Let’s talk Rear Axle - 4.7 vs 4.46

[Gamecock]

I was wondering event this too and am having a tough time deciding. If I am NEVER gonna off-road is there any benefit to the Sasquatch package At all?

Sure. Appearance is greatly improved; and possibly resale value improvement.

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[Uintafly]

How noticeable do you all think the performance change from the 4.46 to the 4.70 if someone jumps from 33" to 35" tires. Between the M/T's being impractical for someone driving up Little Cottonwood Canyon 60 times a ski season, and the fact that this will start as my wife daily driver (she didn't want 35" tires), we went with the non-squatched Badlands. But I know my wife, and in a year or two she will miss the road manners of her Audi's she has been driving the last 7 years and this will become my daily. At which point I would probably look at jumping up in tire size. Do you think there will be a noticeable change either on road or off? We spend a lot of time in the mountains and deserts in Utah, but not typically doing any real extreme rock crawling.

 

[Vigor]

Stupid question probably but, which feels less like driving a truck?
4.27, or 4.7?
Guessing 4.27 right?

 

[Lakelife36]

Do you live where there's large hills or mountains? Do you ever plan on going to 35's? Do you ever plan on towing a trailer or loading your Bronco heavy? If you said YES to any of these things then you want the 4.7

Downside is that at highway speed you turn a few hundred RPM higher.

Those ratios are so deep that I wouldn't worry about 4.27 vs. 4.70.for towing. Keep in mind most trucks run less than 4, or 4.10 for towing packages. I believe the Ranger uses 3.73.

 

[HoosierDaddy]

In what scenario do you get to choose between 4.46 and 4.7?
Badlands 4cyl, auto or manual?
Squatch or not is a MUCH larger decision than just gears.

 

[dgorsett]

How noticeable do you all think the performance change from the 4.46 to the 4.70 if someone jumps from 33" to 35" tires. Between the M/T's being impractical for someone driving up Little Cottonwood Canyon 60 times a ski season, and the fact that this will start as my wife daily driver (she didn't want 35" tires), we went with the non-squatched Badlands. But I know my wife, and in a year or two she will miss the road manners of her Audi's she has been driving the last 7 years and this will become my daily. At which point I would probably look at jumping up in tire size. Do you think there will be a noticeable change either on road or off? We spend a lot of time in the mountains and deserts in Utah, but not typically doing any real extreme rock crawling.

Are 4.70's better for 35's? In a perfect world sure. In the real world you won't notice the difference, it's just 5%: 50 rpm at 1000 (crawling) 100 rpm ( cruising or powering a bit off road.)

 

[WCP-82]

I ordered a Badlands and spent several days trying to figure out if I should go Sasquatch to get the 4.7 gears. Most of my Google searches turned up Jeep forums. Many commenting were talking about gearing up to run 35" tires. They say to go to 4.10 or 4.56. They also aren't mated to a 10 speed trans. I figure the 4.46 will run 35" tires just fine. I have no plans to go to 37". That's where I see the 4.7 being a plus.

For me the 33" tires will fit better with my everyday use and the 35" tires would be more for looks. I wasn't a fan of the optional wheels for Sasquatch and went with the standard BL wheels. I figure I can make a decision when the tires wear out and then start shopping wheels and maybe go 35". By that time any modifications, if needed, will be well known and there will be a better selection from aftermarket companies.

 

[Gamecock]

I ordered a Badlands and spent several days trying to figure out if I should go Sasquatch to get the 4.7 gears. Most of my Google searches turned up Jeep forums. Many commenting were talking about gearing up to run 35" tires. They say to go to 4.10 or 4.56. They also aren't mated to a 10 speed trans. I figure the 4.46 will run 35" tires just fine. I have no plans to go to 37". That's where I see the 4.7 being a plus.

For me the 33" tires will fit better with my everyday use and the 35" tires would be more for looks. I wasn't a fan of the optional wheels for Sasquatch and went with the standard BL wheels. I figure I can make a decision when the tires wear out and then start shopping wheels and maybe go 35". By that time any modifications, if needed, will be well known and there will be a better selection from aftermarket companies.

The Jeep forums are of zero help, as the final ratio is only 1/3rd of the equation. You’re not factoring the transfer case gearing or the transmission gearing...so 4.10 could be way taller or way shorter. Pay no attention to that because it’s apples and oranges.
That said, most of what you said otherwise is valid. I want to be able to go to 37s without regearing, so 4.7 is a must have...and they are better for 35s.

 

[WCP-82]

The Jeep forums are of zero help, as the final ratio is only 1/3rd of the equation. You’re not factoring the transfer case gearing or the transmission gearing...so 4.10 could be way taller or way shorter. Pay no attention to that because it’s apples and oranges.
That said, most of what you said otherwise is valid. I want to be able to go to 37s without regearing, so 4.7 is a must have...and they are better for 35s.

