Your comments on gear ratio

[Mykol]

I have a 99 1/2 CC 4X4 dually automatic with 3.73 gears. If I had the chance to change complete axles with an identical truck both with around 59k miles, would ya'll recommend changing for 4.10s? The reason I ask is because I can pull a 32' fifth wheel camper better at 75 than 65 or 70 with my 3.73s. It seems at 2000 rpm or lower, any hill pulls me down but I can better hold my speed if I am running 2200 to 2300 rpm. Any comments?

[straycat]

You could do that, but remember your best mileage is under 2000 rpm, so you may pull the hills better, but your mileage will suffer. I have the 4.10s in mine, and my mileage is not as good as I would like, even runing empty, and I would probably change to the 3.73s if I had some available at a good price.

Gord.

[MrJohnWayne]

The 4.10's will surely be better for pulling on the hills and all around but you are gonna lower fuel mileage. with my 4.10's running 75 i'm at roughly 2500 rpm's. With my mods my fuel mileage isnt bad but still isnt great.

[sea71]

Could be that you are more into the power band at that speed than at 60-65. At the slower speed you may be just under where the most torque and power is, therefore seeming to bog a little.

[sirnunya]

I would try running with OD off when you're towing before I went to swapping out axles

[steph38]

Don't want to hijack the tread but i have the same problem with my truck i run with toyo open country 285 70r17 if i put 4.10 gear what rpm i should run at 60mph for now i have to run with the od off and keep it at 55 @2200rpm