CRXsi

Hello everyone,

I am new to the diesel scene as my current tow vehicle had a little problem and went and blewded up. (GMC 1ton dually 454) Anyways I am highly considering a new 03/04 Dodge QC 4x2 3500 DRW HO. I think I will be getting the 6spd but haven't fully decided yet. My main question is to the choice of rear gears...3.73 or 4.10's? Which would most people reccomend? Both as far as mileage and power. I tow an open deck car hauler...fully loaded around 7,000lbs. I will also probably be putting a camper on the back of the truck as well. With a gas motor I wouldn't have flinched and got the 4.10's however I understand that diesels run at a much lower RPM and am wondering if it is more beneficial to stick with the 3.73's I will be driving some very steep mountain roads however I will also be using it as a daily driver, any thoughts anyone?

Hoss

If you opt for the auto tranny then DEFINITELY get the 4.10 gears. If you go with the 6 speed, I'd still get the 4.10 gears...but the 3.73 gears would work for you as well and would give you an additional 1-2 mpg when empty.

Mopar_Mudder

As said before with the auto 4.10's no question

With the 6 speed and the light about of weight you are pulling I would go with the 3.73's. It will give you the 1-2 mpg boost, and easily pull the amount you need to.

FiverBob

Hey, welcome to the forum. And, after owning a bunch of 454's, I don't blame you going for the Cummins. You will love it.
I have the HO 6 speed with the 4.10. I tow close to 16,000#, so 4.10 was a necessity for me. If I were only towing 7 or 8000, I would have the 3.73. The HO is one tough hauler - - after the 454, you will be amazed. As stated, the 3.73 probably will get better mileage running empty, but around the same running loaded as the 4.10. In fact, the 4.10 seems to give a little better mileage towing really heavy loads.
Either way, you will love it.
Bob

CRXsi

Thanks for the imput so far guys,

I am still undecided as to which to order...It is a tow vehicle after all and I don't want to sacrafice power through mountain passes...but the vehicle won't see this on a regular basis, maybe 1 or 2 times a year. It will tow in the city several times a month but the rest will be unloaded. If the difference is truly only 1-2 mpg then it isn't as much as I thought it might be. Is it really true that top speed would be 80mph? And if so is that really buzzing the motor? The other issue is tranny selection...I have never owned a manual tranny in a truck (All my cars are though!) I have always had problems with auto tranny's no matter which manufactuer and am leaning towards the 6spd. Anyone know what the life expectancy of the clutch is on a truck like this? How have the manuals been holding up? And does this affect my decision in a final drive ratio?

Thanks for any imput once again!

Mopar_Mudder

Well you are looking at pretty much the same truck as mine except yours in a 2 wheeler, not a real truck

Any ways I can tell you that empty running full tank of fuel wtih cruise set at 74 I got 16.7 also just normal running around back and forth to work I get between 16 and 17 also.

Top speed with the 4.10's and 6 speed is around 95 really pushin it. 90 mph is 3000 rpms. I have run between 80-85 for long periods with no problem, even pulling. That does drop your milage down to the 14.5 mpg area though (empty).

I am sure the 2 wheeler will gain you a little milage also. Oh ya I have the Edge EZ box on mine which did help my milage a little, more of a help pulling then empty it seems though.

tmiller24

Welcome CRXsi,
I drag race and tow a 3400# Cuda on an open trailer with 3.55 gears and automatic.I have no problems at all in the Kentucky and Ohio hills,but these aren't mountains. Was pulling a 44ft gooseneck enclosed with the same rig,happily. After saying all that my choice next time will be a 6speed and 3.73. Do miss my big trailer,tho! Tony

BoldtsWagon

6 speed 3.73, automatic 4.11 gears; these combinations have the same final drive ratio. The 0.69 overdrive ratio with the automatic is a BIG step, it needs the 4.11 ratio to compensate.

cumminsho2500

get the auto with 4.10 my truck has 1900 miles on it now and i get 20 mpg on the highway at about 65.....the power is great to

