- Oct 9, 2009
- Reaction score
- Midwest City, Oklahoma
- Vehicle Year
- Make / Model
- Engine Size
With 4.;10 gears, it locks up at 40. Used to lock up at 45 with 3.73's. The difference between 3.73 and 4.10 is 10%. So yup,. I can feel mine lock up at 40 mph.If you don’t have a gear hunting issue with the over drive on, leaving it on won’t hurt anything. Neither will leaving it off, though you might notice more fuel consumption.
At 40 mph, I doubt the torque converter is locking up.
And yes, on both my Ranger and my Lightning (SVT-F150), I turn the OD off as soon as the engine is running. Both are fitted with 4.10 gears and shift kits in their transmissions. With OD off, both are peppy as F---, and fun to drive. I typically leave OD off unless I'm on a road that has very few STOP signs or lights. In other words, the freeway.
Both my Ranger and Lightning shift into OD very near 40 mph. If it's turned on, which is very rare. But that is again, the difference between 3.73 and 4.10 gears.