2014 and up gear swap

KarL45 said:

Just curious, how are you liking the 4.56 gears? Did they seem to get you back to normal on power, accel, and fuel mileage? Also, have you changed out gear lube? It was required on mine at 500 miles to maintain a warranty. So far, there only seems to be 3 or 4 that have changed and think I may be the only one to have the OEM 18" wheels and tires. Sure that going to 35's or 37's will make things a lot different.

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SouthTexan said:

You do not have to run it to get the rpm at certain speed and gear.



The formula is as follows: (Axle Ratio x Vehicle Speed x Transmission Ratio x 336.13) / Tire Diameter = Engine RPM



66RFE ratios

1st 3.231:1

2nd 1.837:1

3rd 1.410:1

4th 1.000:1

5th 0.816:1

6th 0.625:1



Try to be as precise as you can on the tire size because even a .25 inch can make a difference. This is also a good way to verify if your speedo is correct too.

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NewBlackDak said:

Yeh, but I'm lazy.


Sent from my iPhone using Tapatalk

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