F250 3.73 to 4.30 axle ratio
I have a 2017 F250 4x4 crew cab, 160" wheel base, 6.2l gas, 3.73 gear ratio. I am trying to see if having 4.30 axle ratio gears installed will make much difference regarding 5th wheel towing. I noti...
Forum Discussion
BenK wrote:
Mark the drive shaft or tape a length of string on the drive shaft
Roll the vehicle one tire valve rotation
Then count the number of sting wraps on the drive shaft, or have someone count the chaulk marks on the drive shaft
Whole turns is the first, whole number of the diff ration...3 turns...4 turns, etc equal 3.xx or 4.xx
Fraction of a string wrap will be the fractional portion of the diff ration...3/4 turn, then X.73, etc
Remember to remove the string
Got some folks yelling at me on another forum...guess they didn't remember to remove the string...
Or just look up the code on the door jam.
Really unless you are using that last bit of tow rating (ie: you aren't exceeding the tow rating with the 3.73), it won't make much difference. I think it's 6 speed transmission in 2017, so it will just pick a different gear and result in roughly the same overall gear ratio from crank shaft to wheel.