GrandpasRam

Welcome to the board. From the loads and driving type you are talking, the manual 6 sp with the 3.73 is plenty for you; if going with the auto get the 4.10's. One thing I do recommend (only available with the manual) is an E-Brake, especially for the mountains and/or hills.

doug

[quote author=BoldtsWagon link=board=20;threadid=19142;start=0#msg180015 date=1062601125]
6 speed 3.73, automatic 4.11 gears; these combinations have the same final drive ratio.
[/quote]
no they DO NOT. The final drive ratios are 2.72 and 2.83 respectively which is a ~ 4% difference. The 6 speed/3.73 will run 80 rpm lower than the auto/4.10 at 70 mphtrue, but if you are looking for equality in the final drive ratios, the 4.10 "overcompensates" for the automatic's .69 overdrive ratio. Yes the automatics have a 6 percent taller overdrive gear than the 6 speeds. However, the 4.10 axle itself is about 10% shorter than the 3.73, which is why the 3.73/std and the 4.10/auto combos differ by the ~4% mentioned above.

Here's some numbers to help answer the 3.73/4.10 question:

mph, rpm/3.73-std, rpm/4.10-std, rpm/4.10-auto
55, 1634, 1796, 1697
60, 1782, 1959, 1852
65, 1931, 2122, 2006
70, 2079, 2286, 2160
75, 2228, 2449, 2315

you can see why 5ver bob appreciates the the 4.10 6 speed -- he tows very heavy and a lot, and gets the advantage of running over 2100 rpms at 65 mph. Empty, that would be a disadvantage and you'd want to run at 1900. so based on the original question and towing/driving expectations I'd recommend the 3.73/std.

CRXsi

I've been hearing lots of good arguments for both set-ups. My next question would be if I decided to go with a heavier trailer and had the 3.73's would I likely have a lack of power issue? Or would the 3.73's still be OK. As I said before..it is afterall a tow vehicle...but if there is only a small advantage and a bigger advantage with gas mileage then I gots some thinkin to do. I am juust trying to be as informed as possible before I actually order. The general concensus is that the 3.73's would do however if there is any doubt about towing performance later on then the 4.10's may be the better. Remeber I am only used to towing with a 454 auto gasser and I don't really know what to expect from a diesel in terms of power (other than in theory there should be much more!) Again thanks for all your guys comments and please keep them coming!

Mopar_Mudder

Well here is what it came down to for me, I wanted as much pulling power as possible and mileage was a secondary factor. If I have to stop a little more often and spend a little more on fuel I don't care. But I pull a 40' at a GCVW of 30,000# so I wanted everything I can get.

The 3.73s are rated at 21,000# GCVW and the 4.10's at 23,000# GCVW. As long as you stay under that 21,000# rating with 3.73's I think you would be very happy. But if you really don't care what kind of milage you get and flat out just want to pull then get the 4.10's.

Now if I was doing this as a business and making money pulling stuff around then things would change a bit. The better mileage would have the advantage of more money in your pocket.

Another option is the 4.10's with an aux overdrive tranny, if someone wanted to loan me the money for one I would love to try it :

doug

[quote author=Mopar_Mudder link=board=20;threadid=19142;start=0#msg180085 date=1062610346]
Another option is the 4.10's with an aux overdrive tranny, if someone wanted to loan me the money for one I would love to try it :
[/quote]

ooooohhhh, second that motion. And the extra OD gear would be an advantage for the 3.73s as well -- allowing you to run in 5th gear (direct)!

I put 3.73s on mine because its a short box SRW and I don't plan to tow as heavy and as often as some guys do. and I go offroad occasionally and need the manuverability of a SRW. I have a trailer hitch weight limitation of about 2,000 lbs. mudder's advice is very good--look at the trailer weights you plan to have. If its above the 21,000 GCWR then go for 4.10s. But if you're above 21,000 GCWR then you have a pretty big trailer, you'll probably need the extra payload of the duallie (to accomodate the 5th wheel hitch weight) and so all of a sudden you're looking at a 4.10 DRW. that is one bad towing animal.

