Changing Rear Gears in a Ford F-150: Worth It?
Swapping lower gears into your rear end is an old school hot rod trick. But does it work on a new school Ford F-150?
In hot rodding’s glory days, swapping out your rear gears with something “lower” was a quick, cheap, and dirty way to improve performance. For mere pocket change and an afternoon, you could make your car or truck jump off the line that much quicker, maybe making the difference between a win and a loss at your local digs. But in this day and age of high-tech componentry, does that old trick still work on a newer Ford F-150? It’s a fair question, and one that Ford Truck Enthusiasts member King-bRanch recently presented right here in the forums.
“I recently purchased a 2013 Ford F-150 XLT 5.0 2wd that had some 265/60/18 tires. I swapped the wheels with some aluminum take offs from an ’18 STX 4×4 that has 275/65/18s on them. The tires are around 1 1/2” taller. My truck has 3:31 gears in it, which seemed fine with the original wheel and tire size. But I can feel a difference after the swap, and my mileage went down.
I do paintless dent repair for a Ford dealership and know the heavy line technician who does gear swaps regularly. So I can get the re-gear done for around 500 bucks including parts. Am I going to feel much difference going from 3:31s to 3:73s? For the price I can get this done for, I’m pretty sure I’m gonna do it.”
Needless to say, the responses to this question came hot and heavy. Including an excellent one from pdqford, who gets all scientific on us.
“Going from a 265/60/18 up to a 275/65/18 is going to reduce your engine RPMs by 5%. It will also increase the weight of each tire from 37# to 42#. Going from a 3:31 to a 3:73 will increase your engine RPMs by ~13%. Net effect of both changes will increase you engine RPMs by about 8%. So, say your truck was turning 1600 rpm at 60 mph. With both changes, your RPMs will jump up by about 125 rpm to 1725 rpm.”
Pretty much everyone supports the change. But while some recommend 3.73 gears, other recommend jumping up to a 4.10. Which makes the choice even harder.
“2018 Ford F-150 STX trucks come with 275 55 R20 wheels stock,” said ford390gashog. “I wouldn’t waste my money going to a 3.73. Yes, it will be noticeable. But I would spend the money and get 4.10 at a minimum. However, $500 for a gear swap is a good price.”
“I also have a 2013 Ford F-150 5.0,” adds EarlM. “I have not changed tire size, but went from 3.31 to 3.73. I did so to increase my towing performance. I must say, I really like the improvement, even when not towing. I did have issues getting my speedometer correct. But Hypertech fixed that for me.”
In the end, the OP went with a 3.73 upgrade. And by the sounds of things, it was the right choice.
“Got the 3.73 gears installed on Monday and I am very happy with the results. The truck now has its pep back the way it was before the wheel and tire swap. I ended up having to order the Superchips flashcal due to the speedo being so far off. We used the Ford IDS to reprogram for the gear and tire changes, but the tech said changing the gear ratio with it will not correct the speedo.
The truck seems to shift better now, at the correct speeds and throttle positions. Besides spending all the money for the gears, installation, and now the flashcal just for a simple wheel and tire change, I’m very happy with my decision.”
All’s well that ends well. But we still want to know – have you had a good/bad experience swapping gears in your Ford F-150? Head over here and tell us about it!