3.55 vs 4.10

[Bebo]

Question....looking at new truck....currently f250 crewcab, 3.55, 4wd, short bed. New vehicle looking at 2017 f350 dually longbed, 4.10 gearing....much larger payload for my 355RK 5er. Both trucks 6.7 diesel. Question is what should I expect with different gearing. Changing vehicles due to being way way over weight....was ill informed when bought rig, salesman said had plenty of truck with 250.....different topic. Thanks

[first time 5er]

where you live 4.10 is the way to go. Fuel mileage will be lower but you'll feel the difference going up the mountains. I have the same truck. no complaints here

[Bebo]

I currently average about 16 to 17 combined driving....not towing and about 19 hwy unloaded...with 5er attached with 250 average about 9.5....should I anticipate big differences or small amt ya think....making the change, just want realistic ideas....i hate salesmen....they will tell ya anything

[rhagfo]

Depends on what you are towing. 12,000# to about 15,000# 3.55 with a six speed auto will do fine. If heavier than 15,000# get the 4.10’s.

[Bebo]

Would say am below 15....never taken to scales..need to do that

[sourdough]

With a 4.10 expect a lot "livelier" truck; ie; quicker acceleration, better towing. On the other hand, expect higher rpm's when driving a specific speed and the ensuing lower mileage. Pulling a large load with a 3.55 puts a lot of load on the engine and makes mileage decline. The 4.10 on the other hand makes the work easier on the engine with a heavy load so would hopefully either give you a gain or at least be as good as the 3.55. I've not had the 4.10 and 3.55 in the same truck. I have had the 3.55, 3.92 and 3.73 in the same truck and all got better than the 3.55 under load.

[JRTJH]

Here are the 2017 Ford specs,
DRW 3.55 GCWR 36,000 - - 4x2 28,400, 4x4 27,900
DRW 4.10 GCWR 40,000 - - 4x2 32,000, 4x4 31,900

Your trailer has a GVW of 15,000 pounds, you'll never be close to either the GCWR or the max trailer rating. If you're looking at the "conventional dually" then the 3.55 will serve you well and save you some money in operating expense. With the power developed by the 6.7 diesel engine, you'll likely never get into a situation where you'd downshift below 5th gear towing up any hill on the interstate system. People tow with the 3.55 with trailers in your weight range all the time and I'd never heard anyone complain of wanting more power or better gearing.

The 3.55 gearing puts the engine RPM in the "sweet spot" (1800 RPM) at 66 MPH, the "ideal towing speed" for interstate travel. The 4.10 gearing puts the engine RPM at 2100 RPM at 65 MPH, somewhat more noise for the same speed.

If you're looking at the "max tow package" dually, then it only comes with the 4.30 gear ratio and would be "overkill" for your weight trailer.

[Bebo]

Came across TV that I like, has lots of features I like....including price....just happened to notice difference in gears....and not sure of what all differences to expect...i do appreciate the feedback....gonna pose question to dealer about finding similar TV with 3.55....unless I am wrong seem like way to go....but....always potential to upgrade to toyhauler in 5 to 7 years when grandkids are a possibility....that makes me think 4.10 maybe way to go for potentially heavier loads....hmmmm

[JRTJH]

If I read the specs from Ford correctly, both the 4x2 and the 4x4 dually diesel models are limited by the frame attachment points to fifth wheel hitches with a maximum of 27,500, so all of the trailer weights above that are "fluff to beat GM and RAM".... I wouldn't want a truck with 4.10 gearing and the diesel. It sounds louder than running my existing truck in 5th gear at 70MPH. I wouldn't want to listen to that noise all the time just so I could cruise at 65-70 MPH.

But, they do make that gear ratio because some people prefer it. Difficult choice, if you're looking at a 25K trailer in the future, but a pretty clear choice for your existing trailer at 15K. Decisions, decisions, decisions..... Let us know which one you buy. They all smell so good when they're new ROFL.

[fourfourto]

I have 4.56 gearing in the H3
I only have a 5 cyl and 4500 lbs towing does the job pulling the 1750rd

[sourdough]

Originally Posted by fourfourto

I have 4.56 gearing in the H3
I only have a 5 cyl and 4500 lbs towing does the job pulling the 1750rd

Ohhhhh boy. Having owned that vehicle for a few years I can only say I limited my grocery buying to 2 bags for fear that I couldn't get across an intersection before the light changed . Now the Alpha 3 was a different story. I will say that it was one of the most capable 4 wheel drives I've owned. It was a little large and boxy but I loved the 4 wheel drive system. It was a joy riding many of the passes around Ouray/Telluride, CO.

[Bebo]

Again, main reason for upgrade is I am way over weight payload/cargo wise with current TV....it pulls my 5er like a champ....but my king pin is 2865#, trying to correct an error and be safe......i am not well versed on gearing, I can read what the brochures say about overall pulling capabilities. Looked at crewcab dually diesel silverados...love the truck but with diesel payload wise I am limited to around 4600 to 4800 for what can find in western NC....by time add additional fuel tank since they only come with 35/36 gallon tank, add myself, spouse, fur kid, and supplies I would be within a few hundred pounds of maxing out truck payload....not towing capacity....i will never max that part out on a 3500 series dually.... don't know what to expect....if anything ....from gear change from current 3.55 with a 2014 F250 SRW and change to 2017 F350 dually both with 6.7 PowerStroke 4x4. Dang trucks are outrageously expensive, want to get it right and be smart about it...next truck needs to be in the fleet for at least 10 years or more. Appreciate everyone's input....will be having dealer look for one with 3.55 as well....and compare some more.

[Bebo]

btw.....payload on new TV am considering is 6540....more than adequate for my needs, no worry about running over weight for my 5er, thus the additional appeal. And as was pointed.out, 5th wheel tow capacity of 27,500...

