4.10 rear in new Ford F350

[dennych1]

A lot of leftovers have the 4.10 rear any one know if there would be a big difference in MPG towing or would it be negligible..?

[dodge_guy]

wnjj wrote:

FishOnOne wrote:

wnjj wrote:
Low geared rear axles are great, until you are rev’ed out and can’t pull the next gear.

WTF.... Back away from the booze and the keyboard.

Ever been tach’d out in 2nd pulling a steep hill but can’t hit 3rd? The lower geared truck will be moving slower than its higher geared counterpart. That was my point.

My 8.1L 4.10 revs hard at 60 when loaded down on a couple of I-5 hills in southern Oregon. It would rev a bit higher if I wanted to go a little faster but wouldn’t stay in the next gear. It has enough power to go 65-70 but the wrong gearing. For the record, I chose the 4.10 and would again. Just saying that nothing is perfect for all situations.

However with more transmission gear choices, towing gets easier. 😉

Seriously! Back away from the keyboard

[Grit_dog]

spud1957 wrote:

Grit dog wrote:
^ And this example is for the Diesel. OP hasn’t even said what engine he’s looking for, I think.
Surmising gasser since Ford doesn’t currently offer a 3.73 in the diesel though.
Does that change things?

He is looking at a diesel. No 4:10 gears in a gasser since 2010.

You’re correct. Solved the mystery!
Now what wuz the question again? Lol

[wnjj]

FishOnOne wrote:

wnjj wrote:
Low geared rear axles are great, until you are rev’ed out and can’t pull the next gear.

WTF.... Back away from the booze and the keyboard.

Ever been tach’d out in 2nd pulling a steep hill but can’t hit 3rd? The lower geared truck will be moving slower than its higher geared counterpart. That was my point.

My 8.1L 4.10 revs hard at 60 when loaded down on a couple of I-5 hills in southern Oregon. It would rev a bit higher if I wanted to go a little faster but wouldn’t stay in the next gear. It has enough power to go 65-70 but the wrong gearing. For the record, I chose the 4.10 and would again. Just saying that nothing is perfect for all situations.

However with more transmission gear choices, towing gets easier. 😉

[FishOnOne]

wnjj wrote:
Low geared rear axles are great, until you are rev’ed out and can’t pull the next gear.

WTF.... Back away from the booze and the keyboard.

[spud1957]

Grit dog wrote:
^ And this example is for the Diesel. OP hasn’t even said what engine he’s looking for, I think.
Surmising gasser since Ford doesn’t currently offer a 3.73 in the diesel though.
Does that change things?

He is looking at a diesel. 2010 was the last year 4:10s in a gasser.

[dodge_guy]

wnjj wrote:

Grit dog wrote:
^So this is just for the sake of argument, that if you cherry pick the exact weight, speed, torque curve, grade and scenery out the passenger window, you can find a spot where taller gears are slightly more efficient than lower gears?
What happens the rest of the time when the scenery changes?

The only variable involved is speed. For each speed you pick, one rear axle ratio or the other will have an advantage given the same transmission ratios. Pick the one that has the advantage at the speed you travel most often.

Low geared rear axles are great, until you are rev’ed out and can’t pull the next gear.

And that's not going to happen until you are well over 100mph. There is no way you can be rev'ed out at highway speeds, unless your under powered, in that case all the gear in the world isn't going to help you!

[wnjj]

Grit dog wrote:
^So this is just for the sake of argument, that if you cherry pick the exact weight, speed, torque curve, grade and scenery out the passenger window, you can find a spot where taller gears are slightly more efficient than lower gears?
What happens the rest of the time when the scenery changes?

The only variable involved is speed. For each speed you pick, one rear axle ratio or the other will have an advantage given the same transmission ratios. Pick the one that has the advantage at the speed you travel most often.

Low geared rear axles are great, until you are rev’ed out and can’t pull the next gear.

[Grit_dog]

^ And this example is for the Diesel. OP hasn’t even said what engine he’s looking for, I think.
Surmising gasser since Ford doesn’t currently offer a 3.73 in the diesel though.
Does that change things?

[Grit_dog]

^So this is just for the sake of argument, that if you cherry pick the exact weight, speed, torque curve, grade and scenery out the passenger window, you can find a spot where taller gears are slightly more efficient than lower gears?
What happens the rest of the time when the scenery changes?

