Which rear axle ratio? 3.73 or 4.10

[phxpsd]

I have a Grand Design Momentum 380TH which has a pin weight of 3700# and overall weight of 18,000#. Going to get a new truck, dually, CTD and the Aisin, which ratio do you guys think would be best? Probably 70% empty driving, 30% heavy towing in steep mountains. I'm thinking the 4.10... Thanks in advance. I know you all are wondering what I pull it with now, but I'll get flamed!!!lol It is a RAM though....

 

[JLandry]

And let the battle begin... :-laf

 

[RUSSELL5000]

OK, for the education of a newby, why would you do other than the 4.10? I know only a third of the time towing heavy in steep mountains, where I think the 4.10 would be advantageous. The other two-thirds of the time empty on the road, but that is why we have a six spend transmission, isn't it?

This answer seems straightforward to me with an 18K trailer and expecting to travel through steep mountain areas - you get the capability you need for the highest requirement.

What am I missing?

 

[EGroeneveld]

I'd choose the 3.73 gears if I was you. 4.10 won't kill you though.

http://www.ramtrucks.com/assets/towing_guide/pdf/2016_ram_3500_towing_charts.pdf

Basically 3.42 gears gets you about 20K of towing
3.73 gets you over 25k
and 4.10 gets you 30K

3.73 will cover pretty much any RV trailer or 5th wheel toy hauler.
4.10 for the guys that haul heavy equipment

100% my opinion.

Also I know with so many western states with 75 and 80 MPH limits MPG factors in my decision to go with 3.73 over the 4.10s

 

[Wertles]

My fifth wheel was that size and weight. I went with 4.10's and it towed great through everything. I do enough lighter towing or empty driving that I wish I had gone with the 3.73's. And I "only" have 850 torque. The new is rumored to be 900 so 3.73 would perform even better. If you want the best towing rig and capability of future heavier trailers, get the 4.10's. You will not regret it.

 

[RustyJC]

We tow a 19,000 lb GVWR 5th wheel, and if I were ordering a 2016 Ram 3500 dually today, it would have the 4.10s, as have my last 2 duallies. With the double overdrive 68RFE and Aisin 6-speed automatics, the 4.10s are perfectly capable of functioning as a good all-around selection for unloaded cruising as well as towing. My usage profile is 90% towing, so that's what I spec a truck to do.

Rusty

 

[Dieselnerd]

The difference in mileage between the 3:73's and 4:10's will not be significant. Different driving styles make a bigger difference than those two gear ratios.

The difference in towing will be noticeable. the 4:10's stay in 6th gear most of the time except on very steep grades. I've always had 4:10's on my towing vehicles so maybe I'm biased. With 4:10's you can stay in the engines sweet spot which is around 1800-2100 rpm's.

 

[Cummins12V98]

When I was towing with my 11 RAM HO Dually I was towing a combined 30K with 3:42's. I would mostly tow in 5th. It was the asme RPM's as if it had 4:10's in 6th. It towed great. I knew from my experience I wanted the 4:10's when I ordered my 15 and 16 39TKSB3 Mobile Suites that will push me to at least 31K combined. Have not towed the 16 yet but did tow the other MS and the difference getting the load moving with the 4:10's and the Aisin was amazing!

GET THE 4:10's!!!!!!!!!!

 

[DGamelin]

I would go with the 410. My 04 had 373 with G5600 and with the double over drive these new auto trans have the rpm are all most the same. I just got a 2015 dully aisin 410 and on the way back from the dealer it got 17mpg at 68mph. 18k is a big load and the more gear the less the trans has to work. The differences between the two gears is only about 200rpm's.

 

[phxpsd]

Well, I got the dually with the Aisin and 4.10's. Thanks for your input. With my 2500 4x4 CC Cummins, my GVW with the trailer and my DW in it, we were at 27,000lbs. The 5th wheel alone is sitting at 17,990lbs. We use our rig for scuba, so when our gear and tanks are loaded, full water and full of gasoline, we will be right at 19,500lbs, the max for the trailer. I love the Aisin, test drove both transmissions and the Aisin is so much smoother shifting. I can't wait to see how it will tow the 5th wheel. I only towed the rig from the dealer to my house and then to our site in a rural area. I don't know how anyone with a heavy toy hauler does it with a 3/4 ton truck. Scared me to thing about a blowout on the road. Anyway, thanks again. I'll post some pics when I get it all put together.

