Thor Forums

[Chance]

Originally Posted by Beau388

Not quite. The Ford 6-sp trans introduced in 2011 was designed from the beginning to be used only behind the 6.7 L diesel (800 ftlbs of torque @ 1,600 rpm) No way that 420 ftlbs of torque @ 3,000 rpm would ever hurt the trans in any gear.

I agree 100% and wouldn’t personally worry about the 6R140 which like you say was designed for the diesel’s much higher torque.

Two things that are interesting is that the 6R140 doesn’t actually have a direct gear ratio, so engine torque is always going through some gear ratio/multiplication. Most transmissions have a 1:1 ratio, but this one doesn’t. As far as stress on gears themselves and transmission in general, the worse case is usually 1st gear. I believe Ford may limit engine torque in 1st gear on some applications to prevent damage.

The new 10R140, if similar to 10R80 in design as stated by Ford engineers, has a 1:1 ratio in 7th and overdrive ratios in 8, 9, and 10th. Those who don’t like transmission shifting should probably avoid the new 10-speed. More gears means more shifts. That’s why Ford spent money putting them there.