F350: 4.30 or 3.73 Gears

Bedlam wrote:
It may depend on what type of camping you do whether 1st gear is low enough. If you primitive camp, you may find the transmission laboring as you are trying back in or pull out of a steep view site. If your camping consists of paved resorts, you won't have to worry about gear ratios or break over angles.

All the modern trucks have the dual range 4X with first gear in the ultra-low range having unbelievable power/torque or whatever. I was just using mine in an ice storm recently and I could roll down a steep, ice covered hill at about 2MPH. Pulling in/out of a tricky camp spot this gear would be plenty with any gear ratio.

Bedlam wrote:
It may depend on what type of camping you do whether 1st gear is low enough. If you primitive camp, you may find the transmission laboring as you are trying back in or pull out of a steep view site. If your camping consists of paved resorts, you won't have to worry about gear ratios or break over angles.

If I am towing into a primitive camp then I will have a 4 wheel drive.

In low range that is the same as having a 7:46 rear end. That will give me more torque that the tires can hold even if I have a large 5th wheel in tow.

It may depend on what type of camping you do whether 1st gear is low enough. If you primitive camp, you may find the transmission laboring as you are trying back in or pull out of a steep view site. If your camping consists of paved resorts, you won't have to worry about gear ratios or break over angles.

Grit dog wrote:

spoon059 wrote:

SolidAxleDurango wrote:
He will be cruising at higher RPMs with the 4.30.

I'm extrapolating a little bit, and didn't clarify. With the 4.30 gears and being able to stay in 6th gear, he will have lower RPM's than with 3.73 and being in 4th or 5th gear.

First, too many people, whether gas, diesel, Bow tie, blue oval etc worried about or trying to tow heavy in 6th gear, double OD. the 2nd OD in all these newer transmissions is a cruising gear for light weight highway travel.

That said, get the 4:30s with the gasser. It'll hold 3rd longer going up hill with a decent load hooked up. Both my 3.73 6.2 Fords will hit 2nd gear screaming on grades, every time. 5krpms plus every time to maintain normal hwy speeds of like 55-60mph.

And the 6.2 gas mileage is nothing to write Ford a thank you note over anyway, so if the truck is more hauler than daily driver get the 4.3 gears. Ain't going to make much difference on mileage.

If it is true that 6th and 5th years are not for towing it would seam to me the 3:73 would be the better choice as you will be using 5th and 6th gear less than if you had the 4:30 gear.

And if it takes 5000 rpm to pull your load at the speed you want it will always take 5000 rpm to pull that load at that speed regardless of the rear end ratio. It just will require a different transmission gear.

I've driven a Ford V10 with 3.73 gears and 4.30 gears and all the way through the gears the 4.30 wins hands down, I have friends with 6.7 Fords with 3.54 and 3.73 gears again the lower gears win. One of my Ford trucks with a 460 I changed from 3.73 to 4.10 night and day difference pulling the same load.

The 6 speed makes a dig difference because the second OD keeps the rpm down when cruising down the road in 6th pulling because the final gear ratio puts more available power to the ground.

No what is said the final mechanical advantage (rear gears) makes the difference, just go to any truck specs and see what happens to the towing capacity increases with lower gears.

Denny

Bedlam wrote:
Your axle ratio helps with the initial pull from a stop. Yes, you can run in 5th instead of 6th to have the same top end ratio, but what do you do on a steep incline where you stopped and now need to get moving? For some people the answer is shift in low range if you a 4wd, for others...

Any pickup truck made has more than enough power to pull fully loaded from a stop. Especially with an automatic transmission. (with a manual it's a different story)

In the old days with low power engines and 2 or 3 speed transmissions rear gearing was VERY important. Now days with the power modern engines put out and with 6 and above speed automatic transmissions rear gearing is "almost" a non issue.

IOW's, if one does the math, a 6 speed with long rear end gears has way more torque choices than the old 4 speeds with short gears of just a few years ago. It just does it in a different gear.

Look at towing contests of years past where the 3.73 rear gear Duramax out towed all comers on the Ike pass. Some even with 4.10 or lower gearing. The Dmax clearly put more HP to the ground where it counts.

Bedlam wrote:
Your axle ratio helps with the initial pull from a stop. Yes, you can run in 5th instead of 6th to have the same top end ratio, but what do you do on a steep incline where you stopped and now need to get moving? For some people the answer is shift in low range if you have a 4wd, for others...

BTW: Doesn't a higher rear end ratio put your transmission gear changes closer together?

Yes, higher numerically, lower gearing will help the gear splits a bit.

spoon059 wrote:

SolidAxleDurango wrote:
He will be cruising at higher RPMs with the 4.30.

I'm extrapolating a little bit, and didn't clarify. With the 4.30 gears and being able to stay in 6th gear, he will have lower RPM's than with 3.73 and being in 4th or 5th gear.

First, too many people, whether gas, diesel, Bow tie, blue oval etc worried about or trying to tow heavy in 6th gear, double OD. the 2nd OD in all these newer transmissions is a cruising gear for light weight highway travel.

That said, get the 4:30s with the gasser. It'll hold 3rd longer going up hill with a decent load hooked up. Both my 3.73 6.2 Fords will hit 2nd gear screaming on grades, every time. 5krpms plus every time to maintain normal hwy speeds of like 55-60mph.

And the 6.2 gas mileage is nothing to write Ford a thank you note over anyway, so if the truck is more hauler than daily driver get the 4.3 gears. Ain't going to make much difference on mileage.

Your axle ratio helps with the initial pull from a stop. Yes, you can run in 5th instead of 6th to have the same top end ratio, but what do you do on a steep incline where you stopped and now need to get moving? For some people the answer is shift in low range if you have a 4wd, for others...

BTW: Doesn't a higher rear end ratio put your transmission gear changes closer together?

Again gearing does not make power.

If you have two trucks pulling identical trailers and load the two trucks so your total weight is the same and are going up the same 6 % grade at 65 mph the torque and horsepower at the rear wheels will be the same regardless of the engine in the truck or the rear end gearing.