2019 F350 gearing

**Oldcow** · 02-19-2020, 11:38 AM

I currently tow a 34" TT with a 2010 Tundra. I think I am ready to sell the Tundra in anticipation of retirement (3 years out) and pull the plug on a 2019 F350 DRW. 376th is in plan to replace the TT. There seems to be great deals to be had on this truck in Canada right now, up to $20K off on the higher trim models. What I am finding out is that they all come with 3:55 gearing. I have never towed heavy so this is all new to me. Are we good with this gearing for the 376th? I see others towing with the 450 with 4:33 gearing (I think). Is 3:55 adequate with today's new engines? And yes I know I will get all kinds of opinions

, hopefully I hear from others with the same or similar combo.

Oldcow

**Txfivver** · 02-19-2020, 12:20 PM

Your user name makes me laugh every time I see it lol. You would be fine with 3:55 gears but 4:10's would probably be better for a 376. My truck has 3:55's and it has no trouble pulling my Solitude at 16500 pounds. The 376 will probably be 2-3000 pounds heavier when loaded and the terrain you'll be towing in can make a difference. Long story short you would be fine with a 3:55 geared truck but 4:10's would probably tow a 20k pound GVW trailer better. Good luck and enjoy that awesome trailer when you get it!

**Oldcow** · 02-19-2020, 01:14 PM

Haha yes that name does make many chuckle. We plan to travel all over North America. If I want a 4:10, I would have to order the truck. I want the right truck the first time, but I also like saving money... I also agree that it would be fine but 4:10 wold be better. Much difference in fuel economy when not towing? This truck will mostly be used for towing so that question may be irrelevant.

Many people with a 376th pull with 3:55?

Oldcow

**kevinpo** · 02-19-2020, 01:37 PM

Hello,
The different ratios will change the maximum trailer weight you can pull by (3-4,000 lbs). 4:10's will put less strain on the transmission which is another factor to consider. For the model you are considering I would advise to get the 4:10's. The fuel economy is not much different between the 2 ratios you have listed.

Regards,
Kevin

**Airrace** · 02-19-2020, 02:49 PM

Something else to think about is the 2020 Fords with the 10 speed trany. I am running 3.55's with my F0350 DRW and 2018 310 (about 15,500) and have no trouble on the west coast I-90 & I-80 passes. I really liked the 3.31 I had in my 2015 F-350 SRW.

**Oldcow** · 02-19-2020, 03:15 PM

Originally Posted by Airrace

Something else to think about is the 2020 Fords with the 10 speed trany. I am running 3.55's with my F0350 DRW and 2018 310 (about 15,500) and have no trouble on the west coast I-90 & I-80 passes. I really liked the 3.31 I had in my 2015 F-350 SRW.

The deals right now are on the 2019's. Good to know you have no issues. Have you traveled much in elevation?

Oldcow

**CoChris** · 02-19-2020, 05:47 PM

I have a 2017 F350 SRW (not a dually) with 18" tires and the 3.55 rear end. It pulls my Solitude 310GK (typically 13,900# total for trailer, 22,700# total combine weight) all over the Rockies (I live in Northern Colorado) just fine. Often times I drop all the way down to 4th gear on long, steep pulls

. That is what the transmission is for. I tow at 65 MPH. A taller rear end (3.55 vs 4.10 or 4.30) will put a little more strain on the drive shaft and rear end (for the same load and speed), but the new Dana rear ends are very stout, especially the M300 in the dually. That should not be an issue. The 17" tires on the F350 dually will be a little shorter so roughly equivalent to a 3.71 rear end with 18" tires. In the end, it is what you are happy with. I like the lower RPM (easier on the engine) and better gas mileage with the 3.55 when running empty.The 3.55 and transmission is plenty for my trailer. A 376 is a fair bit heavier. If you do a lot of towing in the mountains with a fully loaded 376th you may prefer the 4.10. I would not go to a 4.33 (remember the F450 has 19.5" tires and I think they are quite a bit taller, which effectively lowers the rear end ratio). If you are only towing trough the Rockies (or Grapevine) a few times, I would stay with the 3.55.

Chris

I will add that at 65 MPH (my towing speed) and the 18" tires w/3.55 rear end I am just over 1,600 RPM (1,620). The torque peak for 2017 6.7L power stroke is between 1,600 and 1,800 RPM. I am not sure where the torque peak is for the 2019 PS, but I would try to match your typical speed in top gear to be in that peak torque range.

**Airrace** · 02-19-2020, 05:50 PM

Passes on I-90 from Seattle to Billings. I do watch the oil temp and when it hits 240+ I will back out of the turbo some and slow down. Also in Yellowstone NP (solo) and Beartooth Pass (solo)(11,000 ft) I tend to only do around 65 with the trailer so am used to being passed. Both of us retired so no hurry to get anywhere today

There are tons of bells and whistles so pick what you want and get a good price. Good Luck

**Dirt4Dan** · 02-19-2020, 05:55 PM

With the 3:55's the 376TH trailer weight is well under the maximum loaded trailer weight specified by Ford. I also like the 6 speed transmission since it has proven to be very durable. 2020 is the 1st year for the 10 speed in the SD.

**Oldcow** · 02-20-2020, 03:27 PM

Thanks for the input guys. I used the search function (which I should have done in the first place) and see that there is lots of discussions on this topic. Now, I am scratching my head considering the sharper turning radius and larger brakes of the 450. And, there certainly are lot's of opinions on that. This is exciting and mid boggling at the same time.

Oldcow