 

[Hoefler]

I had 4.10's in my 2010, the 14 has 3.73's. Towing the same trailer, about the size and weight as yours, I was surprised at how well it did. Running with cruise on, very seldom does it does it downshift. It is amazing how well it will hold speed. Fuel mileage is better when towing, with the 5er I get right at 9.6 for 3,000 miles. With my work trailer, about 6500 pound continuous, 12 mpg driving around the Ozarks where it is always uphill.

 

[Mingoglia]

As was previously said, the new trannies have double over drives. My '15 dually with 4.10 gears in top gear is more or less the same RPM as my second gen dually with 3.54 gears and the NV4500. I'm sure there's an advantage in fuel economy with the newer trucks and the double over drive, but the gearing doesn't hold it back from going down the road at high speed unloaded. I KNOW this, because I got pulled over at 96mph when my '15 was 3 weeks old just north west of Moab. It was an awkward stop because I didn't have a permanent plate, registration, or even an insurance card for the new truck yet. Knowing it was new, he didn't write me up for that. I think I need 4:30 gears to keep my speed down a bit. With that being said, did you know the cruise control can't be set for a speed over 85mph?

 

[Cummins12V98]

I have not tried to top out my 15 with 4:10's. My 11 with 3:42's hit 103, that was it and at only 2,300RPM's.

 

[Mingoglia]

I have not tried to top out my 15 with 4:10's. My 11 with 3:42's hit 103, that was it and at only 2,300RPM's.

My '01 dually would hit 116 at redline. I once got clocked at that speed outside Kingman, AZ. I remember I was coming back from a tradeshow in Vegas and I had my tradeshow booth in the back of my truck. First thing the DPS officer said was, "I didn't realize these trucks could go so fast". I replied with, "they don't, that was a Mirage". He laughed, we talked about offroad racing for a bit, then he handed me a ticket. LOL At least I didn't go to the pokey.

 

[Cummins12V98]

What was amazing about doing 103 in the 11 RAM Dually was the wife did not even know it! With the 98 if I came close to 80 she would look up and say you better slow down!.. It was such a smooth ride at 103. Also it was rock solid.

 

[phxpsd]

These trucks are amazing. For those of us old enough to remember, I can recall doing 100+ in a 1971 LTD and wondering how in the **** I'm going to keep it on the road.

 

[Cummins12V98]

These trucks are amazing. For those of us old enough to remember, I can recall doing 100+ in a 1971 LTD and wondering how in the **** I'm going to keep it on the road.

That brought back memories! I took my drivers ed in a 72 LTD. The teacher kept saying "keep it on the top side of 70" going thru the curves it scared the sh#* out of me!

 

[GBBrown]

I'd choose the 3.73 gears if I was you. 4.10 won't kill you though.

http://www.ramtrucks.com/assets/towing_guide/pdf/2016_ram_3500_towing_charts.pdf

Basically 3.42 gears gets you about 20K of towing
3.73 gets you over 25k
and 4.10 gets you 30K

3.73 will cover pretty much any RV trailer or 5th wheel toy hauler.
4.10 for the guys that haul heavy equipment

100% my opinion.

Also I know with so many western states with 75 and 80 MPH limits MPG factors in my decision to go with 3.73 over the 4.10s

Didn't realize you had to go to a 3500 DRW to get a 3.73 or 4.10. Towing only list 3.42 for 3500 SRW, yet you have the option in the gassers.

 

[Okie-Go]

4.10 without a doubt.

 

[EGroeneveld]

Didn't realize you had to go to a 3500 DRW to get a 3.73 or 4.10. Towing only list 3.42 for 3500 SRW, yet you have the option in the gassers.

Yep a bummer for sure. Ram likely worried about too many ordering a SRW with 4.10 thinking they'll tow a 30k gooseneck equipment trailer.
But for guys that want to lift their truck and install bigger tires it is to bad you can't order 4.10s on a SRW....
I'll stick with a dually cause I carry a heavy slide in truck camper plus tow a toy box at the same time.