3:55 or 4:10

[buc1980]

I wander what better to have on the truck rear axle 3:55 or 4:10 to pull a 15000 lb FW.What the mile difference driving solo?

[Grit_dog]

NJRVer 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

Wow, 25,000 pounds of LEAD?

Tougher than carrying 25,000 pounds of say, bird seed? 🙂

Lol! Post of the day!

[NJRVer]

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

Wow, 25,000 pounds of LEAD?

Tougher than carrying 25,000 pounds of say, bird seed? 🙂

[transamz9]

Bedlam wrote:
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.

My truck with 3.42's won't shift into 6th gear until 65 with the TH on. With 385 hp/ 900 lbft running in fifth is basicly like a truck with 4.10's running in sixth. 55 is the shift point from 4th to 5th.

[Bedlam]

I get it - That's why I did not choose the 4.88 gearing option. If I drove faster, I would have chosen the 4.10's over my 4.30 ratio. Since My truck is not driven empty, my setup works well for my conditions.

[Turtle_n_Peeps]

4x4ord wrote:
Towing even a very heavy holiday trailer down the highway at 65 mph only requires about 120 horsepower. What is the purpose of having your engine revving 2000 rpm in 6th gear where it is capable of delivering close to 300 hp to the rear wheels, Having a 3.73 gear ratio iinstead of a 4.30 would bring that rpm down to about 1735 which is still plenty high.....At 1735 the new Powerstroke is capable of delivering about 240 hp to the rear wheels. When I need more power than that I am happy to see the truck drop a gear or two where it can more directly and efficiently transfer the higher power to the rear wheels.

Someone gets it. Refreshing. 🙂

[4x4ord]

Towing even a very heavy holiday trailer down the highway at 65 mph only requires about 120 horsepower. What is the purpose of having your engine revving 2000 rpm in 6th gear where it is capable of delivering close to 300 hp to the rear wheels, Having a 3.73 gear ratio iinstead of a 4.30 would bring that rpm down to about 1735 which is still plenty high.....At 1735 the new Powerstroke is capable of delivering about 240 hp to the rear wheels. When I need more power than that I am happy to see the truck drop a gear or two where it can more directly and efficiently transfer the higher power to the rear wheels.

[SoCalDesertRid1]

ROBERTSUNRUS 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

🙂 Hi, and how is this going to work with a 4 X 4? Not!

You only operate the rear axle in high when in 2wd. Lockout switch keeps from accidentally engaging 4wd when the rear is in high.

[Greentreena]

I've towed with 3.55 gears and converted the truck to 4.10 and liked it much better. That was an older truck with only a 4 speed auto.

With a modern 6 speed (or higher) transmission- I'm not sure I'd worry too much as there will always be the right gear. My current truck has 3.73s and they are great.

[ROBERTSUNRUS]

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

🙂 Hi, and how is this going to work with a 4 X 4? Not!

[SoCalDesertRid1]

The Gear Vendors is an overdrive unit, with a direct 1:1 low gear and a 20 percent overdrive high gear (0.8:1). To use it as an underdrive, one would need to pick a very low (numerically high) axle ratio, like 4.30, and then run the Gear Vendors in High when empty, for an effective axle ratio of 3.44.

[Bedlam]

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.

[lawnspecialties]

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.

[BenK]

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.

[rjstractor]

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.