying to say, now. You're correct. They are 3.73's.