2024 F350 SRW Rear Gear

[pacbj]

Looking to buy a new F350 SRW. I currently have a 18 F250/6.7/3:55 rear end, 6 speed auto. Tows the high country like a freight train. I’m seeing a lot of the new trucks with 3:31’s in them with the 10 speed tranny. Wondering if anyone has any experience with the higher gears and your thoughts. Thanks in advance

[Foldbak]

My 2020 GMC Duramax 10 speed Alison is amazing. The shifting is smooth through all the gears. The rear end is a 3.42:1. Engine 445 HP and 910# torque. The new trucks are beasts!

[Da40flyer]

We have a 2022 6.7 F350 LB SRW and we ordered it specifically with 3.31 gears. It has more than enough torque to get you up and going with the 10 speed. No need for more gearing in my opinion. Plus you get the benefit of lower rpm at freeway speeds.

[LeftOverParts]

We have the ‘21 F350 SRW 6.7 10 spd with the 3:55s. Also using stock tire size 275/70/18 with Nitto off-road tires. There is one place we tow on a windy, steep hill where it’s best to be in 2nd for about 5 miles. I think it would be fine on 3:31s. Happy with our set-up.

You might consider if you will upsize your tires, how often you tow, and what kinds of terrain you usually encounter.

[mlh]

It really doesn’t matter much. With the 10 speed you have 3 over drive gears. With the 323s you just won’t stay in the higher gears quite as much.
Lynwood

[MandK]

The 3.55 will get better mileage towing than the 3.31’s, and the 3.31’s will get better mileage running hwy speeds not towing. The difference isn’t much, like 1 mpg or less.
Either is fine for pulling, there’s plenty of engine and tranny to make up the difference.
If I were ordering a truck for full timing or towing a lot I’d go 3.55. Not towing a lot, 3.31.
Buying off the lot…doesn’t matter imo.
We bought ours in early ‘21 when ordering was taking a year and no dealer within 300 miles had 5th wheel/gooseneck packages so we went out to the mid west truck shopping. All the dealers that had trucks on the lot prepped for towing had the 3.55’s in them so that’s what we got.

[Diesel guy]

Get the 3.55s. The 10 Speed has a higher 10th gear OD .632 then the 6 speeds 6th gear .673. If you get the 3.31s it will shift more. These engines like to run around 2000 RPMs. The 3.55s is a better overall gearing.

[MandK]

I guess the picture says it best. This was towing yesterday. I got the 3.55’s with 20” wheels because that’s how the dealers ordered the trucks that have the tow packages where we bought our truck. I’d order the 3.55’s again if I was buying.
1500 rpm, doesn’t shift down much, very economical, considering.