3:73 or 4:10 in 16 3500 DRW

[dward]

I'm coming up on 1 year owning my 15 3500 4x4 SB Aisin and think it's by far the best truck I've ever owned.
Haven't had one issue in the 8k mi.
I bought this truck as it was going to be my DD and use to tow a toyhauler. I went with the 3500 in anticipation of adding a camper which I did, a small Lance 8'.
I ended up buying a Jeep for a DD and sold the TH. I want to start travelling and want to go back to a bigger camper which will require a DRW.
Truck will be 16 Tradesman, 4x4, DRW, CC with Aisin.
I plan to go bigger on the tires, maybe up to 35s and will be carrying a 5k lb camper and towing my Jeep or maybe an enclosed trailer around 5-8k lbs. I don't see using the truck much without either the camper or towing.
I also want to keep my options open for a larger 5th wheel down the road. 15-18k lb max.
Based on my needs, would you go with 3:73 or 4:10?
My thinking is because it won't be driven much without a load and the larger tires, 4:10 may be best.
How much difference in RPMs at 70 mph between the 2. 70-75 would be as fast as I would ever go.
It's bitter sweet selling my truck, but I'm only getting $3k less than I can get a 16 DRW with the same options for from Dennis Dillion. $11k off sticker.

 

[Deleted member 995608]

You answered your own question. Go 4:10 and be done.

 

[Dieselnerd]

You answered your own question. Go 4:10 and be done.

I agree, you might as well have the maximum towing ability. Gives you a wider range of fifth wheels to look at in the future. The fivers always seem to be getting heavier, not lighter.

 

[Newsa]

I suggest to go with the 4:10. I changed my stock 17 inch chrome wheels out for some stock 18 inch wheels. Someone was selling their stock 18's on ebay, so I got va good price on brand new mounted tires on wheels with installed TPMS sensors.

I have the 3.42 diff, & I notice a difference. In fact I may switch back to the 17's when towing. The 18's are fine when not towing.

I think the outside diameter of the wheels increased 2 inches because I added 1 inch on the rims and another 1 inch on the tires when going to the 18's.



I don't have the automatic and can adjust my shifting to account for the larger diameter wheels. But with the automatic, your truck will come programmed for whichever differential is installed. You might want to see if the dealer can reprogram for the larger wheels?

I wonder if there will be a warrantee problem. Because with larger wheels, your odometer won't read mileage correctly?

 

[Cummins12V98]

I would say 4:10's no matter so you don't limit your self in the future. 4:10's especially if you are dead set on taller tires! I tow a combined 32,500# with the Aisin and 4:10's and would not consider anything else.

 

[mpaulson]

There's a reason that they rate the 4.10 truck reasonably higher than the 3.73, so that extra capacity will never hurt and only aid in more enjoyment using the truck loaded as you will for most of the time and it will reduce the stress on the drivetrain as well for durability sake. Especially if you want to play with tire sizes, 4.10 is the only way to go.

 

[Newsa]

There's a reason that they rate the 4.10 truck reasonably higher than the 3.73, so that extra capacity will never hurt and only aid in more enjoyment using the truck loaded as you will for most of the time and it will reduce the stress on the drivetrain as well for durability sake. Especially if you want to play with tire sizes, 4.10 is the only way to go.

What do you mean "rate it higher?" Higher load capacity? Or consumer rating?

 

[mpaulson]

The 4.10 has a higher tow rating therefore they intend it to better suited to pull more weight due to reduced driveline stress to get the load moving. Looking on RAM.COM, switching between 3.73 and 4.10 basically changes the tow rating by 5000lbs, so it's intended by the manufacturer to be suitable to move more weight. That's all I'm implying. It would be even more over capacity in the OPer's given load and future potential possibilities and perform that little bit better, that's all. I did a change from a 3.73 up to a 4.56 in my last truck and wow! It was like I was starting out in low range, 24,000# didn't even require throttle input to start rolling compared to when I had the 3.73 in the same truck with the same load. So 4.10 provide the same effect, but not as extreme of course.

As for the OP question on the rpms see the chart below.
This chart is for the Aisin AS68RC used in the earlier cab and chassis, but the two O.D. ratios are the same. So you can see for your self what RPM's you will be at for any given speed and gear. With the AS69RC that is in the new trucks have lower first gear ratios I'm pretty sure.

 

[jacknife]

I pull 15000 loaded 3500 mega cab with a 50 gal tank .Truck weighs 9600. 342 rears with the 370 hp 800 torque and it pulls great. With a 6 spd Aisen 373 will pull great whether it is 15000 or 18000. Why run extra RPMS burn more fuel for very little if any pulling increase .

