3:55 or 4:10

I'm happy with 4.30's, but do not drive over 65 mph. Many people have to lock out top gear when towing with lower ratios - My truck is used exclusively for RV duty, so I am happy being able to make most of the drive in 6th gear and the worst hills in 4th.

I used to have a 2011 F450 with the 4.30. I always thought it was overkill but when I bought my '15 F350 with the 3.55, it was for a TT toy hauler. But now we have the Vengeance at well over 15,000 lbs. and I was seriously concerned about that gearing.

The 3.55 is perfect for us. We have no mountains but typical interstate travel is a breeze for the truck. Getting onto the highways is strong and setting the cruise at 70 mph is no problem and it rarely ever drops out of 6th gear.

Don't worry about the 3.55 at all.

add that is my thinking for now on my GMT400 7.4L Suburban with 4.1's

By installing a gear splitter function my 4 speed 4L80E will then
have 8 forward gears...AKA close ratio like the current gen of higher
number of gears.

Double OD too and noodling whether 0.5 or 0.75 on the Gear Vendors. OEM
4L80E is 0.75, IIRC, to provide a @ the drive shaft ratio of approx 0.56
in 2nd OD

Change both diff's to something like 4.54 ratio or even higher numerically
and the why of the decision whether 4.54's or 5.x's...but then the
pinion might be too small and have to change the OEM carrier for the reach...

Above applies to any vehicle and the available ratios will be specific to that
OEM and aftermarket offerings...

A cam to bring my OEM 7.4L's 410 ft/lbs at ~1,400 RPM up to +500 ft/lbs
but decision whether to bump the red line above the OEM set 4.8K RPMs
as I drive TVs to torque and my cars to HP...ever since the divorce,
no one demanding luxury & +30 footer stuff...toy hauler in the 28'
range will be fine for me and whomever

So that rat big block looking likely with a red line around 6K RPMs...

rjstractor wrote:

Chuck_thehammer wrote:
that over/under drives the transmission. been available for many years..

I am talking about a 2 speed rear end... like a 3:73 and a 4:30.

they are NOT the same thing.

But the net effect is the same. That's why OTR trucks have transmissions with 9 to 18 speeds and typically have single speed rear axles. Modern six speed transmissions have made split rear ends unnecessary, especially with the abundance of power available.

Chuck_thehammer wrote:
that over/under drives the transmission. been available for many years..

I am talking about a 2 speed rear end... like a 3:73 and a 4:30.

they are NOT the same thing.

But the net effect is the same. That's why OTR trucks have transmissions with 9 to 18 speeds and typically have single speed rear axles. Modern six speed transmissions have made split rear ends unnecessary, especially with the abundance of power available.

DRW don't come in 3.55. 3.73 or 4.30. If your gonna spend that kinda $$, fuel mileage shouldn't matter. 4.30 limited slip is what you will want.

Chuck_thehammer wrote:
I do wish Eaton made a 2 speed rear end for pickup trucks..

I used to drive a White with a 5 speed transmission and a 2 speed rear end.
carrying 25,000 pounds of LEAD...almost daily

I certainly agree with this.

Unfortunately, the smallest 2-speed rear axles available are over 20,000 lbs GAWR, so far as I'm aware. Too big for pickups.

A 2-speed direct/underdrive auxiliary transmission with 1:1 and 1.2:1 ratios would be nice too.

So the 2017 f350 drw now offers a 3.55 final drive ratio? If so I might even get a dually next time. If you run in 4th gear with 3.55 gears pulling hills you will be running similar rpm as 5th gear with 4.10 gears. 4th with 3.55 is a more efficient selection. Why would you want your transmission to run in overdrive - speeding things up just to slow it back down with the rear end gears. There is power lost in speeding things up and more power lost slowing it back down again. On the low end 935 ft lbs of torque running through 1st gear on the 6r140 certainly doesn't need 4.10 gears to get a little 15000 lb trailer rolling.

Chuck_thehammer wrote:

TexasRangerRzR wrote:

Chuck_thehammer wrote:
I do wish Eaton made a 2 speed rear end for pickup trucks..

I used to drive a White with a 5 speed transmission and a 2 speed rear end.
carrying 25,000 pounds of LEAD...almost daily

https://www.gearvendors.com/

that over/under drives the transmission. been available for many years..

I am talking about a 2 speed rear end... like a 3:73 and a 4:30.

they are NOT the same thing.

Yes, I know ... but it is available.

TexasRangerRzR wrote:

Chuck_thehammer wrote:
I do wish Eaton made a 2 speed rear end for pickup trucks..

I used to drive a White with a 5 speed transmission and a 2 speed rear end.
carrying 25,000 pounds of LEAD...almost daily

https://www.gearvendors.com/

that over/under drives the transmission. been available for many years..

I am talking about a 2 speed rear end... like a 3:73 and a 4:30.

they are NOT the same thing.

FishOnOne wrote:

buc1980 wrote:
I TALK ABOUT A 2017 FORD DRW DIESEL

Even more reason not to worry about gears.

^^^^^^ This.