edit............

 

The housings are the same 09-up. If you order Gears for a 2010 or older you will be able to get away with running the older style bearings as well.

 

What computer reflashes will need to be done after the gear change?

 

None, on a Ford, if your only change is to the ring gear and pinion (axle ratio). I don't know about other brands of pickups.

On a Ford, the speedometer, odometer, trip meter, and trip computer (including MPG computation) are not affected by a change in axle ratio. Those are all controlled by the tire revs/mile parameter stored in the ABS module and used by the PCM (main computer). So a change in tire revs/mile (i.e., changing tire size) will affect the speedometer, odometer, trip meter, and trip computer. But a change in axle ratio will not affect the tire revs/mile, so no change required to the computer programming.

 

I got this from 4wheel parts today. Just thought I'd share the information as it comes to me.

David,
I just checked with all the gear manufacturers what we sell, and
still no-one has a bearing kit that works for the 2011 and newer F-150 axle
housing. They are having to design ring and pinions specifically for this
housing to accept the old bearings due to Fords change of the inner pinion
bearing design on the '11 and up trucks. I will continue to check for you
and let you know when something is available. I appreciate your patience,
and look forward to building your truck as soon as parts are attainable.

 

You will need a programer.
My speedo was way off with 35's and 4.56's. 120kph when I was doing 100 with GPS.

With Fords IDS scan tool I was only able to reprogram to a 3.73 axle ratio, so I programed it for 3.73's, and 30" tires. This put me to 105kph when doing 100 with GPS.

I then Purchased a used Hypertech programer and It got my speedo bang on.

 

What kind of rpms are you turning at those speeds?

 

Not because of the gear change. Your speedo was way off because of the tall tires, not because of the 4.56 axle ratio.

The Ford dealer's diagnostic system (computer) can change the tire size only to a size that's available on your year/model Ford. If your tires are not a size that was an option on your Ford, then yes, you need a programmer/tuner that can change the revs/mile parameter in the ABS module.

Way back when, the Ford diagnostic system allowed you to change the revs/mile parameter in the ABS module. So you could fine-tune the speedo to be very accurate. I did that on my '99.5 F-250 and got it down to 99.7 miles on the trip meter for an actual 100 miles per the interstate highway mile markers. But a few years ago the Ford system developers changed the program to use tire size instead of revs/mile, so now you have to have a tire size that's in the diagnostic system in order to get an accurate speedo. The computer converts tire size to revs/mile, and actually stores the revs/mile parameter in the ABS module. So if a programmer/tuner or computer program can access the ABS module you can still correct the speedo (and trip meter, odometer and trip computer) to show accurate miles, MPH, and MPG.

 

Trust me the axle ratio does change the speedo reading. I am a Ford tech aswell, and I have played with the programable perameter option on the IDS before. You can chose to adjust tire size between tire sizes that were avalible on the f150, or rev/mile. But there is a limit to the sizes that you can select. There was 315/70 17 on the list of sizes, but it would not let me select it. The axle ratios avalible were 3.31, 3.55, 3.73. I was not able to get my speedo bang on when I went up in tire size because it would only let me select a 33" tall tire. But when changing the axle ratio to 3.31, and playing with my rev/mile I was able to get my speedo to match the GPS.

Before 1450rpm at 62mph (315/70 17s and 3.55 gears)
After 1950rpm at 62mph (315/70 17s and 4.56 gears)