Super duty 10 speed gear ratios
Very similar to the 1/2 ton ratios. They are probably all excellent but my personal preference is that they would have left reverse as a higher speed. I think it was 1:-3.4 in the 6 speed Super Dut...
Forum Discussion
4x4ord wrote:valhalla360 wrote:
For the fun of it, I pulled up a gear ratio to speed calculator:
With the ford 2.7turbo, 3.73 rear end, 4.86 reverse gear and 32" diameter tires...30mph is 5710rpm. Redline is listed as 5800rpm...Assuming you aren't running around all day in reverse, this shouldn't harm the engine.
If you drop back to 25mph, it's a much more sedate 4750rpm.
So even with the really deep granny reverse gear, you can tow (push?) at 30mph on occasion (at least theoretically).
I'm still trying to figure out what scenario this makes any sense.
- If you have any significant room that the slightest mistake doesn't put you into the ditch/wall, it's easier to turn the rig around.
- If its a tight narrow twisty road where you can't turn around, you just increase the difficulty level 10 fold getting up to 30mph (regardless of gear ratio)
Update: Looks like if you have the diesel, you are limited to around 20mph in reverse as the engine is governed at 3700rpm.
I'm not 100% sure what the gear ratio was for reverse in 2017. 2020 6r140s have a -3.4:1 and I've seen values of both -3.12:1 and -3.28:1 for the 6r140 as well. I have the 3.55 axle ratio and I believe 34" rubber mounted on my 20" rims.
search gear ratio calculator...you can plug in your exact info.