[JRTJH]

Bebo,

Hopefully Javi will chime in before long. He owned a diesel F205 and upgraded to a F350 dually diesel in 2015. Granted the 2017 is a bit different (lighter overall with more HP/torque) so it would be more capable than his 2015. I don't know which gear ratio he has, but he's towing a 12-13K trailer, so he can tell you from experience the differences in towing capability between the F250 and the F350 dually. I think that's your biggest question at this point, if I understand your posts.... He'll be able to give you some "sage" advice.....

[Bebo]

Yep....been looking for sound opinions of experience from the usual suspects.....if fuel economy isn't that much different and can't find a similar TV with 3.55 will probably go with it. My current 250 rolling down the highway under load has minimal noise....and I go at safe speeds....not in a hurry.....just trying to do it the right way, being safe and smarter....as I have seen said in various ways....because it can pull it does not mean ya should pull it....

[travelin texans]

Just to clarify, any of the big 3 trucks are good choices. As example, my '13 GMC with Duramax/Allison with 373 gears has plenty of power, great acceleration, & towing my 16.5k 5er the sweet spot is 1700 rpm/68 mph making 8.5-11.5 mpg depending on terrain/wind & 15-18 mpg empty & the newer models have more hp & torque.

[larry337]

Either rear axle will work. I have 3.55 in a 17 f350 and I average 9.5-10 pulling 12k @ 70mph. A 4.10 would probaly cost you 1mpg from what I have read. I have plenty of power and rarely drop to 4th gear. 3.55 drw is rated to 27500. The 3.55 is awesome but no doubt the 4.10 is better. Just depends on whether you value mpg or performance. Leftover 17 may not leave you an option. You don't know what you don't know so you're likely to love either one you end up with. My first choice would probaly be 3.55 but I'd buy the 4.10 if that's all they had. And IMHO a 4.10 would have more resale appeal, not necessarily a higher price but more in demand and a quicker sale.

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[Tinner12002]

Originally Posted by Bebo

I currently average about 16 to 17 combined driving....not towing and about 19 hwy unloaded...with 5er attached with 250 average about 9.5....should I anticipate big differences or small amt ya think....making the change, just want realistic ideas....i hate salesmen....they will tell ya anything

Nope, that's pretty close to where I'm at across the board with truck in sig running 4.10s. I can actually get around 21 running empty at 55mph. Not sure the 3.55 is even available in a DRW, even if it was, not one I would want! Lower gears like 4.10s are going to make your equipment last longer and will keep your RPMs a little higher so your not lugging going down the road, your mileage will be negligible in my opinion.

[jsmith948]

I usually stay away from discussions regarding gearing - but - FWIW - gas rigs and the older, lower torque diesels needed lower (higher number) gearing. The newer diesels are high torque rise engines that are designed to run at a lower rpm. I don't think you "need" 4:10 gearing. The 3:55 ratio will do the job especially when paired with the 6 speed auto.
As a comparison: When I first started driving big rigs in the mid seventies, many of the trucks were equipped with 13 and 15 speed transmissions or compound transmissions (read main box and brownie) with as many as 20 gears. The shift points were about 250 rpm apart because the engines were designed to operate between 1800 and 2100 rpm. These were 850 cubic inch 350/400 hp engines that developed around 400# of torque. The rear end ratios were most often 4:10 to 4:55 here on the west coast. The flatland truckers would run 3:90s for more top end speed. With the development of high-torque-rise engines, the Spicer 9-speed became the more common transmission because the shift points (or splits) were longer - 500 rpm or more due to the engines' ability to pick up the next higher gear without lugging. Gone were the days of the twin stick semis (darn - they fun to drive). But I digress... the modern high torque rise diesel powered pick ups just don't need super low gears unless pulling EXTREMELY heavy loads. To think otherwise is just old school, IMHO. If you aren't expecting to take off with "a cloud of tire smoke" acceleration, 3:55s are the way to go.

[larry337]

Originally Posted by jsmith948

I usually stay away from discussions regarding gearing - but - FWIW - gas rigs and the older, lower torque diesels needed lower (higher number) gearing. The newer diesels are high torque rise engines that are designed to run at a lower rpm. I don't think you "need" 4:10 gearing. The 3:55 ratio will do the job especially when paired with the 6 speed auto.
As a comparison: When I first started driving big rigs in the mid seventies, many of the trucks were equipped with 13 and 15 speed transmissions or compound transmissions (read main box and brownie) with as many as 20 gears. The shift points were about 250 rpm apart because the engines were designed to operate between 1800 and 2100 rpm. These were 850 cubic inch 350/400 hp engines that developed around 400# of torque. The rear end ratios were most often 4:10 to 4:55 here on the west coast. The flatland truckers would run 3:90s for more top end speed. With the development of high-torque-rise engines, the Spicer 9-speed became the more common transmission because the shift points (or splits) were longer - 500 rpm or more due to the engines' ability to pick up the next higher gear without lugging. Gone were the days of the twin stick semis (darn - they fun to drive). But I digress... the modern high torque rise diesel powered pick ups just don't need super low gears unless pulling EXTREMELY heavy loads. To think otherwise is just old school, IMHO. If you aren't expecting to take off with "a cloud of tire smoke" acceleration, 3:55s are the way to go.

Well said, and as a trucker, I agree. With 925 ft/lbs of torque the new f350 dually with a 3.55 is rated to pull 27,000lbs. Moore than any rv'r would ever need and it'll hardly ever drop a gear to maintain speed. 3.73 isn't even offered anymore and a 4.10 bumps the tow rating too 30,000. These new trucks are amazing. Tow/haul mode, set the cruise and forget it.

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