What do I have...Dana 44 or GM 10 Bolt

CheemsK1500

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My ‘75 GMC K25 has what is called a Dana 44 HD, 4.10 ratio front axle, but I’m not sure what makes it an HD. It may just be whatever is changed at the hub area to allow for the 8 lug wheels.
The brake rotors and calipers are larger on the HD as well.
 

Kurnacopia

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My ‘75 GMC K25 has what is called a Dana 44 HD, 4.10 ratio front axle, but I’m not sure what makes it an HD. It may just be whatever is changed at the hub area to allow for the 8 lug wheels.
How do I know if I have a Dana 44 HD?


The Dana 44HD has a larger knuckle bearings and axle u-joints and it can be easily identified by the 12 bolt knuckle ball seal.

So says Google......
 

rpcraft

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My ‘75 GMC K25 has what is called a Dana 44 HD, 4.10 ratio front axle, but I’m not sure what makes it an HD. It may just be whatever is changed at the hub area to allow for the 8 lug wheels.
It's just everything outboard of the knuckle pretty much without looking at a parts book from what I can remember. Obviously the hub is different (being 8 lug) and I think the hub itself has bigger bearings on early years (and maybe that is what made it HD on your truck) but by 77 they were all the small bearing setups from what I recall. (small meaning the measurement of their OD)

I've heard theory that the only major difference was smaller bearings had thicker races with the same ID on the bearing (since the spindle shafts are always the same sizes), but again, never had parts side by side to measure and (and look up the bearing numbers) so I have never seen or had to order big bearing parts. I also have come to believe that if they did do that then that is probably why I've never seen a part # for big bearing, and if you were to look up your parts it would probably cross convert them to the bearing sets that are current and technically the "small bearings". Alas, these are the dark thoughts that keep me awake at night (FML).

For certain there is a different backing plate that moves the brake caliper some but have never had a k20 and k10 rotor to compare the diameter and thickness and where the caliper sits in relation to it all but I know they use the same calipers and pads so not sure if it is just moved out for hub clearance or maybe (in or out in relation to the wheel). The locking hubs should fit across the board though.
 

rpcraft

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