F350: 4.30 or 3.73 Gears

Denny & Jami wrote:
The rear end gears are the final torque multiplier, so the 4.30 gears will give you more power at the pavement.

Here's a simple explanation, if you have a 10 to 1 torque multiplier on a wench it will take 100 ft lbs of torque to apply 1000 lbs of torque to the bolt but if you use a 5 to 1 it will take 200 lbs of torque to get the same 1000 lbs at the bolt.

So even when using the lower transmision gear you will not get the same torque to the rear wheels when using 3.73 gears over the 4.30 gears.

Yes and no. You're leaving out the fact that the transmission multiplies torque exactly the same way as the rear axle. It makes no difference where the torque is multiplied. If third gear is 1:1 and fourth is .67:1, a 3.73:1 rear axle in third gear has a torque multiplication of 3.73:1. A 4:30 rear axle in fourth gear has a torque multiplication of only 2.88:1.

CWSWine wrote:
Being a Ford person I wouldn't buy 2016 if I could wait. The 2017 looks like it's going to be big improvement over the 2016.

No doubt the 17's will be better. But I need a new truck for a X-country trip this August and doubtful the new model will be available that early. Also always a little concerned about first year vehicle introductions as there always seems to be issues that need to be resolved.

I had the 4.30 and it towed great. Replaced with a 4.10 in the RAM. I always buy the largest gears available since the primary duty of the truck is to tow (though it is also a daily driver).

With the 4.30 I always wondered how much I could have saved on fuel had I gone with the 3.73. Now had I gone with the 3.73 I'd have been wondering how much better the towing etc experience would be if I'd have gone with the 4.30. In the end it's worth more to me to have the "best" tow experience I can, others may feel different.

Denny & Jami wrote:

RCMAN46 wrote:

Chuck_thehammer wrote:
I would like the 4:30...


2 wheel drive 3:73.. very towable..

the 4:30 would allow a higher gear going up hill.. less rpms
engine is fine at 4,000 rpm's.. but body, sound, vibrations..

my opinion

The 4:30 will not allow less rpms going up a hill.

If climbing a hill requires x horsepower then the the engine will have to turn y rpm to make that horsepower.
Thus same rpm regardless of the rear end ratio provided you have a transmission that will allow the required rpm. The newer 6 and 8 speed transmissions do this very well.

There is nothing wrong with using 6 th gear with a 4:30 and 5th gear with the 3:73. The final gear ratio to the rear wheels will be very close.

Rear end Gearing does not make more power.

The rear end gears are the final torque multiplier, so the 4.30 gears will give you more power at the pavement.

Here's a simple explanation, if you have a 10 to 1 torque multiplier on a wench it will take 100 ft lbs of torque to apply 1000 lbs of torque to the bolt but if you use a 5 to 1 it will take 200 lbs of torque to get the same 1000 lbs at the bolt.

So even when using the lower transmision gear you will not get the same torque to the rear wheels when using 3.73 gears over the 4.30 gears.

Denny

Torque is not power. And no; it's not semantics. Power is a timed formula over time. Torque is just the amount of twist put to a shaft.

Think of this analogy:
I can put out a lot of torque on a bike. Over 200 ft/lbs to be exact. If I had a 4 foot crank (think of the crank as a gear) on my bike I could put out more torque to the wheel than a new 6.7 Cummins could produce. :E

Could I put a hitch on the back of my bike and out tow a Modern Ram? Of course I couldn't; that's silly, and the reason I can't is because I can only put out about 1/4 to a 1/2 a horse"power".

If you still believe that torque makes power just do this. Take your truck to a dyno days and chassis dyno your truck. Make two pulls. One in first gear and one in the gear closest to direct drive (1 to 1) as you can get. This will show you the exact amount of power that gets to the ground. If you're correct the first gear pull should put out more horse(power) to the wheels than my direct gear pull. Go give it a shot and see what happens.

CWSWine wrote:
Being a Ford person I wouldn't buy 2016 if I could wait. The 2017 looks like it's going to be big improvement over the 2016.

But one might be able to get a STEEP discount on a 2016 as the 2017's start coming out... While the 2017's are a marked improvement, the 2016's are still a darn fine truck.

Being a Ford person I wouldn't buy 2016 if I could wait. The 2017 looks like it's going to be big improvement over the 2016.

RCMAN46 wrote:

Chuck_thehammer wrote:
I would like the 4:30...


2 wheel drive 3:73.. very towable..

the 4:30 would allow a higher gear going up hill.. less rpms
engine is fine at 4,000 rpm's.. but body, sound, vibrations..

my opinion

The 4:30 will not allow less rpms going up a hill.

If climbing a hill requires x horsepower then the the engine will have to turn y rpm to make that horsepower.
Thus same rpm regardless of the rear end ratio provided you have a transmission that will allow the required rpm. The newer 6 and 8 speed transmissions do this very well.

There is nothing wrong with using 6 th gear with a 4:30 and 5th gear with the 3:73. The final gear ratio to the rear wheels will be very close.

Rear end Gearing does not make more power.

The rear end gears are the final torque multiplier, so the 4.30 gears will give you more power at the pavement.

Here's a simple explanation, if you have a 10 to 1 torque multiplier on a wench it will take 100 ft lbs of torque to apply 1000 lbs of torque to the bolt but if you use a 5 to 1 it will take 200 lbs of torque to get the same 1000 lbs at the bolt.

So even when using the lower transmision gear you will not get the same torque to the rear wheels when using 3.73 gears over the 4.30 gears.

Denny

That is why it has a gear box, do semi trailers hall op hill in top gear?
Frank.

lawnspecialties wrote:
Agreed. My F350 SRW with the 6.2 and 3.73 used to pull the Work & Play in my signature. Around town isn't too bad. You're not going fast. Once you hit highway speeds, it was not a happy camper. Nothing like doing around 60 mph and when you hit a decent incline, it would drop down to third gear screaming.

That's why I bought the diesel.

That's barely 4000 rpm at 60 mph. The 6.2 not even working hard at that point. 4000 rpm with a engine that red lines at 6000 rpm is not screaming.

I drive a F550 with a power stroke that's screaming at 75 mph, it's truning 3200 rpm it red lines at 4000 rpm.

To the op if your going to tow it alot with it go with the 4.30 if not the 3.73 will work fine. Both are a good gear with in that truck.

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.

Correct that there will be more leverage with lower (higher numerically) gears in the rear end... Which may allow the driver to hold a higher transmission gear longer.

But that varies with each and every driving situation how one gear ratio might behave compared to another gear ratio.

Strictly speaking.... For a specific road speed, given gear-for-gear comparison, the lower geared truck will always spin more RPM.