Importance of axle ratio

I am new to this forum.  I have owned two different travel trailers,a hybrid, and a bunk house.  I would not say I have a ton of experience as an rv?er.  I have used two different tow vehicles one with each trailer.  I used a half ton suburban for the hybrid and a 5.4 excursion 4x4 for the bunk house.  I have used the excursion for multiple trips of 1,200 miles and one of 2,500 miles pulling my BH.  It is not fast.  It struggles for power.  It gets the job done, does not break down, it controls the trailer awesome.  It has low miles for the age, fits my family of six plus a dog easily. 

My question to all who have experience is this:

Should I regear from the 4.10?s to 4.56 or 4.88 to better cope with the mountains while towing?

Or should I

Sell it and find a v10 version?

I get that a v10 would be better but I trust my X.  It has been well maintained.  I?ve owned it long enough that I have history with it.  Bottom line is that I trust it.  I feel that when you find a machine that works it?s hard to gamble with another.  All X?s are getting old.  I hate to start over with unknowns.  I use the X for towing the BH and exploring forest service roads here in Colorado.  I don?t daily drive it because I have a dedicated work truck.  We do tend to pile up in it every vacation.  I would love better mileage but don?t really care too much if I never see that in this truck.  I mostly want a more enjoyable towing experience.  Mild hills are fine.  Flat road is easy.  What leads me to believe lower gears will help is that I can more easily maintain 70-75 mph than I can 65 mph.  It is an rpm power band thing.  I don?t like the idea of those speeds with a 6,000+ lbs trailer.  I?d prefer 65 mph for both safety and fuel reasons.  I have test driven v10 excursions and like the idea but all I have tested have issues that mine has never had.  I just don?t know if the power is worth inheriting someone else?s problems versus modifying a vehicle I know and trust. 

I run stock sized tires.  I?m okay with taking my time.  Any thoughts?  Which way would you go and why?

If you don't have enough horsepower now when downshifting the transmission, changing ratios won't help.  Get enough horsepower and drive under 65 MPH.

Your current ratio should be just fine.  Seems you have a horse power issue.

I think you answered your question throughout your post. Despite some shortcomings you like your X and do not want get rid of it. You are afraid a new more powerful X will be wrought with problems. Problems not found in the current X. Go with your gut. Better yet, do what I do. Ask the wife. If she says go with a new X and things go south it won't be your fault.

A friend has a F350 V10 Triton. It's not the wonder machine you are thinking it might be. Gas mileage is absolutely horrible. 10mpg, without towing, is considered good by him. Horsepower is probably ok, but he generally ends up slowing down considerably on climbs to keep RPMs relatively low. Maybe others with V10 have better results, but I'd steer clear of a V10 based on his experience.
By way of comparison, my GMC 6.6L diesel gets over 20 mpg freeway mileage not towing and between 12-13 mpg towing. I don't have to slow down when climbing either. I imagine Ford diesels get similar mileage and performance.

Let's see: You want more power, but you don't want a new truck. Sounds like a dilemma to me. Changing the rear axle to 4.56 will increase the power at the rear wheels, but will hurt the fuel economy when not towing. Is that acceptable?  It should help with acceleration and hill climbing, though.  I checked the Towing guides but apparently Ford did not offer anything higher than the 4.10 axle in the 5.4L Excursion, so no tow capacity numbers are available for those axles. Also, it appears that the optional high ratio axles back then were a 4.30 and a 4.80, not the ones you mentioned.

That Excursion ain't gonna last forever, so at some time you will need to get over your fear of getting a different vehicle. Is now the time to bite the bullet? If you decide it is, let's further discuss what trailer you have and what vehicle specs will be needed to tow it with the sort of performance you desire.  A quick scan of some later year Ford towing guides shows a 2013 Expedition 4x4 with the 5.4L V8 and heavy Duty Tow Package, rated for up to a 9000 lb trailer.  And that's with either the 3.31 or 3.73 axle, so probably better fuel economy too.  That's well above the old Excursions.

Hammster said:

A friend has a F350 V10 Triton. It's not the wonder machine you are thinking it might be. Gas mileage is absolutely horrible. 10mpg, without towing, is considered good by him. Horsepower is probably ok, but he generally ends up slowing down considerably on climbs to keep RPMs relatively low. Maybe others with V10 have better results, but I'd steer clear of a V10 based on his experience.
By way of comparison, my GMC 6.6L diesel gets over 20 mpg freeway mileage not towing and between 12-13 mpg towing. I don't have to slow down when climbing either. I imagine Ford diesels get similar mileage and performance.

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My 2013 duramax only ever got 14 on the highway not towing and 8-10 towing my 5 er at 55mph my current ford while still new only gets 8 towing. I dont really drive it much without the trailer so i cant comment there. We are also 3500 feet above sea level which makes a difference with the thin air.
One of the reasons i picked this truck was because it had a 3.55 rear the available 4.10 is a beast off the line but crappy mileage the gm with the 3.73 is a great compramise between the 2

If the poster changes ratios to what hes suggesting  mileage will go to crap and highway speeds will drop to about 30 mph lol

Another idea to replace the existing power plant with a new one which is relatively inexpensive if the rest of the vehicle is in good shape

I only have 120,000 miles on my X.  I?ve owned since it had 60,000 miles.  It was the wife?s car until I got her a newer one.  This is where it gets weird.  I bought her a 2011 expedition el with the heaviest tow package.  Has 3.73?s.  On paper it is rated higher towing limit.  It has a 6 speed transmission.  It should do a better job.  In real life it does not.  I live in the Rocky Mountains of Colorado.  I find the expedition pulls fine on the flat but not as well on grades.  Also the excursion is built like a tank with the same running gear behind the engine as the bigger motors.  It?s not that the excursion sucks.  It does a great job at breaking and controlling the trailer.  Absolutely awesome in those regards.  Better than the expedition el hands down is those areas.  What got the gearing idea going is that coming back from YNP last summer on I-80 I could much more easily keep 75 mph than I could hold 65 mph.  75 mph is too fast to be safe towing IMHO.  I would be happy to be able to hold 65 mph while towing.  I just don?t drive it enough when not towing to really care about gas mileage empty.  Most of the time I drive a 2015 Mercedes Sprinter 2500 4x4 for work.  The excursion just sits waiting for family fun.  I know the excursion won?t last forever but I figure it?s got a lot of life left.  I just want to get the most out of it.  Lower gears will move the strain from the transmission to the axles and they are more than up to the task with a small block and stock sized tires.  I?m looking for those who have done it.  Don?t want to drop a couple grand in a theory but base it off of experience. 

I put 2015 f250 towing mirrors on the X and it is worlds better than the stock non towing mirrors.  That is another issue with the expedition there are no towing mirror extensions specifically made for it.  Owning and having used both vehicles the 5.4 2v X is a more comfortable experience with my trailer which is somewhere north of 6,000 lbs.  my expedition is rated for 9,200 lbs but doesn?t climb the hills around me like my X does so it must be the 3.73 vs 4.10 ratios.

If I had the budget I would do a Cummins/Allison conversion and never look back

The Cummins with an Allison would make a real truck out of it.

newfurrows said:

The Cummins with an Allison would make a real truck out of it.

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If I had the budget I would fly first class and stay in 5 star hotels.

Oldgator73 said:

If I had the budget I would fly first class and stay in 5 star hotels.

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;D  ;D  ;D