Do ALL 6.7 SO engines get 3.42 gears?

[WXman]

Used to be, under the line item for the diesel engine, it also showed a change to 3.42 axle ratio. My truck does not show this. It never mentions any other ratio besides the 3.73 ratio that’s standard.

Anyway, I towed an enclosed trailer last weekend. Probably around 11k total weight. Truck never would downshift below 3rd gear ever…even when it CLEARLY needed to on the slower roads. Then on the highway it stayed in 6th most of the time, even in tow/haul mode. It would downshift to 5th on the steep hills. Tow/haul or not didn't seem to matter. The programming on this thing sucks. The 6.7L Powerstroke with 6R140 I came from was pretty much perfect. It would downshift as far as it needed to and keep RPMs up on slower roads, but on the highway it would stay in 6th always regardless of grade, no shifting around.

Guess next time I tow with this truck I’ll need to play around with the steering wheel buttons and lock 6th out on the highway and manually force it down to 2nd on slow hills.

Anyway, so I actually have 3.42 gears despite no mention of it?

 

[Units]

You have 3.73 which was standard on 19-24 trucks. 25+ have 3.42.

 

[Brutal_HO]

Used to be, under the line item for the diesel engine, it also showed a change to 3.42 axle ratio. My truck does not show this. It never mentions any other ratio besides the 3.73 ratio that’s standard.

Anyway, I towed an enclosed trailer last weekend. Probably around 11k total weight. Truck never would downshift below 3rd gear ever…even when it CLEARLY needed to on the slower roads. Then on the highway it stayed in 6th most of the time, even in tow/haul mode. It would downshift to 5th on the steep hills. Tow/haul or not didn't seem to matter. The programming on this thing sucks. The 6.7L Powerstroke with 6R140 I came from was pretty much perfect. It would downshift as far as it needed to and keep RPMs up on slower roads, but on the highway it would stay in 6th always regardless of grade, no shifting around.

Guess next time I tow with this truck I’ll need to play around with the steering wheel buttons and lock 6th out on the highway and manually force it down to 2nd on slow hills.

Anyway, so I actually have 3.42 gears despite no mention of it?

Cummins Engine choice matters not for rear end gears unless it's a dually max tow.

All 19-24 trucks standard rear end is 3.73.

4.10's available as an option on Hemi and standard on dually max tow.

Did you install larger tires and not reprogram the speedo?

 

[wrvond]

Other than more noise and vibration, mine operates pretty much identically to my erstwhile 2017 F350 DRW. Tow/haul is a function I didn't use then and I don't use now.

 

[Brutal_HO]

TH hits harder on the exhaust brake - at least it does for the AISIN.

 

[WXman]

Cummins Engine choice matters not for rear end gears unless it's a dually max tow.

All 19-24 trucks standard rear end is 3.73.

4.10's available as an option on Hemi and standard on dually max tow.

Did you install larger tires and not reprogram the speedo?

AWESOME!! I threw the numbers into a quick spreadsheet (trans ratios x axle ratio) and compared to my '19 F-250 6.7, it looks like this '24 2500 has a final drive gearing advantage in 3rd, 5th, 6th, and Reverse. The Ford is "deeper" in 1st and 2nd, and just barely in 4th. So, clearly that 80 HP/95 lb.ft. advantage on paper translates to the real world as well because it pulled so much harder in overdrive despite the gearing disadvantage.

My Ram does not have larger tires. She's 100% bone stock down to the air filter. I still really love her. Sounds like a tractor, drives like a tractor. I love it.