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F250 3.73 to 4.30 axle ratio

carlislefamily2
Explorer
Explorer
I have a 2017 F250 4x4 crew cab, 160" wheel base, 6.2l gas, 3.73 gear ratio. I am trying to see if having 4.30 axle ratio gears installed will make much difference regarding 5th wheel towing. I noticed that the Ford Towing Guide shows an increased max loaded trailer weight increase of 2,500lbs with the 4.30 gears as opposed to 3.73 gears. Also, if anyone knows the average cost of this gear swap, that would be helpful. We are looking at going from a trailer to a 5th wheel and could use the extra max loaded trailer weight that the different gears should provide.
Thanks....
50 REPLIES 50

noteven
Explorer III
Explorer III
Here's a video of a 4.30 ratio 7.3 gas V8 Ford pulling an 18,000lbs trailer up Loveland Pass (aka The Ike Gauntlet! omg!) at nearly 60mph.

The 10 speed does not do much shifting once the rig settles in to pulling the grade.

F250 - 18,000lbs trailer

Grit_dog
Nomad III
Nomad III
This is getting blown out of hand.
I said $3k, knowing this is the upper end for HD 4wd gear swap from quality shop and best quality gears.
Then someone equates it to $5k and says equivalent diesel only costs that much....
Do you guys even think before you type, or just perpetually Overly pessimistic Or just plain wrong?

No, I personally wouldnโ€™t consider a gear change, especially on a new truck. Unless a very specific situation with no other options. Like you gotta have 37s on a 3.42 Ram towing heavy. Itโ€™s one thing on an old truck. But on a new truck, itโ€™s just too easy to sell it and get what you want or need.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ€ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

ppine
Explorer II
Explorer II
goducks10 wrote:
ppine wrote:
Five thousand dollars for a gear swap is just about exactly what it costs to buy a diesel instead of a gas engine.


Add $4000-5000 to that.
The diesel option for a ford is $10,495.
Ram its $9300


Still worth the money. My diesel is still going strong from 2002 so I am out of date. The extra cost to buy a diesel is quickly paid back in performance and longevity. How much is a gas truck with 200 k miles worth?

noteven
Explorer III
Explorer III
$5000 allows you drive by and wave privileges at the diesel service shop. Actual repairs are more ๐Ÿ™‚

StirCrazy
Nomad III
Nomad III
dodge guy wrote:
StirCrazy wrote:
Grit dog wrote:

Yes it will help, but will it help $3000 worth? .


3000ish or more is just the strt, lower fuel milage for the rest of the trucks life on empty or towing. accellerated enging wear from higher RPM.

Best way to do it is big torque low rpm in my opinion, if you could aford it adding a turbo set up would be the most efficent way to go but has issues in its own. or if its time to buy a new truck soon anyways put up with it and get a diesel. (sorry didnt see that it is a 2017, so i guess thats not an option unless your leasing and its time for a trade in. some times dealerships will give you a good buy back on a relitively new truck, might be somthing to check into. the 6.2L is not realy a tow monster motor to start with.

Steve


Obviously you have never done this swap and know what it can do! It will not get worse mileage towing, in fact it will go up approx .5 mpg towing. In town non towing driving it will go down, but marginally. But non towing city/hwy will go up. Solo hey you may lose .5 mpg. Itโ€™s not going to wear out the engine any faster. If it does the only difference is hours or converted maybe a couple thousand miles during the engines life. So if the engine were to last 200k miles with 3.73โ€™s it may only last 198k with 4.30โ€™s.

Love how people comment on things they know nothing about!



Actualy I have severl times over the years. if you drive normal with fule economy in mind when towing and drive a bit slower on the highway taller gears will give you a tiny bit more milage but how many people can make that change and stick to it... the place they will save money is starting from a stop, it will be eaiser to get it running and on bigger hills on highways where you would have had to shift down before, but overall on flat lands every time I did a gear swap I lost overall milage.

as for shorter enging life it can be minor or significant depending how you use it and how well you maintain it. but generaly if the same person takes care of the vehicle the same befoor and after you will lose a bit of life, its just a factor of more reveloutions over the same distance. newer motors are better and like you said could only be a couple k miles, but if your not one to keep up on maintance and you do a lot of highway driving it could be a very significat differance.

Steve
2014 F350 6.7 Platinum
2016 Cougar 330RBK
1991 Slumberqueen WS100

goducks10
Explorer
Explorer
ppine wrote:
Five thousand dollars for a gear swap is just about exactly what it costs to buy a diesel instead of a gas engine.


