Ford F-250 7.3 Gas Engine Axle Ratios

lenr wrote:
My opinion--yours will vary: Ford reference only.
Back in the days of the 4R100 transmission with its first gear ratio of 2.71 launch was a problem. When Ford came out with the 5R110 they split the old 1st into 2 ratios with the top 3 gears staying the same ratio. With a new 1st gear of 3.09 launch was improved. The 6R140 went to 3.97; more improvement. The 10R140 uses a 4.615 ratio. It is hard for me to believe that launch would be a problem with any axle ratio.

I have the 6R140 with 3.73, and agree, I have no issue with launch. The 10R should be a stump puller! I have posted before, that where the 6R140 comes up short is the 3.12 reverse. If reverse was 4.695, like the 10R140, it would be a non-issue. I often use 4-low to back my FW up an incline. At least they did correct this, that IMO, was the 6R140s only weakness.

Jerry

My opinion--yours will vary: Ford reference only.
Back in the days of the 4R100 transmission with its first gear ratio of 2.71 launch was a problem. When Ford came out with the 5R110 they split the old 1st into 2 ratios with the top 3 gears staying the same ratio. With a new 1st gear of 3.09 launch was improved. The 6R140 went to 3.97; more improvement. The 10R140 uses a 4.615 ratio. It is hard for me to believe that launch would be a problem with any axle ratio.

RoyJ wrote:

dodge guy wrote:

kellem wrote:

dodge guy wrote:

kellem wrote:
Bought my 7.3 gas strictly for towing our 30 ft trailer and the 3.55 gears doesn't acknowledge a trailer is in tow.

4.30, 3.73, 3.55....10spd makes them feel the same.
Tremor sitting on 35" tires, maybe 4.30 is justified. Imo

But how do you know different gears won't make a difference towing your trailer?

It would be marginal towing at only half the trucks capacity.

Exactly! But if towing more weight that’s when the deeper gears make a difference!

With 8 / 10 spd transmissions, the only places it makes a difference is starting out in 1st, and ability to use top gear.

Other than that, in gears 2 - 9, with such close ratio, there's enough overlap your towing experience is identical.

i.e. the 4.30 truck in 6th would be within a few hundred rpm of a 3.55 truck in 5th, and a given road speed.

If that’s the case then why do the manuf’s offer different ratios. I know for a fact that a few hundred RPM makes a difference when towing. 300 lower in one gear can really help.

dodge guy wrote:

kellem wrote:

dodge guy wrote:

kellem wrote:
Bought my 7.3 gas strictly for towing our 30 ft trailer and the 3.55 gears doesn't acknowledge a trailer is in tow.

4.30, 3.73, 3.55....10spd makes them feel the same.
Tremor sitting on 35" tires, maybe 4.30 is justified. Imo

But how do you know different gears won't make a difference towing your trailer?

It would be marginal towing at only half the trucks capacity.

Exactly! But if towing more weight that’s when the deeper gears make a difference!

With 8 / 10 spd transmissions, the only places it makes a difference is starting out in 1st, and ability to use top gear.

Other than that, in gears 2 - 9, with such close ratio, there's enough overlap your towing experience is identical.

i.e. the 4.30 truck in 6th would be within a few hundred rpm of a 3.55 truck in 5th, and a given road speed.

kellem wrote:
One more element I might add regarding the new 10 spd transmission is you can lockout gears on the fly which is ideal for towing.

Can't you do that with any of the HD trans?
But yes it is a nice feature.

One more element I might add regarding the new 10 spd transmission is you can lockout gears on the fly which is ideal for towing.

Get the 4.30's. Keeps the engine in it's sweet spot when towing / hauling. I chose the deeper gears with my gasser and am very happy with it. I get at or better mileage that my friends with the 3.73 axle as the engine doesn't have to work as hard to get things moving. Transmission holds gears and doesn't hunt or shift excessively at all. I am running the 6spd.

That’s what mine does as well. When towing, it uses all gears. We’re out with it now.

On my truck with the transmission in normal mode or economy mode it takes off in first gear skip second and goes to third and it skips fourth into fifth and then shifts the rest of the gears out

kellem wrote:

dodge guy wrote:

kellem wrote:
Bought my 7.3 gas strictly for towing our 30 ft trailer and the 3.55 gears doesn't acknowledge a trailer is in tow.

4.30, 3.73, 3.55....10spd makes them feel the same.
Tremor sitting on 35" tires, maybe 4.30 is justified. Imo

But how do you know different gears won't make a difference towing your trailer?

It would be marginal towing at only half the trucks capacity.

Exactly! But if towing more weight that’s when the deeper gears make a difference!