3:73 or 4:10 looking for advice

[Sixpac2]

Want to order a 04. 5 3500 dually 6 speed. I tow a 14-15K 5th wheel and combined weight current truck (another 3500) with 5th and dogs wife ect. come in at 21000 to 22000lbs. I would like the lower gearing for non towing situations but dodge says combined gross is 21k. The 4:10 23k. NOW THE QUESTION Any real world experiences, opinions, pro and con, difference in RPM say at 60-65mph, fuel mileage (or way to figure out RPM). Are the Gross Combined hard numbers and if not what can be damaged. THANKS ,I don't mean to go on just want all info can find. Thanks again.

 

[Dean Upson]

If you are going to tow a 15k fiver you should get tthe 4:10s, imo and an exhaust brake. I get 10. 5-12. 5 towing, less if bucking a wind or in the hills and more if it's flat with a tailwind(not very often). 2000rpm about 62mph. Just look at the towing guide for that kind of weight, the 4. 10s give you another ton vs: 3. 73's.



Dean

 

[BillGotthelf]

I have the exact setup you are talking about. A 03 dualie 4 door 6 speedwith the 3. 73 rear. I pull a 36' fifth wheel around 15k. I get 12. 3 mpg at 60 and 11. 4 at 65. On a long run at 70 I got 10. 8. With the 6 speed and the 3. 73 you won't have any problems finding the right gear. You will get slightly better mileage at higher speeds not towing with the 3. 73 rear also. Definatly get an exhaust brake, this is my first one and driving in the mountains is great and I'll never have a truck without one again.

 

[BillGotthelf]

Oh by the way Dean and I don't agree on anything anyway.

 

[Sixpac2]

what is your gross combined ?

 

[Dean Upson]

Originally posted by BillGotthelf

Oh by the way Dean and I don't agree on anything anyway.

Gross combined is what your truck and trailer loaded with all aboard weigh.



Dean

 

[EB]

Everyone has their own opinions about that but I pull a large gooseneck hauling oilfield equipment. Gross weight of truck and trailer empty is 15,200 lbs. My normal load will be an additional 12 to 15,000 lbs on the trailer. I run 3. 73 gears and have never had any problems getting started or going up and down hills. My loaded mileage runs 9. 5 to 11. Just pulling the trailer will get about12. 5 to 13 mpg. I do that every day and I run a lot of miles. You wanted actual experiences, that's mine.

 

[How'dHeDoThat]

4:10's here

I got the 4:10's in my 04 4x4 and the milage is 14. 5 to 15. 5 so far (only have 1200 miles)(not really broke in yet)



I got 4:10's because I plan on putting 40's on it and wanted to have gears for it. Till then trips to Houston are HIGH RPM





My 01 is 355's and 36" tires and is WAY high geared. On the dyno I did 158 mph at 3550 rpm's. 70 mph is 1525 rpms.



Pullin real heavy or going with big tires 4:10's



Cruisin with nothin more than the 315 tires or light pullin 373's



just my comments on it.



James

 

[draymorris]

My opinion - it depends on how much you like shifting. I hear both sides when it comes to MPG. If you want to stay at higher speeds, you may have to go to 5th more often with 3. 73 and that could hurt your milage more than just having 4. 10's. I travel trailer catches a lot of wind, similar to the loads of hay that I hual every weekend. I know that the wind can cost me milage real easy, but the worst thing as that is cost me time - I have had days were the wind made me stay in 5ht at 55 MPH for many miles. I think 4. 10's would not be affect this way - I know a man who does the same thing I do with hay, he says he can put his in 6th and stay there every trip - he has an 01 with 4. 10s.



My loads are way too heavy to compare apples to apples with an RV, but I thought I would throw in my opinion.

