Anyone running 38" tires and 4.30 gears?

The Butcher · Jan 27, 2015

Since they don't seem to make a 4.10 ratio for the 14-15 model year trucks it looks like I'll have to jump to a 4.30 ratio. Anyone on here running 38s and 4.30 gears? I know a couple of guys are running them with 37s and seem to love them (per the threads I have searched and read), but I'm just wondering how they do up in the 75-80MPH range. Per the calculators I'll be spinning about 250 RPM higher at 80MPH than I would with the stock tires/gears. Wasn't sure if that would make a appreciable difference in gas mileage, noise, etc. I realize my gas mileage will be bad (currently running 37s on 3.55 ratio), so that isn't a huge factor. Just curious on how people with 4.30 gears like them. I do tow a couple of times a month, and getting that power back would be nice, but 95% of the driving is freeway/city driving back and forth to work. I don't see any point in doing a whole gear swap to a 3.73 which is the only option between the 3.55 factory ratio and the 4.30. Thanks for any input.

Randy_270 · Jan 27, 2015

Did Ford change anything in the axle for the 14-15s from the 11-13s?? I know Nitro Gear and Axle has 4.10 gears for the 2011+ 37 spline rear axles.

http://www.nitro-gear.com/news/2013...-quality-410-430-ring-pinions-for-the-20.html

Tom@BigTimeKustomz · Jan 27, 2015

I want to say Jared @River City Diesel re-geared his Platinum, but I could be wrong.

Trevor008 · Jan 27, 2015

Ford has factory 4.10 gears you can order. I went with 4.30's(still not installed) but I could have went 4.10 also. Check out Sunset Ford, that's who I got mine from

Trevor008 · Jan 27, 2015

Whoops... SunRISE no sunset lol

The Butcher · Jan 27, 2015

No one seems to offer 4.10 for the 2015. Ford doesn't (checked Sunrise and a local dealer), called West Coast and they didn't have any applications from their vendors, and same with 4WP. Not sure if it changed from 11-13 to 14-15, and the dealers weren't able to tell either. Have a friend that is a Ford engineer who is looking into from that end. He said some of the brake stuff changed, but shouldn't have affected the gears. He doesn't have any definitive answers yet though.

Sunrise has quoted me gears, and they have a great price. Will likely go with 4.30s from them, but wanted to get some feedback from anyone that might be running that set up with 38s. Thanks.

The Butcher · Jan 27, 2015

Tom@bigtimekustomz said:
I want to say Jared @River City Diesel re-geared his Platinum, but I could be wrong.

Yes, I believe he did. Seemed to rave about it in other threads. He's running 37s I think.

Inline6359 · Jan 28, 2015

Did you ask them if the 430 gears for your 2015 was the same part number as the earlier trucks?

The Butcher · Jan 29, 2015

Inline6359 said:
Did you ask them if the 430 gears for your 2015 was the same part number as the earlier trucks?

That's a good question...one I did not ask. I will check into that and see...

The Butcher · Jan 30, 2015

Just for future reference in case someone else runs into this before there is a solution:

They changed the spline count on the pinion gear for the 14-15 trucks. Went up to a 38 spline (if I remember correctly). So, as of today there is no aftermarket solution. OE gears only, and it's either 3.73 or 4.30. Nothing in between.

BBottoms · Jan 31, 2015

Couldn't you use gears with the lower spline pinion and just swap out the pinion yoke for the older style or is the pinion shaft/bearing/housing larger?

The Butcher · Jan 31, 2015

BBottoms said:
Couldn't you use gears with the lower spline pinion and just swap out the pinion yoke for the older style or is the pinion shaft/bearing/housing larger?

Not sure to be honest. I would assume the spline count was increased without increasing the diameter so as to not have to alter the housing. I could be wrong though.