I am: Bob .
Join Date: Nov 2004
Vehicle: 2003 Ford Ranger
Drive Type: 4x4
Total Props: 19
The current 5RxxE 5-speed auto is just a newer version of the earlier 4RxxE 4-speed using relatively minor mechanical upgrades and more sophisticated software controls. 2nd gear in the new trans is a combination of 1st and overdrive which notches it in between the old first and second (now first and third).
At larger Throttle Position, like heavy acceleration or towing, the transmission uses the close ratio 2nd gear for improved performance. At lighter throttle it is unnecessary and it is skipped.
Why not just let it shift through all the gears, even at low TP? I don't have any definite info on that but I do know that the 1-2 and 2-3 gear shifts in the 5-speed are much more difficult to calibrate. Those gear changes require the coordinated shifting of both the 3-speed Simpson gearset and the overdrive gearset. So, shift harshness could be one reason to avoid those and use the smoother 1-3 shift for casual acceleration. A reduction in shift busyness could be another reason to skip it under light throttle..
Comparison of 4RxxE 4-speed and 5RxxE 5-speed (current Ranger):
4th 0.75 (1.00 x 0.75)
2nd 1.85 (2.47 x 0.75)
5th 0.75 (1.00 x 0.75)
1st = Simpson 1st
2nd = Simpson 1st w/OD
3rd = Simpson 2nd
4th = Simpson 3rd
5th = Simpson 3rd w/OD
2003 FX4 Level II, Supercharged 5.0L V8, Headers,Duals 4R70W auto, BW4406 manual T/C
Aussie Locker, Torsen L/S, 4.10's, Bilstein 7100 rezzies, Cadillac/Mustang rear discs, Duff traction bars
Keypad Entry, Lock LEDs, ABS switch, sway bar discos, Heated seats, Explorer EATC, Trip Computer and consoles
5.0L V8 swap: Click
2003 XLT 2.3L M5OD-R1 reg cab beater, 2011 Taurus SEL, 2016 C-MAX Energi Plug-in Hybrid