2011 5.0 L F-150: from 3.31 to 3.73
10-21-2011, 03:57 PM
#21
Senior Member
Only Ford Engineers know for sure.
Could be to reduce transmission temps further from reduced converter slip, leading to longer transmission life. Could be just because people will buy them. What's your theory?
Could be to reduce transmission temps further from reduced converter slip, leading to longer transmission life. Could be just because people will buy them. What's your theory?
Last edited by engineermike; 10-21-2011 at 04:01 PM.
10-21-2011, 04:02 PM
#22
I don't know about everyone saying it'll be such a big difference. I raced my lariat EB agaisnt my buddies XTR EB (Canada) twice. Mine is heavier as I have roll-n-lock cover and wooden box liner and all my pushing gear in the back seat. He was basically empty aside from maybe some leaves in the box. I'm 280lbs and he's 170lbs. So no matter how you figure it I've got to be heavier, at 120kph both times I was a full truck length ahead of him both times. Rolling start, same thing. He has 3.73 e locker and I've got 3.31 open. Maybe it's the low end grunt of the eb but gearing didn't seem to effect our test.
10-21-2011, 04:55 PM
#23
BAMF Club
Low gears = towing and acceleration
High Gears = Fuel Mileage.
10-21-2011, 05:44 PM
#25
Senior Member
When weighing this option, keep in mind that the 6R80 transmission in the new F150's using a 3.31 gear is the same 1st gear total ratio as the older 4R75 running a 4.86 gear. Once you get out of 1st gear, there is no advantage to shorter rear gears.
IMO, that's a lot of cost and effort to go from what would've been a 4.86 (which most people would find more-than-adequate) to what would've been a 5.47 with the old tranny.
IMO, that's a lot of cost and effort to go from what would've been a 4.86 (which most people would find more-than-adequate) to what would've been a 5.47 with the old tranny.
10-21-2011, 06:24 PM
#27
Senior Member
Once you get out of 1st gear, there is no advantage to shorter rear gears.
10-21-2011, 06:32 PM
#28
Senior Member
I understand gearing perfectly fine....it's your statement as a whole that I do not understand.
Axle gearing has an impact on your acceleration in every gear...not just first gear. I also think most people will agree that trucks of yester-year were slugs to tow with, which leads me to this statement: A 13.8 final drive for first gear is not sufficient, which is why 3.73's and 4.10's are offered.
Axle gearing has an impact on your acceleration in every gear...not just first gear. I also think most people will agree that trucks of yester-year were slugs to tow with, which leads me to this statement: A 13.8 final drive for first gear is not sufficient, which is why 3.73's and 4.10's are offered.
If you think that a 13.8 final drive for 1st gear isn't sufficient, then you must also think that a 4.86 rear gear in a 2008 wouldn't be sufficient. If you think that, then fine, just realize that it's the same thing.
Last edited by engineermike; 10-21-2011 at 06:41 PM.
10-21-2011, 06:41 PM
#30
Senior Member
Thread Starter
Just to be clear about tranny gear ratios. This is taken from the salesman's printout I got when ordering the truck.
5.0 L V8
360 HP at 5,500 RPM
380 lb-ft torque at 4,250 RPM
GEAR RATIOS:
1: 4.17
2: 2.34
3: 1.52
4: 1.14
5: 0.86
6: 0.69
Reverse: 3.40
The new 3.73 diffs will effect final drive ratio and torque in all gears! I remember when I changed ratios on my big truck from 3.73 to 3.42 the driver satisfaction went out the window when picking up speed. I got it partially back after I changed the 3.42 to 3.58 (the one I have now). By the way, my 13 speed tranny in the heavy truck has the top gear ratio of ... 0.73, not 0.69 Ford puts in F-150s.
5.0 L V8
360 HP at 5,500 RPM
380 lb-ft torque at 4,250 RPM
GEAR RATIOS:
1: 4.17
2: 2.34
3: 1.52
4: 1.14
5: 0.86
6: 0.69
Reverse: 3.40
The new 3.73 diffs will effect final drive ratio and torque in all gears! I remember when I changed ratios on my big truck from 3.73 to 3.42 the driver satisfaction went out the window when picking up speed. I got it partially back after I changed the 3.42 to 3.58 (the one I have now). By the way, my 13 speed tranny in the heavy truck has the top gear ratio of ... 0.73, not 0.69 Ford puts in F-150s.