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Super duty rear ratio!

muddyriver
Explorer
Explorer
I'm starting to research buying a new truck. I'm defiantly going diesel this time and wondering what rear end a person should get. I'll be towing a camper around 9K. with about 1200K in the box of the truck. I'm hoping to buy used. My 6.2 had 3:73 which pulled our 8600# camper well, but wish it would have had the 4:10 in it. Does a person go to 3:55 or stay at 3:73 or even move up to 4:10. I would appreciate peoples information. Kind Regards, Nathan
20 REPLIES 20

BB_TX
Nomad
Nomad
I have a 2012 F350 6.7 with the 3:55. Tows the 12,000 lb 5er fine over CO mountain passes. Cruises at 70 in 6th on flat to rolling highways.

Farm_Camp
Explorer
Explorer
I just got a 2017 (in my signature) and it's got the 3:31 rear end, and it's not locking, or even limited slip... It's the truck that I could find and afford mind you. I'm not going to campaign for my set up. I do not have experience towing with the other ratios... AND... I've only towed about 300 miles with this setup so far...

With those 4 million disclaimers stated... I can not believe how much better this truck tows than my 2010 5.4L did. My trailer is at least 8300# (Dry/Fantasy weight)

Back to the truck... This engine paired with the 6spd tranny... It's an amazing difference in experience. I guess in short (and other opinions may vary widely) I would not shy away from the 3.31 if the rest of the truck was want you wanted ( you said looking used)... If I had the budget to order whatever I wanted, well.... Haha..

Anyway - just one Man's (limited) experience with the 3.31 - take it for whatever. 🙂 I loved my old "Blue Monster", but, I don't want it back! 🙂
TV: 2010 F250 XLT 4X4 SC SB 5.4L 3.73 - "The Blue Monster" (2013-2018) Traded at 100K
TV: 2017 F250 XLT 4X4 CC SB 6.7L PD 3.31 - "The Silver Streak"
TT: 2014 Starcraft Autumn Ridge 329BHU

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alexleblanc
Explorer
Explorer
Unless you’re looking at a drw f350 the diesel in the f250 and f350 srw options are 3.31 and 3.55, the 3.55 are automatic if you go for 20” wheels. Any version of the diesel super duty will pull that TT.
TV - 2017 F350 CCSB SRW Platinum 6.7 + 5er - 2021 Grand Design Reflection 311 BHS + B&W Companion
On Order - 2022 F350 CCSB SRW Platinum 6.7

Dukecity426
Explorer
Explorer
muddyriver wrote:
I'm starting to research buying a new truck. I'm defiantly going diesel this time and wondering what rear end a person should get. I'll be towing a camper around 9K. with about 1200K in the box of the truck. I'm hoping to buy used. My 6.2 had 3:73 which pulled our 8600# camper well, but wish it would have had the 4:10 in it. Does a person go to 3:55 or stay at 3:73 or even move up to 4:10. I would appreciate peoples information. Kind Regards, Nathan


We have the 3:73 and it does fine. With the power the newer diesels have, one could go with the 3:55. Being that you are buying used, you should research the specs (especially the torque) of the diesel engine. When we are towing and I am in "tow mode" usually the (transmission) will not shift into 5th gear until 60 MPH. I am used to it now, as we have owned this truck for 14 years. Hope this helps............Bruce
2004 GMC 4X4 D/A CC SB, "Juice/Attitude", 4" SS Exhaust, AFE intake, 2018 Reflection 29RS, two AC's, Reese 16K Slider, Bilstein shocks, 2 Honda EU 2000i generators.

Colo_Native
Explorer
Explorer
I have a F250 with 3:55 and tow about 10000# no issue and I pull in the Rockies a lot
2015 Winnebago Forza 34T
pushed by a 2011 Fusion Hybrid or 2020 Escape Hybrid
Retired DFD

Turtle_n_Peeps
Explorer
Explorer
For that weight a 3:55 would be fine.
~ Too many freaks & not enough circuses ~


"Life is not tried ~ it is merely survived ~ if you're standing
outside the fire"

"The best way to get a bad law repealed is to enforce it strictly."- Abraham Lincoln