Thanks thats what I need to know
2020 F250 7.3 10 spd rear diff order question
- Thread starter yfarm
- Start date
billiebob
Well-known member
The most efficient gear for towing is direct. Not sure how many overdrive gears the 10 speed has but gear it to turn 3K rpm in direct on the highway. The top 2 or 3 gears can be used to drop rpms when cruising empty. And pick that 3Krpm at 60mph with the tires you really want. 35s? or 37s?
If Ford figures 3.55s work with 32s..... for 35s/37s..... definitely get the deeper gearing. Most Ford factory options are incredible bargains. Buy any you think you might eventually want.
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Explorerinil
Observer
I’ve had both sizes in the Toyo at 2, the 285/75r17 was about the same height just narrower.
Explorerinil
Observer
If I were ordering this truck, I would order it with 4:30 gears. Down the road you may want 37’s. Carli now builds a trailer hitch for super duties that allows for a 37 inch spare in the stock spare tire location.
check out tfl truck no pavement needed they did a review of it.
check out tfl truck no pavement needed they did a review of it.
Your kidding right, there is so much information out there on gear ratio and tire size. Buddy at work thought his diesel was just fine towing with factory gears and 35’s. Blew up that tranny no problem. So after trans rebuild and then gears wow everything back to or real close to factory specs. It’s not just the OD that’s the problem all gears throw the motor out of power range.
Changing tires and not re-gearing is like Putting one large tire on your truck and saying it’s fine the other three are the right size.
Changing tires and not re-gearing is like Putting one large tire on your truck and saying it’s fine the other three are the right size.
badm0t0rfinger
Raptor Apologist.
My 295/75R16 BFG KOs were just a bit bigger than I had expected, just a hair over 33 inches when mounted and on the Jeep. A 315 is closer to a 35x12.5R17 but still smaller (maybe half an inch), so I would have to believe a 285/75R17 would be close to a full 2 inches in size difference.
Grassland
Well-known member
Full 2 inches in size difference in regards to which tire?
If you mean the 35" I don't see how, if the 35 runs 34.5 OD in reality.
Your 295/75R16 being a 33x11.5r16 essentially (33.4x11.6R16), and a 285/75R17 is 33.75x11.25R17
badm0t0rfinger
Raptor Apologist.
@Grassland I may have accidentally did my math with the tire in question being a 285/75R16 instead of R17. R17 is probably gonna be 33.5, but even then my truck had 35s and they were only just a hair less than 35 when measured mounted. I wouldn't think those two would be at all close, now on the other hand a 315/75R17 would probably be close enough to use in a pinch, however I wouldn't do in regularly.
jadmt
ignore button user
one is a Toyo at2 in 285/75-17 and the other a Toyo at2 in 35x12.5-17
