Why are 4.10 gears offered?

[RoryTek]

Can anybody say gear splitters? You get the best of both worlds. But of course I don't have one, YET

 

[GWBourne]

I had the 4:10 in my '01 with 6 speed. I miss it, especially when towing. Wish I had ordered it on this '05.

Blu, your truck with 3. 73's is proboly the same ratios as my truck with 6 speed and 4. 10's so long as you have the new ^ trans. being you have an 05 i dunno what one yo uhave as they can be both.



i love my 4. 10's in my 04. 5. i pull 18k when i have my trailer. i have to be nice to it because my tires are not up to snuff, but since i pull short trips right now (4 to 10 miles round trip) i dont worry about it too much. ill be buying some PJ dirt grips for the rear soon. should take care of that problem.



Grant

 

[Trizae]

My 2001 HO 6 Speed had 3. 55 and i was running 315's I could put 8 or 9,000 behind it and run 100mph+ uphill,, and set the cruise at 70 and get 26. 7 MPG empty,,,,,, I really miss that truck If i was going to be towing 15k plus on a regular basis then i pay 45 bucks for the 4. 10's,,, but unless you towing a lot of weight on a regular basis the 3. 55's are the way to go,,, besides a stock 12valve will only run about 91MPH with 4. 10's and a 5 speed,,, My 01 had 120 on the speedo and it would run every bit of that,,,, I realize most people get a little worried about running a 7000lbs truck 120MPH on 35" Mud Terrain tires,,,, But most of us are not most people,,,,,

 

[Blu-meanie]

Grant:

I have the NV5600. That's a fair amount of "stuff" under My Junk link.

Thanks for serving.

 

[klenger]

This question is sort of like asking "why does Dodge offer trucks with black paint". If you don't like it, don't buy it.

 

[Rman]

you run the weight I pull at 1600 rpm and you'll melt the engine down. The turbo simply doesn't produce enough air to keep EGT's from getting ridiculous. If you want to come find some hills just take drive down here for a while. And bring a 16k backhoe with ya!

 

[CKimball]

wow... I guess I am missing sumthin..... I could not imagine what a dog my truck would be if DID NOT have 4:10..... my fiver with Jeep inside 100 fresh,35 gal fuel station etc is 15. 2k#+-... sees every hill UNLESS I am at 70+ this is also true with my 8500k# travel trailer. on the flats i can cruise in od all day (gettin12 to 13mpg)... if I had anything less than that it would drive like the early CTD... . pull all day... at 50mph with nothing in reserve... ... I will say that my truck is a very early 03 with a 47re and a so Calif 235hp/460tq version so if that makes a difference. .



on edit... . empty at 70mph i am at 2200rpm and you really dont need to go anyfaster... i get 17 to 18 mpg at that speed... and I can and do live with that... 4:10s now and will be in the future!

 

[CUMMINZ]

Good for you Mr. Kimball

I gross 22. 5k with my Cedar Creek with 315s and 4. 10s. I took 4500 miles-trip from NC to Colorado/New Mexico in August and filled up/topped off tank 14 times. I averaged 13. 5 mph and pushed the rig the ENTIRE way. If you would offer me a brand new 2006 with 3. 73s I would turn it down.



For you guys with pre-2004 engines, it is a different bear. These new engines like the rpms.



CUMMINZ

 

[NIsaacs]

You guys with anything other than 4. 10s don't know what you are missing!!

What can 4. 10's do that a Cummins powered, NV5600 equipped/3. 55 rear axle truck, not do?





"NICK"

 

[dodgeguy44]

There is not an inline long stroke 6 cylinder diesel that "likes" high rpm. That is a myth. V8 diesels "like" and need rpm and to sell them to the public Dodge campaigns the high rpm myth because people hear it from Ford and GM and believe the Cummins should be the same. I drive a 7. 3 Powdersmoke at work and it needs 2000+ rpm to pull anything but only gets 12 mpg empty and 9. 5 pulling a Bobcat.

 

[tractorseller]

What can 4. 10's do that a Cummins powered, NV5600 equipped/3. 55 rear axle truck, not do?