I am new to this and didn't know all the factors involved. I reasoned from everything I read that the 4.46 would be able to handle 35" tires and the 4.7 would be able to handle the 37" tires. It appeared to me that Ford gave a baseline gear ratio to one up without much issues and I think you just confirmed this.

 

[CalvinT]

Explain what you mean by more “Mechanical advantage”. I’m trying to decide if I want to spent the extra $$.

Think of having a longer lever. Engine doesn't have to work as hard.

 

[telenerd]

I had my 2 door Sasquatch Bronco up to 101 mph the other day. The RPM was only about 2500. Just a FYI. Still felt like I could go faster.

 

[RHeinz]

First off, this thread title has bothered me for a while. The bronco is 4wd, so this concerns both the front and rear axle ratios which have to match or you will have issues when you shift into 4wd if not before that.

Drag on a car varies with the square of the speed.

https://ecomodder.com/wiki/Road_Load_Equation
https://auto.howstuffworks.com/question497.htm
http://www.virtual-car.org/wheels/hybrid_road_load_model.html

In my experience crawling a manual transmission wrangler with a 4:1 transfer case and 4.10:1 axle gears, fuel injection can make it very touchy. It can get so bad that it's difficult to smoothly modulate the gas while offroading at say 3mph while crawling. That's why it's usually easier just to let it idle and crawl. Maybe ford will do something about this in the bronco to smooth out the throttle input while crawling. I know it took a lot of practice in my 2015 wrangler rubicon to keep from bouncing when doing rough offroad in crawling gears.

Most wrangler folks prefer going to 4.88 or 5.13 gears when they go 35" or larger tires.

Automatics are totally different due to the slipping that happens all the time. If you don't offroad much, having the right gears for the tires will not matter as much, but you will accelerate faster with lower gears.

More info on gears and carriers with pics: https://www.crawlpedia.com/thick_gears.htm

Good post!

My 2.7L Badlands SAS with the 4.7 gearing gets around 15-16 MPG at 80 MPH. Slow down to 65 MPH and the gas mileage pushes 21 MPG.

The difference is mostly due to aerodynamic drag and only perhaps a tiny difference due to mechanical inefficiency.

 

[HoosierDaddy]

My 2.7L Badlands SAS with the 4.7 gearing gets around 15-16 MPG at 80 MPH. Slow down to 65 MPH and the gas mileage pushes 21 MPG.

The difference is mostly due to aerodynamic drag and only perhaps a tiny difference due to mechanical inefficiency.

Watch your boost gauge also.
Myself and others have noticed that dropping down a gear(raising RPMs) will keep the motor out of boost while maintaining speed and the fuel mileage increases.
I've manually calculated this over several longer trips and dropping from 6th to 5th, thus raising RPMS to around 2700 was the sweet spot at around 78 mph.
Trying to use 6th just bogs the motor down significantly which forces it to boost and it SLAYS the fuel mileage.
ECO/Boost , choose one.

2.3/manual/4.46/35's

 

[TCC]

I have 315 KO2’s on a OBX non-SAS (2.7L, 4:46). I have a place in the city and one in the mountains so spend a lot of time traveling between the two. I don’t rock crawl but we’ve taken some pretty hairy backwoods trails and never felt the Bronco didn’t have enough power to turn the 315’s. I’m also averaging 21 mpg for 11K+ miles where as most SAS owners I’ve read are posting 16-18 mpg, some as low as 14. Of course this is probably a combination of the gearing, the Goodyears, and how they drive.

 

[ILoveToDrive]

There is a bit of misinformation in this thread. I don’t think the 4.7 axle gearing will *necessarily* change the fuel economy number people care about; highway MPG’s. The 10th gear on the auto trans is so tall, my guess is that you’ll only ever been in 10th gear if you are on perfectly flat highway with the 4.7 gearing. With the lower gears, especially the 3.73, and the 32” tires, I would bet 10th gear will be basically unused. (It sounds like the ranger does use 10th gear pretty handily based on what I’ve read, but the ranger runs 255/65r/17’s which are a decent amount smaller and lighter than the 265/70r17’s that are on the 3.73 equipped Broncos. Base notwithstanding)

Where the 4.7 is going to be killer is in city driving since it will accelerate so much faster. YMMV.

I have the model you’re 23 Badland Sasquatch, with the 4.7 differential. Now I understand why I feel no need for a pedal commander or a for performance tweak. Even with the 2.3 L engine, I find the acceleration to be more than adequate in all situations… City, winding roads, high speed highway. It also explains why my gas mileage is not seeing 20. The 4.7 rear with the larger 35 tires, definitely has an impact on fuel consumption.
but, in terms of acceleration and speed performance, I’m completely satisfied with the Broncos performance.

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