Add $4000-5000 to that.
The diesel option for a ford is $10,495.
Ram its $9300

ppine
Explorer II
Explorer II
Five thousand dollars for a gear swap is just about exactly what it costs to buy a diesel instead of a gas engine.

noteven
Explorer III
Explorer III
The majority of engine wear occurs from cold start to approx 140F coolant temperature.

Todayโ€™s trucks are overdriven to such a low cruise rpm they need 220+ amp alternators to keep the gadgets powered at 1200 engine rpm ๐Ÿ™‚

As for the 6.2 Ford it pulls pretty decent for a gasohol engine.

I donโ€™t think the current generation of diesel pickups enjoy the emission system pains previous generations did.

A 4:30 ratio truck will still out truck a 3.73 all else being equal.

dodge_guy
Explorer
Explorer
StirCrazy wrote:
Grit dog wrote:

Yes it will help, but will it help $3000 worth? .


3000ish or more is just the strt, lower fuel milage for the rest of the trucks life on empty or towing. accellerated enging wear from higher RPM.

Best way to do it is big torque low rpm in my opinion, if you could aford it adding a turbo set up would be the most efficent way to go but has issues in its own. or if its time to buy a new truck soon anyways put up with it and get a diesel. (sorry didnt see that it is a 2017, so i guess thats not an option unless your leasing and its time for a trade in. some times dealerships will give you a good buy back on a relitively new truck, might be somthing to check into. the 6.2L is not realy a tow monster motor to start with.

Steve


Obviously you have never done this swap and know what it can do! It will not get worse mileage towing, in fact it will go up approx .5 mpg towing. In town non towing driving it will go down, but marginally. But non towing city/hwy will go up. Solo hey you may lose .5 mpg. Itโ€™s not going to wear out the engine any faster. If it does the only difference is hours or converted maybe a couple thousand miles during the engines life. So if the engine were to last 200k miles with 3.73โ€™s it may only last 198k with 4.30โ€™s.

Love how people comment on things they know nothing about!
Wife Kim
Son Brandon 17yrs
Daughter Marissa 16yrs
Dog Bailey

12 Forest River Georgetown 350TS Hellwig sway bars, BlueOx TrueCenter stabilizer

13 Ford Explorer Roadmaster Stowmaster 5000, VIP Tow>
A bad day camping is
better than a good day at work!

pyoung47
Explorer
Explorer
The is often tricky to get shimmed and adjusted correctly. With reliability and expense in mind, I think that I would just put up with the 3.73 until time for a new truck. I can't imagine anyone as the next owner would want a 4.3 either. A friend of mine tows a rather large designer with the same set up as yours with few issues. It's no diesel, but it works.

StirCrazy
Nomad III
Nomad III
Grit dog wrote:

Yes it will help, but will it help $3000 worth? .


3000ish or more is just the strt, lower fuel milage for the rest of the trucks life on empty or towing. accellerated enging wear from higher RPM.

Best way to do it is big torque low rpm in my opinion, if you could aford it adding a turbo set up would be the most efficent way to go but has issues in its own. or if its time to buy a new truck soon anyways put up with it and get a diesel. (sorry didnt see that it is a 2017, so i guess thats not an option unless your leasing and its time for a trade in. some times dealerships will give you a good buy back on a relitively new truck, might be somthing to check into. the 6.2L is not realy a tow monster motor to start with.

Steve
2014 F350 6.7 Platinum
2016 Cougar 330RBK
1991 Slumberqueen WS100

Grit_dog
Nomad III
Nomad III
I got a set of 4.10s I'll trade straight across for someone's 3.42s or 3.73s!
Even on 35s, with no OD, 69mph = 3000rpms!
Does real good burnouts though! Can roast the tries all the way through 3rd gear.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ€ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

dodge_guy
Explorer
Explorer
Having gone from 3.73 to 4.30 myself, it is worth every penny. When I had the Excursion with the V-10 OD was useless when towing. After I could cruise in OD and it would only kick down on the largest of overpasses. It also stopped bogging down on each shift because the gears made the trans work better. I also gained .5 mpg towing.
Wife Kim
Son Brandon 17yrs
Daughter Marissa 16yrs
Dog Bailey

12 Forest River Georgetown 350TS Hellwig sway bars, BlueOx TrueCenter stabilizer

13 Ford Explorer Roadmaster Stowmaster 5000, VIP Tow>
A bad day camping is
better than a good day at work!

lenr
Explorer II
Explorer II
My opinion--yours will vary
OP has a Ford 6R140 transmission with 3.97:1 first gear. It's hard for me to believe that more launch power is needed. The new Ford 10 speed has 4.615:1 for even more launch. There is no doubt that a higher axle ratio will improve the torque and HP in every single gear, but is it worth the cost? Only the OP can decide if it is worth it to him.