New Ford 3.55 rear end

[vinnyv99]

Looking to buy a 2018 Ford F350 King Ranch dually . Has everything I want . Checked the rear end and it has the 3.55 in it. I thought the 3.73 was standard but I could be wrong . I am pulling a fifth wheel trailer that is 16000 lbs . Just wanted to know what people thought and hear from people who may have this set up . These trucks are alot of money and want to make sure I cover all my bases . Thanks for any input

[Palmetto]

keep looking till you find a 4.10

https://www.tfltruck.com/2018/02/ask-tfltruck-ford-f350-dually-rear-axle-ratio-get-towing-camper/

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[TX03RUBI]

Looking to buy a 2018 Ford F350 King Ranch dually . Has everything I want . Checked the rear end and it has the 3.55 in it. I thought the 3.73 was standard but I could be wrong . I am pulling a fifth wheel trailer that is 16000 lbs . Just wanted to know what people thought and hear from people who may have this set up . These trucks are alot of money and want to make sure I cover all my bases . Thanks for any input

I’ve pulled a lot more than 16k with my 17’ 350, and haven’t needed any more. If I were pulling it regularly I’d look for a 4.10, but just occasionally I’d stick with the 3.55.

[RyHolub]

I think you’d be ok with it like he said, occasionally. I pull my 16k pound fifth wheel occasionally with a 2017 f-350 SRW with the 3.55 gears.


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[vinnyv99]

What kind of gas mileage are you getting with the 3.55. I know that might be an advantage

[bboswell]

3.55 was the old standard, in single wheel trucks 3.30 is becoming the new standard.

Hopefully the DRW’s are staying at least 3.55

3.55 does fine on stock tires but I sure wish it had 3.73’s for my 36” tires. . I wouldn’t want 4.10 though.

I tow at +/- my 350 SRW’s legal limit several times per year on a 13 hr round trip haul, I run the posted speed + 3, truck does fine unless I have a really long uphill grade and the oil/trans temps will get up past MY comfort zone but not high enough to throw any warnings. It stays in 5th a lot on these pulls.

[TX03RUBI]

100% stock I was seeing 16-18 highway, and 14-15 in town. My SRWs Limit is 21k. I’ve had a hair over 21k on it, and was running 37s at the time. It didn’t have any issues.

[Fordnandez]

I would wait till the 2020 come out. They are going to have 10 speed transmissions and I bet they will match or beat the Cummins 1k torque. All of this is going to come at a cost though.

[WItoTX]

The transmission will make up for the taller gearing. I wouldn't stress about it too much.

[TX03RUBI]

I would wait till the 2020 come out. They are going to have 10 speed transmissions and I bet they will match or beat the Cummins 1k torque. All of this is going to come at a cost though.

I bet the discounts on the 2020s will be almost nonexistent for a bit, and the discounts on the 2019s will be pretty hefty though. Enough that I’d stay looking at the 2019.

[muzzlebrake]

As long as the transmission gears ratios are matched to the rear end gearing it should not be a problem. Most trucks will actually handle more than what is advertised. There is a built-in safety margin to protect the MFG from warranty claims and other legal issues. I would be more worried about the brakes handling the load than I would gearing.

[Fordnandez]

I bet the discounts on the 2020s will be almost nonexistent for a bit, and the discounts on the 2019s will be pretty hefty though. Enough that I’d stay looking at the 2019.

Agreed. I am surprised how little they are coming off the sticker since the new body style came out in 17.

[Fordnandez]

As long as the transmission gears ratios are matched to the rear end gearing it should not be a problem. Most trucks will actually handle more than what is advertised. There is a built-in safety margin to protect the MFG from warranty claims and other legal issues. I would be more worried about the brakes handling the load than I would gearing.

The trucks can handle WAY more than what the manufacturer says. However if you are in a wreck or something you can be in big trouble with the law and your insurance company can leave you high and dry. I am always shocked when guys post pictures on FB and say that they are pulling at 33k load with their F250. It is pretty much publicizing that you are breaking the law.

[Mike Murphey]

I have a single axle 2018 F-350 with a 3.55 rear end. I get around 20 MPG on the highway if I keep it below 70...get about 18 when I'm over 70....I pull a trailer once or twice a year and the mileage will go to about 10-12....It all depends on how often you hook up a trailer if the 3.55 is worth it to you....

[RyHolub]

What kind of gas mileage are you getting with the 3.55. I know that might be an advantage

Today on about a 200 mile trip I think I was getting around 16.5 some city most highway around 75ish


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