 

[DCaswell]

My . 02 is I wish I had 3. 73. My GCVW is often 25k to 30k and it is amazing what hills I can pull is 6th but I could cruise in 5th on the hills @ 60 & would have better rpm when empty. When these Goodyears wear out I will go up one tire size to compensate

 

[EMD-Run8]

Bruce Mallinson (Diesel Injection of Pitt. ) has a good article on gearing. It's worth reading. Gearing a diesel is different than gearing a gasser (almost 2x the torque and 1/2 the rpms). 3. 73's with 6spd and 245's already run 2000 rpms at about 66 mph. The engine's torque peak is at about 1400-1600 rpms. I just don't see how 4. 10's are any help or are even needed?

 

[RMcCulloch]

I went with the 4. 10s for the higher GCWR and am (usually) within the 23K when pulling our 5er.



The 4. 10s and the 48RE balance out to be about the same overall gear ratio as the DEE's 6th gear with 3. 73s. [That O/D 4th is TALL!]

 

[Sarge]

I just bought my second truck with the 4. 10 rearend, and thought briefly about getting 3. 73's. However, I have towed a lot thru some long grades, pulling a 12K tall fiver. The 4. 10's will keep you in 6th, at 60mph to 70mph, depending on how heavy your foot is. All I know is that when I hit a grade, I just hope the others are smart enough to stay to the right... ... ... . Sarge

 

[InThinAir]

I think James hit it on the head. If you are planning on super sizing the tires then get the 4. 10's if you are gonna stay stock then you should be in great shape with the 3. 73.



Along those line I know that the 11. 5 rear end is in a couple of different flavors of trucks. 3500 srw and drw, these trucks have different sized tires stock. Which tire actually gives you the 3. 73.



---Doug

 

[Fred Swanson]

Look at it this way. If you don't plan on running 19. 5's on the DRW, then you are very limited on tire choices(taller). The 4. 10's will no doubt pull it easier, yet at a slightly higher RPM at a given speed. Mileage may or may not be a factor.

If you plan to pull all the time, then go with the 4. 10's. If you are close to max on the weight, go with 4. 10's.

The 3. 73's will do the job just fine, the RPM drop between them is not too much, like the 4. 10 to 3. 54 drop.

I pull 15K with my gooseneck, and only on slower steep climbs do I have to downshift. On normal up and down grades, no downshifting. This again will factor in where you live and where you haul the trailer.

Do get an exhaust brake, you'll never regret getting it.

 

[Greg Boardman-RIP]

Originally posted by Fred Swanson



I pull 15K with my gooseneck, and only on slower steep climbs do I have to downshift. On normal up and down grades, no downshifting.

Give that thing a little fuel and you'll make it up any hill...

 

[Fred Swanson]

Alright Greg.



If I can maintain normal speed, and not have to worry about tossing my load, you know I don't have to downshift. I have no problem powering up any hill at or above posted speed limits.



Yeah, more power, that's what you need to catch up to me.

 

[Greg Boardman-RIP]

Fred,

Don't you mean more $$$$$$$$$$$$$$$ Not power. I need a clutch first, where's the dual disk? Then the heat is an issue. Twins? Lets see, TST box? I guess I am at a financial limit. I just don't have another $6000 at the present time. Looks like I will have to wait for the Marines to come home from Iraq and tattoo for 16 hrs a day for a month. Then it will be no problem to keep up. Nothing like planning ahead. Greg

 

[klenger]

The tire sizes on the SRW and DRW 04 trucks all produce almost the exact (within 1%) same diameter and revs / mile as the 265/75R-16 on the 2nd gen trucks, so camparing gear ratios is valid between models and years.

 

[InThinAir]

Klenger, so I am not sure but I thought that the sizes were



2500 stock 245/70 17 diameter approx 30. 5

Upgrade 265/70 17 diameter 31. 6



3500 SRW Stock 265/70 17 diameter 31. 6



3500 DRW All 235/80 17 Diameter 31. 8



I know that is not a lot of difference but is about 5% from stock.



Correct me if I am wrong but they all reference the 3. 73 or 4. 10 ratio. I am just wondering if we are all a little taller than the actual ratio advertised.



---Doug