Front and Rear Diff I.D.

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Oct 8, 2003 | 09:51 PM

musty24

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Front and Rear Diff I.D.

I was curious about what type my diffs are. I have a 77 f-250. I have recently been introduced to the wild world of 'wheelin' and have been eagerly building a truck of my own

. It has a 6" susp lift, and 2" body. Anyway, I got the numbers off the front and rear diff covers and they are as follows:
Front: 4 09 D91A AZA
610069-4
Rear: 4 10 D71A ACB
603683 11

If someone could identify these for me, I would greatly appreciate it. I hope these are all and the correct numbers needed.

Last edited by musty24; Oct 8, 2003 at 10:11 PM.

Oct 9, 2003 | 05:40 PM

JeremyH

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It sounds like you have a 61 front and 60 rear.....although I thought that 61's were only a rear axle. Hummmm....

Oct 9, 2003 | 07:10 PM

bubbaf250

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Assuming the tags are original and the differentials have not been changed...

The front is a Dana 44 with 4.09:1 ratio and standard (open) differential.

The rear tag numbers show a 4.10:1 ratio standard (open) differential, with a Ford part number that was originally for a 1977 truck (D71A).

Unfortunately, the Dana BOM number you gave for the rear axle (603683) shows up as a Dana 44 front axle for a '78-'79 Jeep Wagoneer/Cherokee, with no -11 suffix option. Check that number again.

Oct 9, 2003 | 08:01 PM

musty24

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okay what about this:
603883

these number have years of dirt, oil and paint over the top of them that makes them slightly difficult to read. I will do some more scraping to see what comes up

Oct 9, 2003 | 10:52 PM

JeremyH

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Bubba, where are you looking all of this info up?

Oct 10, 2003 | 11:19 AM

bubbaf250

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The number 603883 doesn't show up as a valid BOM number. It could be old enough to be an obsolete BOM, but those are usually identified anyway and just noted as obsolete.

You guys can look up Dana BOM numbers on the Dana website at:

http://www2.dana.com/Expert/

Oct 10, 2003 | 05:23 PM

RRMike

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From: Roseburg OR.

If they are original the front should be a low pinion D44 HD and the rear a D60. The tags seem to indicate 4.09 and 4.10 ratios. I would assume these are correct if they haven't been removed.