Changing from 3.73 to 4.10 gears
Hello all, After towing our new Reflection 320MKS from Eastern Iowa to Estes Park Colorado and back, I need more power for the hills. I have a 2015 F-250 with the 6.2 Liter engine. I have 3.73 years...
Forum Discussion
RCMAN46 wrote:
"If the same truck is expected to pull 35000 lbs down that same highway it can be determined that 440 HP can only pull the hill at about 52 mph. It would be desirable for the transmission to again be in 4th gear while the engine is running near 2800 rpm.
This truck will have a little smaller diameter tires and should have a 4.30 rear gear ratio."
Ok but lets assume I have enough horsepower go 60 mph or the hill is a little less grade. Then a 3.73 gear would be best at 2800 rpm and 4th gear.
Yes the 3.73 might be better for that particular hill, it is a matter of selecting the gear ratio that targets the typical use of the truck. If it is rare that you are pulling grades over 4% and often that you run empty up and down the highway you might want a 3.55 axle ratio to tow your 24000 lb rv. The odd time you hit a 6% grade you just let the transmission drop to third gear.
