1st post. Round eye square guy in NE Texas.

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Mujiir

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Get in there and clean up around the pumpkins you can Identify exactly what you have so you can get the right parts you need.
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Not sure if it's 44 8, or 44 81, 44 B... 8 lug HD with 6 lug spindles...? Got a guess?
 

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Mujiir

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More information... Dana 44-8F (BOM# on the tube) -> 610079-7 3 12 9 7BF And a ratio tag for 3.73 to 1 gearing? I don't know what the 41-11 means either.

I found this on the online AI site:
  • The axle Bill of Materials (BOM) number 610079-7 corresponds to a 1978–1979 GM Dana 44 front axle with a 3.07 gear ratio. It is specifically found in 1/2-ton 4x4 trucks, which includes your 1979 GMC Royal Sierra.

    Axle specifications
    • BOM Number: 610079-7
    • Axle Type:
      Dana 44 front axle
    • Vehicle Application: 1978–1979 GM 1/2-ton 4x4 trucks, including the 1979 GMC Royal Sierra
    • Knuckle Style: Open knuckle
    • Differential: Standard open carrier (for 3.07 ratio)
    • Gear Ratio: 3.07:1
    • Axle Shaft Spline Count: 30-spline inner axle shafts
    • Wheel Bolt Pattern: 6-lug, 5.5-inch pattern
    • Brakes: Standard disc brakes



  • Important notes on decoding
    The full axle tag provides additional details:
    • 3 12 9 7BF: This is a production code. The "3" may indicate a production line or variation. The "12 9 7BF" generally refers to the date of manufacture. It decodes to the 129th day of 1977.
    • Reading the BOM number: The Bill of Materials (BOM) number is a critical code used by Dana to identify the exact parts used in an axle assembly, including the gear ratio, type of differential, and component parts. Traditional BOMs start with a "60" or "61", even if those digits are sometimes dropped on the tag itself. The "610079-7" clearly identifies the axle.




  • Not sure about the 3.07 ratio. Other AI searches said this axle was off a 3/4-ton truck, and that search had the correct 3.73 ratio shown on my ratio tag... It seems that even definitive answers are subject to question.
 

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Last edited:

hoagster

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Good job decoding your axle, I'm impressed you got farther than I did on mine! Like I said Denny's is a good site because they the exploded parts diagram. You can use it for a reference. All the parts are available at many vendors.
 

Mujiir

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bucket

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Not sure about the 3.07 ratio. Other AI searches said this axle was off a 3/4-ton truck, and that search had the correct 3.73 ratio shown on my ratio tag... It seems that even definitive answers are subject to question.

I would never call AI searches a "definitive answer".

If you pull that cover, I'll bet you find a 3.73 gearset in there, just like the tag says. But if you do, be sure to put that ratio tag back on there because in my experience, most people don't.
 

Mujiir

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400 cid
Now we went and did it...
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hoagster

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No turning back now! You might as well go the whole way like I did!! Just kidding it's a lot of work putting it back together believe me.
 
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