Axle Gear Ratio

[MarknessMonster]

There's been a lot of discussion about the carriers and what aftermarket gear ratios are compatible with the stock M715 axles, but the information request is usually for a lower ratio for higher road speeds. I'm interested in something different. There are many times where I've wished for a lower gear. When in 4-low, I'd like to get to a creep when experiencing rough or deep terrain. When I use the term "creep", I mean that the truck tires rotate when I climb out of the drivers seat to help push.

What gear ratios will fit that are higher numerically than 5.87?

[Hammer]

Doubler transfercase.
Or an Atlas 4 speed transfercase.
Imagine your tcase options being, 1:1, 2.72:1,5.xx:1 AND 10.x:1 !!!
Granny transmission of 6.xx, tcase of 10.x:1, and axles of 5.87:1.
you do the math...

[Hammer]

Oh, as for the axles, the Dana 60/70 ratios go a bit further, but you start dropping off in pinion strength, etc.
Doubler tcase setups would be a LOT cheaper in the long run, offer more gear choices, and a much lower overall ratio.

[MarknessMonster]

Thanks Hammer. That is certainly the correct solution. I didn't think of a doubler yesterday when I was "crawling" over some newly excavated and frozen earth berms. My mind just thought about the height of my tires and the "drop" in the advantageous 5.87 ratio, since I couldn't get to a nice low creep in the big bumpy stuff without riding on the clutch. Plus, I have no experience with doubler transfercases.

A doubler would allow me to retain good highway manners that the 39" tires and NV4500 currently provides.

[brute4c]

I have seen 6.17 and 7.17 ratios for the D70...dont know if both are available any more OR if these fit the 60....

[Hammer]

I have seen 6.17 and 7.17 ratios for the D70...dont know if both are available any more OR if these fit the 60....

Normally, yes.
But I don't know if they will fit the ones in OUR axles.

[brute4c]

That is true too...they have been made for the D70...but not necassarily OUR D70...