[4x4ord]

4x4ord wrote:

Lynnmor wrote:

Me Again wrote:

Lynnmor wrote:

Me Again wrote:
. What you think you gain with the lower diff gears in negated by the steeper OD ratio. Think final gear ratio!

Keep in mind that the transmission is worked harder with higher diff gears.

You multiply the top gear ratio times the diff gear ratio, and the result is always more torque with the lower rear gears. Add to that, each gear change is less of a difference in road speed, keeping the engine at a better RPM.

That basically applies in first gear to get a load moving.

Out on highway one is in 5th and the other in 6th at the same speed. You are dismissing a taller 6th gear od ratio.

I am not dismissing anything, the multiplier (rear gear ratio) is the same in every gear.

So the 4.10 will put 15% more torque to the axle in every gear but it does not put more torque to the rear axle at every speed. So for instance at 60 mph on a 6% grade with 16k lbs in tow and foot to the floor the 6r140 will be in 4th with 3.55 gears and in 5th with 4.10 gears. The 3.55 will be putting 5% more torque to the rear axle. If that trailer is increased to a 22,000 lb 5ver the trucks will be slowed to 50 mph on a 6% grade. Both trucks will be in 4th gear. The 4.10 equipped truck will be running at 2518 rpm and the 3.55 equipped truck at 2180. The 4.10 will be putting 13% more torque to the rear axle. The 3.55 equipped truck will continue to slow down until it can drop to 3rd gear (48 mph). Bottom line is that 4.10s are advantageous for heavier trailers but for a 16k fiver you're better off with 3.55s.

[4x4ord]

Lynnmor wrote:

Me Again wrote:

Lynnmor wrote:

Me Again wrote:
. What you think you gain with the lower diff gears in negated by the steeper OD ratio. Think final gear ratio!

Keep in mind that the transmission is worked harder with higher diff gears.

You multiply the top gear ratio times the diff gear ratio, and the result is always more torque with the lower rear gears. Add to that, each gear change is less of a difference in road speed, keeping the engine at a better RPM.

That basically applies in first gear to get a load moving.

Out on highway one is in 5th and the other in 6th at the same speed. You are dismissing a taller 6th gear od ratio.

I am not dismissing anything, the multiplier (rear gear ratio) is the same in every gear.

So the 4.10 will put 15% more torque to the axle in every gear but it does not put more torque to the rear axle at every speed. So for instance at 60 mph on a 6% grade with 16k lbs in tow and foot to the floor the 6r140 will be in 4th with 3.55 gears and in 5th with 4.10 gears. The 3.55 will be putting 5% more torque to the rear axle. If that trailer is increased to a 22,000 lb 5ver the trucks will be slowed to 50 mph on a 6% grade. Both trucks will be in 4th gear. The 4.10 equipped truck will be running at 2518 rpm and the 3.55 equipped truck at 2180. The 4.10 will be putting 13% more torque to the rear axle. Bottom line is that 4.10s are advantageous for heavier trailers but for a 16k fiver you're better off with 3.55s.

[Lynnmor]

Me Again wrote:

Lynnmor wrote:

Me Again wrote:
. What you think you gain with the lower diff gears in negated by the steeper OD ratio. Think final gear ratio!

Keep in mind that the transmission is worked harder with higher diff gears.

You multiply the top gear ratio times the diff gear ratio, and the result is always more torque with the lower rear gears. Add to that, each gear change is less of a difference in road speed, keeping the engine at a better RPM.

That basically applies in first gear to get a load moving.

Out on highway one is in 5th and the other in 6th at the same speed. You are dismissing a taller 6th gear od ratio.

I am not dismissing anything, the multiplier (rear gear ratio) is the same in every gear.

[Grit_dog]

The new(er) 8 and 10 speed transmissions typically have a lower first gear ratio and the same or a bit higher final overdrive ratio, with more splits in between. Therefore shorter final drive gearing = even more snort down low and through the gears and the same or a bit less rpms in top gear as years past.
Plus we’re not talking diesels here. The thread was about gassers, which benefit even more from this because they have large rpm ranges and “need” more gear reduction to pull bigger loads effectively.
Would anyone complain about having, say, 30 more hp? That’s like complaining about having 4.10s in lieu of 3.73s.

[philh]

and the new 10 speed trans?