 

[dward]

Thanks for the good advice, thought it was going to be unanimous but 7 out of 8 is close.
My local dealer has 2 trucks set up how I like with 4:10 but listed $5k more than Dennis Dillion who only has 3:73, but with negotiation and not having to fly to Idaho and drive home, I should be close. I also bought my 15 from them so that shoud count for a few $.
Dillion had 2 nice Bighorns but they came with 3:42. Not sure who would want that tall gearing in a DRW?

 

[Cummins12V98]

"Not sure who would want that tall gearing in a DRW?"

I can tell you from personal experience owning a 11 HO DRW with 3:42's that if I chose anything besides 4:10's it would be 3:42's WITH AISIN trans. Fact is the 3:42's in 5th is the same rpm's as 4:10's in 6th. I towed 29K combined with the 11 and the ONLY issue was getting the load rolling. With the 3:42's and Aisin you would get the load rolling, good rpm's at 60 and great solo mileage.

So to me the 3:73's are a no go.

 

[Newsa]

"Not sure who would want that tall gearing in a DRW?"

I can tell you from personal experience owning a 11 HO DRW with 3:42's that if I chose anything besides 4:10's it would be 3:42's WITH AISIN trans. Fact is the 3:42's in 5th is the same rpm's as 4:10's in 6th. I towed 29K combined with the 11 and the ONLY issue was getting the load rolling. With the 3:42's and Aisin you would get the load rolling, good rpm's at 60 and great solo mileage.

So to me the 3:73's are a no go.

Why would both 3:42 & 4:10 be better than 3.73? Isn't 3.73 between the two?

For 5 grand cheaper, i change my vote to 3.73.

This is based on the extra low gearing in the low gear of Aisin

 

[dward]

The $5k difference is just the advertised internet prices. I'm sure I could get it pretty close if I figure airfare, fuel, hotel, food and 2 days of time.

 

[SnoKing]

Ron "Cummins" has a point about the RPM and gear at ones comfortable towing speed. My 2001.5 towed great at 63MPH in OD at 2K RPMs, trying to tow at 55 sucked, as 3rd was to low and OD to high.

We will be towing to Arizona soon and will be able to get a good feel for towing 12,400 pounds with a truck that will weigh 8600-8800 ready to tow. In the three short 100 mile test tows it seems the 5th gear in tow haul is going to get the job done very well towing 60-63, and she still has the long legs to cruise at high speed bob-tail. And I have gears for towing slower now when required, without racing or lugging the engine. I think RAM got it right for the SRW trucks with 3.42's!


OP's only wild card is his desire to install larger diameter tires. Working with the tire/speed/rpm charts he should be able to figure out if 3.73 put him between desired gears or put him smack on what 3.42's do now. Which is not a bad place at this weights.

SNOKING

 

[Newsa]

It was difficult enough to find a G56. I'm glad i didn't have to sort through a bunch of 4.10's & 3.73's. As it was the closest G56 with SRW was 4 states away

 

[SnoKing]

We drove home 1400 miles to get color, no sun roof, Laramie with buckets, 3500, 4x4, Aisin, KEYLess, park view and sense, and 11K+ off! Had air miles to get there!!!

SNOKING

 

[Newsa]

Your "Cherry" looks like she was worth the drive.
I hadn't seen mine or driven it, just put a downpayment on it and told them to ship it.
I had test driven a dually G56 down here, so i knew what i wanted. Wifey vetoed the dually

 

[dogbreath650]

What would be the difference (roughly) in fuel mileage towing the same load (say 13K) between 3:42, 3:73 and 4:11 with the Aisin trans?

 

[Cummins12V98]

"Why would both 3:42 & 4:10 be better than 3.73? Isn't 3.73 between the two? "

Thought I explained that.

 

[gsbrockman]

So to me the 3:73's are a no go.

Don't knock'em.....till you've had some windshield time with'em. :-laf

I sure would not leave 4,500 lbs of towing capacity and 4,500 lbs of GCWR on the table just because of the 3.73's (3.73's vs 3.42's).

Likewise....if I were teetering on being in the next level of GCWR....I'd have no reservations at all going with 4.10's. The 4.10's "shine" more over 3.73's (5,300 lbs more towing capacity and 5,300 lbs more GCWR) just like 3.73's "shine" more over 3.42's.

Still trying to figure out where most everyone comes up with "3:42" instead of 3.42 and "3:73" instead of 3.73 and "4:10" instead of 4.10....