How important is 3.73 axle for large trailers?

[CaptOchs]

I've been trying to find an Exp to replace my 2003. Apparently it needs $2700 worth of work and isn't worth fixing. My trailer is a 2018 Keystone Springdale 270LE. Empty weight is around 7000#. The 2003 did fine and it has a lower tow capacity than any of these. I don't really tow further than 300 miles. I'm in NY, so no extreme mountain towing.

2015, Limited $25,984. 3.31 axle, 84k
2015, Limited $30,984. 3.31 axle 43K,
2015, XLT EL (tow pkg) $20,995. 3.73 axle 95k,

Thoughts?

 

[ynpmoose]

I would not skip out on the 3.73 and tow package. Tow package also gets you the trans cooler and upgraded radiator, which is important. I think you are gambling otherwise, considering this is a fairly heavy trailer.

 

[ynpmoose]

Actually, pulled the latest towing guide. 3.31 is only rated for 6000 lbs, 3.73 is 9000 lbs. I don't think you have a choice.
https://www.ford.com/cmslibs/conten.../guides/19Towing_Ford_Expedition_r1_Dec21.pdf

 

[powerboatr]

3.73 is a no brainer,

 

[CaptOchs]

I was going off the Ford towing guide. Looks like both the 3.31 and 3.73 can tow 9200# if they have the tow package. I have seen enough 3.31's with brake controllers to know that they have the HD tow. Was wondering if anyone has the 3.31 and comfortablely tows around 7000#. https://www.google.com/url?sa=t&sou...FjAAegQIARAB&usg=AOvVaw1l_FrLEgli0gjdBuCRXwP6

 

[Tomct]

Try car gurus web site
Found a 2017 XLT with 37 k miles
With tow package for 25 k
But has 3.31 gears

 

[LRNAD90]

Actually, pulled the latest towing guide. 3.31 is only rated for 6000 lbs, 3.73 is 9000 lbs. I don't think you have a choice.
https://www.ford.com/cmslibs/conten.../guides/19Towing_Ford_Expedition_r1_Dec21.pdf

I'm pretty sure all the '15-'17 Limiteds, as well as the 202a package XLTs, have the HD tow package, even though most have the taller 3.31 gears. So its not the Gear ratio that sets the maximum towing capacity..

All (4wd) EL's have the 3.73 gears and a limited slip rear, but I hardly ever see any of the short wheelbase Expeditions with the 3.73 gears. And something else you may want to consider is that the more wheelbase the more stability you will have with larger/heavier trailers, so maybe the EL is the way to go..

Of course, the more weight you pull, the 'nicer' it is to have the lower gears, but not needed to get the tow rating. And you could get a 5-star (or similar) tune for more power if you needed..

 

[JasonH]

I was going off the Ford towing guide. Looks like both the 3.31 and 3.73 can tow 9200# if they have the tow package. I have seen enough 3.31's with brake controllers to know that they have the HD tow. Was wondering if anyone has the 3.31 and comfortablely tows around 7000#.

I have a 17' EL with 3.31 gears and HD tow. My trailer is 7,000lbs. It tows fine, no issues with power at all. Most of my towing is on relatively flat ground, but I haven't had any issues with the minor hills I have encountered towing between Houston, Dallas, and San Antonio. we haven't done anything with severe grades like Colorado yet, but it usually goes uphill in 5th gear driving around 60 - 65 mph.

 

[rdlangston13]

I have a 2015 Limited with the 3.31s (I thought they were 3.15) and I pull a 6900 trailer just fine. Just lock out 6th gear. We tow this 400-500 mike trips annually with 6 people in the car.


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[Boostedbus]

The 3.73’s also help in tow haul mode to engine brake in deceleration. They aren’t just more torque/power.

 

[JasonH]

The 3.73’s also help in tow haul mode to engine brake in deceleration. They aren’t just more torque/power.

Good point, I haven't done any driven any major hills yet so have not relied on the tranny to control speed on a decline. Are any of the other gear ratios altered when a shorter final drive is used? The vehicles all get the same MPG rating...but all things being equal shouldn't the shorter final gear lower mpg?

When TFL Truck tested the Expedition towing they said it required several brake applications to control downhill speed. Why not just downshift to reduce the need for manual brake application?

 

[Langer]

I was going off the Ford towing guide. Looks like both the 3.31 and 3.73 can tow 9200# if they have the tow package. I have seen enough 3.31's with brake controllers to know that they have the HD tow. Was wondering if anyone has the 3.31 and comfortablely tows around 7000#. https://www.google.com/url?sa=t&sou...FjAAegQIARAB&usg=AOvVaw1l_FrLEgli0gjdBuCRXwP6

I have a 2017 XLT 4x4 with 3.31, and added trans cooler, brake controller, 7-pin, etc, and tow my 28’ boat with no issues. The boat is 6200# dry, trailer 1000#. With equipment and gas I’d imagine I’m close to max capacity. Positives exist for the better gearing, but definitely not problem for the truck.

 

[JasonH]

I've noticed during my current drive from Houston to FL that the transmission will downshift agrressively in tow/haul mode to help control speed. It was dropping into 1 - 3 gears on hills and bridges when going downhill.

 

[coolzzy]

At speeds above probably 20mpg, tow haul will only downshift you to 2nd gear on a slope, and the ecoboost does not have enough displacement to engine brake very well. 2nd gear will still roll downhill at 50mph with a trailer behind you at roughly 4k rpm and that's as far as I've let it push before using the brakes. It would roll faster still if you let it...

 

[johnboneske]

I have a 2017 XLT 4x4 with 3.31, and added trans cooler, brake controller, 7-pin, etc, and tow my 28’ boat with no issues. The boat is 6200# dry, trailer 1000#. With equipment and gas I’d imagine I’m close to max capacity. Positives exist for the better gearing, but definitely not problem for the truck.

don't forget there is a HUGE difference between pulling a boat and a camper. Boats are aerodynamic, campers are bricks... I used to pull our 26' Rinker with a minivan without any issues when going a short distance and it weighed around 6k. Pulling a 7k TT with my Expedition is a big difference.