Huge shout-out to Joe Rankin at Randy's Ring & Pinion. He gave me great info about how to swap out my rear 3.73 for a 4.30. (Thanks, Joe!).

But he cautioned that since Ford didn't factory sell the 4.30 on my E-350, that my mechanic may have trouble recalibrating the computer to match the new gearing.

Does anyone know if it's been done? Or if I'll have trouble with this??

 

Has anyone with a '12 or '13 E-350 done a rear diff swap? My mechanic is strongly suggesting that I speak with someone who's actually done what I've done before I do what I want to do...

He's scaring me with stories of malfunctioning ABS and TC systems because of the new gearing.

Isn't there anyone out there who's done this on a late-model E-Series Van??

 

Well if the rear end has a similar setup in it to the 8.8 rear (as regards the speed sensor) you need do nothing as the sensor ring is mounted to the ring gear and is unaffected by the gear change. In other words, the sensor ring turns at the same speed as the axle, not the driveshaft or pinion shaft. Only a change in tire diameter would affect the calibration.

 

I know that Ford techs are only allowed to recalibrate down to a 4.10. Which is a moot point because you will be hard pressed to find a Ford tech that knows how to do it in the first place. I have never found one.

 

I swapped a 2010 4.6l E-150 special ordered with a 3.73 back to the factory 4.10, no recalibration, no problems. As mentioned, the wheel speed sensors are at the wheels and unrelated to whatever you mess with in the diff / transmission. As long as it has RSC, the rear wheel speed sensors are at each hub rather than in the pumpkin, so whatever you do there doesn't affect the speedo. I hope you're towing a yacht through the Rockies or something similar to want that gearing though. I'm guessing you've got a 5.4L or better which at 4.10 would be a towing machine and at 4.30 would be a stump puller.... But whatever floats your boat, good luck.

-D