Hello,

I've owned my F150 for about 4 months now and tow regularly with it, and have found the 3.31 rear end gear ratio paired with the 5.0L is kinda lacking with the hills we have here in Eastern Pennsylvania. Has anyone done a gear set swap in these trucks? Any recommendations for a company that sells a kit?

Another thing is what gear ratio should I go to? Stage 3 offers a 4.11 gear ratio, but I feel that that would be a little too low, 3.73 would probably be the overall sweet spot, and another thing I would like to do is retain the electronic locker.

Thanks in advance.

 

What size tires do you have, and are you thinking about getting bigger ones?

 

The tires that are currently on it are 275/65/R18 if I remember correctly, though I can't quite remember.

Edit: And no, no plan to go to a bigger tire size.

 

The biggest reason i want to change gear ratios is to improve towing, there's a couple hills in the immediate vicinity of me that if I'm loaded with about 5,000 lbs, the truck is in 1st or 2nd gear turning around 3-4000 RPM.

 

Your tires are 32.1” tall. 32.1 x .12 = 3.85. The factory usually rounds up, but lately they have been going way up to your 3.31s to get a higher fuel economy rating at highway speeds. In my opinion, all 5.0s should have come with 3.73s at a minimum.

Given the above simple formula, you could go with 3.73s, but if I was investing in the expense of a gear change I would go with 4.10s. You will get better performance and mileage when towing and in town. Empty on the highway over 60-65 your mileage will take a slight hit. There’s another thread on here that’s relatively recent where a guy went to 4.56 with his 5.0 and he is very happy.

 

The power band for that engine is at pretty high RPM compared to some other truck engines. Changing the gears doesn't change that. That engine is happy to run at 3000-400 for hours, don't sweat it is my advice.

 

Do you have a link to that post with the fella that did the gear swap?

And I never quite understood forsaking better towing capabilities for the sake of a mile or two better MPG, if the increase in MPG with 3.31 is even that good. I’ll probably end up going with 4.10’s and call it good, because the truck just dies on the hills!

 

Here’s a link to that thread

https://www.ford-trucks.com/forums/1...0-and-35s.html

 

Exactly. A few hundred extra RPMs in the otherwise same exact scenario isn’t changing much. Seems to be a common question around F150 forums lately. Gears aren’t a magic cure for not enough mass on a tow vehicle.

In the real world, Force = Mass x Acceleration

Either get a truck with more caboose that can overcome basically pulling its own weight uphill or get an engine that doesn’t need those kinda revs to get up to speed, like a 6.2 Super Duty. The 5.0 is fine revving like that, though.

 

Engines that are designed to rev, should be allowed to rev, or you shouldn't buy them. If you want lower RPM, get the Ecoboost or a diesel.

Lower gearing Can help the truck feel more peppy, but you aren't lowering your RPM any.

 

A lower gear ratio actually raises the RPMs in any given gear, which allows an engine like a 5.0 to operate in its sweet spot more.

 

^^^^^This exactly^^^^^ I'm still toying with changing my gears to 3.73 from the 3.31's that it came with. With the lower gear set the 5.0 will get into it's sweet spot a heck of a lot faster.

And to the OP you can keep the e-locker by just changing the ring and pinion. The gear set isn't all that expensive. It's finding a competent mechanic that is VERY experienced in gear setup that won't charge you an arm and a leg. I have never setup a gear set so DIY is out.

If anyone knows of such a mechanic in the north Dallas area, please let me know.

 

Having the proper tools, work place and time any more is the big factor for changing gear sets. Youtube will walk a person right through on the step by step process of just about anything.

 

You tube is full of wannabe's....... I have the space and can make the time. Most likely have all the tools needed as well. I was a line mechanic way back in the 70's at Dub Shaw Ford in Ft. Worth.

 

I agree with you on the wannabe’s;......there are a whole bunch of them that are way too impressed with the sound of their own voice! but one needs to sort thru the BS themselves.
I have set up a few differentials in my day also, just for myself, and had sucess. I.E. didn’t have any differential problems after the job was done.