"NICK"

Pull a big load up a long grade and you'll find out real quick. There is a big difference. Everyday driving and pulling small loads you probably won't notice any difference, and running empty down the freeway you're actually better off with the 3. 55 gears because you can run faster at lower rpm.



A 3. 55 geared truck will still pull the load, but it will downshift much sooner and work the engine a lot harder. I've seen this firsthand. It's a fact. Not a good setup for pulling heavy loads. I wouldn't touch one with 3. 55 gears for what I do.

 

[NIsaacs]

As a 30 year veteran of trucking and logging, all in the western states, I kinda know how to pull heavy loads up hill. The Cummins is rated for 35,000 lbs GCW, so big loads don't phase it. With the NV5600, quite possibly the best manual transmission ever made for a light duty truck, you can down shift, that is what it is for





"NICK"

 

[RustyJC]

Not mentioned yet is the fact that, under equal speed/power requirement conditions, the 4. 10s reduce driveline stresses on all components from the pinion gear forward by (4. 10 - 3. 54) / 3. 54 = 15. 8% as compared to the 3. 54s. That's one reason the engineers rate the 4. 10s for a higher GCWR.



As others have said, if ya don't like 'em, don't buy 'em. It's not worth getting one's knickers in a twist!



Rusty

 

[NIsaacs]

Not mentioned yet is the fact that, under equal speed/power requirement conditions, the 4. 10s reduce driveline stresses on all components from the pinion gear forward by (4. 10 - 3. 54) / 3. 54 = 15. 8% as compared to the 3. 54s. That's one reason the engineers rate the 4. 10s for a higher GCWR.



As others have said, if ya don't like 'em, don't buy 'em. It's not worth getting one's knickers in a twist!



Rusty

Rusty, I agree with your formula, untill you shift into overdrive, then the formula is reversed and actually adds stress. If I were still hauling off highway, with big loads, soft ground, and up hill starts, I would want lower axle gears. In fact lower the better, so as to utilize the upper gears in the transmission and give better startability. However I am talking highway use. The Cummins/Dodge drive train is up to the 15. 8 percent added stress under highway conditions, untill you get into overdrive. Then the lower the axle gears, the more stress you add. Thats why I like the higher axle ratio, makes you shift out of overdrive sooner, the weak link.





"NICK"

 

[RustyJC]

Rusty, I agree with your formula, untill you shift into overdrive, then the formula is reversed and actually adds stress. If I were still hauling off highway, with big loads, soft ground, and up hill starts, I would want lower axle gears. In fact lower the better, so as to utilize the upper gears in the transmission and give better startability. However I am talking highway use. The Cummins/Dodge drive train is up to the 15. 8 percent added stress under highway conditions, untill you get into overdrive. Then the lower the axle gears, the more stress you add. Thats why I like the higher axle ratio, makes you shift out of overdrive sooner, the weak link.





"NICK"

Torque = (5252 x BHP) / RPM



Now, if 2 trucks are running down the highway at 70 MPH in 6th gear (equal power requirements) with the 4. 10 equipped truck running 2350 RPM (like mine does) and the 3. 54 equipped truck running 3. 54/4. 10 x 2350 RPM = 2029 RPM, then the equations shake out like this:



Torque (4. 10 truck) = (5252 x BHP) / 2350 RPM

Torque (4. 10 truck) = 2. 23 x BHP



Torque (3. 54 truck) = (5252 x BHP) / 2029 RPM

Torque (3. 54 truck) = 2. 59 x BHP



For sake of illustration, let's say that the power requirement to pull a certain trailer down the road at 70 MPH is 175 BHP - that's the case for both trucks. Therefore, the engine torque output (both trucks in 6th gear) must be:



Torque (4. 10 truck) = 2. 23 x 175 = 390. 25 lb-ft

Torque (3. 54 truck) = 2. 59 x 175 = 453. 25 lb-ft



With both trucks in 6th gear (0. 73/1 gear ratio), the driveline torques will be:



Driveline torque (4. 10 truck) = 390. 25 lb-ft x 0. 73 = 284. 88 lb-ft

Driveline torque (3. 54 truck) = 453. 25 lb-ft x 0. 73 = 330. 87 lb-ft



(Think of it this way - since the driveshaft of the 3. 54 truck is turning more slowly at 70 MPH, the equation Driveshaft HP = [Driveshaft Torque x Driveshaft RPM] / 5252 says that the driveshaft torque will have to be higher since the driveshaft RPM is lower than the driveshaft RPM of the 4. 10 truck to transmit the same 175 BHP. )



Now, if the 3. 54 truck downshifts to 5th, engine torque will be reduced since engine RPM increased (assuming 175 engine BHP is still required). However, even though the transmission is now in 5th gear, as long as the road speed is 70 MPH, the RPM of the output side of the transmission, the driveshaft (including U-joints) and the rear axle pinion have not changed - they are still governed by Driveline Torque = (5252 x Driveline BHP) / Driveline RPM, and the 3. 54 truck will still have to produce a driveline torque of 330. 87 lb-ft (as opposed to the 4. 10 truck's 284. 88 lb-ft) to transmit 175 BHP at 70 MPH - regardless of what gear the truck is in!



Which is why my previous post referenced driveline stresses.



Rusty

 

[macdaddy]

I cannot believe Dodge offers 4. 10 gears. These Cummins engines have plenty of low rpm torque to keep the rpms down when towing and make significant milage gains with a lot less engine wear.



I would like to see a range between 3. 08 - 3. 73. Nothing lower than 3. 73... ... ... it's just not necessary!



My truck(below) has 3. 54 and a 5 spd and it's way too low geared... ..... 2100 rpm at 110kph(70 mph) 15 mpg towing. My 94 had 3. 54 and automatic... ... ... . 1800 at 110kph, 18 mpg towing the same trailer, much better milage, less rpm, and less engine wear. With the choice I would put 3. 21 gears in my present truck and I know the milage would come up substantially.



That's my RANT for today. :-{}[/QUOTe



You grocery haulers never give it a rest



Mac

 

[NIsaacs]

Rusty, again I agree with your formula, awesome post. I can understand it very well, however I would not be able to point it out like you did, but I understand every thing you said and know this to be a fact. However, your original post said, "everything forward of the pinion" not just drive line. Then my response was yes, but the Dodge/Cummins is up for it with nary a whimper. The only weak point is overdrive. I also, have not berated the 4. 10, only defending the 3. 55. With the NV5600, downshifts are part of its usability, not just up shift to 6th and kick back. So... ... . buy 3. 55's and use that puppy





"NICK"

 

[RustyJC]

1. Point taken on the "everything from the pinion forward" - even though I did say driveline stresses earlier in the sentence, it's admittedly somewhat ambiguous.



2. I might buy the "weak 6th (overdrive) gear" argument if we were talking about NV4500s (5th being OD). Not with the NV5600, however.



I'm just pointing out why the engineers bless the 4. 10 gears with (in my case) 1,500 lbs of additional GCWR. Like anything else, ya pays yore money and ya takes yore choice.



Rusty

 

[NIsaacs]

Overdrive is always the weak link in a manual transmission. How much so in the 6-spd. we really don't know yet and it might take a jillion miles. But when it go's it will be overdrive related. Maybe not the gears themselves, but the heat and stress on bearings & shafts. Thats why all the big trucks have moved to direct drive trannys and high axle gears. Case in point, why the little four speed trannys of yesteryear lasted so long, (direct drive).





"NICK"

 

[RustyJC]

Back to my prior post, though. The 4. 10 truck, for a given speed and horsepower requirement, will be transmitting less torque out of the transmission (284. 88 lb-ft in my example) to the driveline than will the 3. 54 truck (330. 87 lb-ft in my example). Therefore, if I accept your argument regarding a "weak" 6th gear for the sake of this discussion, the transmission isn't loaded as heavily torsionally with the 4. 10s as the output side of 5th would be with the 3. 54s, so the factors would tend to offset each other.



At the end of the day, the proof is in the performance. I've not heard of a rash of 6th gear failures in 4. 10-equipped NV5600 trucks towing heavy, have you?



Rusty