3.73 and the cummins will put a huge smile on your face compared to the gassers. For very heavy towing, the 4.10 will please you even more for two reasons:

1. The axle itself will put 10% more torque to the ground, from whatever the engine delivers. thats just torque multiplication via gears, thanks to Issac Newton. You'll feel that in your seat-o-pants meter off the line and for slow speed pulls, but keep in mind that it is only 10%

2. In ADDITION to the above, the engine will deliver 10% more horsepower to the wheels (at WOT) because it is developing the same torque but at a higher rpm. this is good when you are trying to maintain 65 mph on a 6% grade...

that is not an insignificant, double whammy. But again, the 4.1 is for creating the ultimate towing animal for large 5th wheel trailers. The cost is higher rpms and lower fuel economy when running empty.

Do some trailer shopping and you'll discover that the larger 5th wheels with bedroom slides require a duallie to accomodate the hitch weight, and you'll be happiest with the 4.10 duallie and the ultimate highway towing animal. If you don't require that much trailer, and want some additional drivability in the truck, you'll be happier overall with a 3.73 SRW (town driving, fuel economy, 4WD manuverability, etc). If you plan to tow a 5th wheel of any sort, don't even consider a 2500 -- you won't be able to pull many trailers (and stay under the published ratings), and the hitch weight will always be a nag. imho, the 3500 SWR is one of the best things DC did with the 3rd gens. Its also the most popular truck in their lineup, according to something I read (I promise it wasn't flapping lips...)

Anyhway, as you can see, once you start upgrading from the 2500 to accomodate heavier trailers, you eliminate one limitation and expose another (take care of GCWR and then GVWR rears its head). it doesn't stop until you reach the 4.10 duallie ;D

doug

you know, CRXsi, I just read your first post again and remembered that you have already decided on a DRW 4x2 truck. Just my opinion, here, but that means you are positioning yourself to accomodate a large tow or tow/haul combination (i.e. camper plus trailer). A 3500 DRW 4x2 truck to me should have 4.10s -- just because if you're going for the duallie you're a self-proclaimed towing nut and you need the best towing animal available. With the 3500 4.10 CTD Duallie you have no limitations (well, you have the best available). Also, consider re-sale. how many folks would want the payload of the dualie but only 21,000 GCWR in a 3.73 when they can have 23,000 in a 4.10. Especially for a 4x2 truck (you're committed to highway towing) -- I'd go 4.10 all the way. A 3.73 axle on a duallie is just one screw short of the biggest, baddest towing animal on the planet. just my opinion of course . nuts to the fuel economy issue -- its only a 10% hit anyway -- does that really matter? and when you're towing the 4.10 may even be a mpg advatage!

I'm of the opinion that a 3.73 on the duallie defeats the purpose of the truck and creates an unnecessary limitation (GCWR is now the limit, not GVWR). that is, you can accomodate any payload or 5th wheel hitch on the planet (well, you get my point...) but such a large payload in a 5th wheel will probably push you above 21000 GCWR. If I was in your shoes and committed to the 4x2 duallie, I'd go for 4.10s. towing animal to the max, man. don't be a wimp

Now then, just to jog your thinking. If you really dont' think you need that much trailer (you can tolerate 21,000 lbs GCWR and the ~ 2000 payload) then as I said before -- re-think the DRW choice. get a 3.73 SRW 4WD truck. its more useful as a daily driver, and hey -- you might want to go offroad or whatever. re-sale will be neutered if its not a 4x4, and consider that the vast majority of SRWs are 4x4s.

Comes down to whether or not you want a towing truck or a do-everything truck. me, I wanted a do-everything truck. It sounds to me like you're after the ultimte towing animal. have mercy, that 3500 DRW 4.10 is just awesome. especially for towing a trailer WITH a slide-in camper.