3.42 or 3.73, What is your opinion???

[RVTRKN]

After following this thread for awhile, it is time for me to chime in. The gearing choice is your preference if the options exsists. But lets clarify some issues.



1) The stress on the 3:42 is greater, regardless of gearing ratios inputting to the drive shaft than the 3:73, and the 3:73 has a greater stress than a 4:10.



2) The G56 or auto in choice, does not change the stress.



3) The best option that I CHOSE was the 3:73 because my truck is used as a service vehicle in city traffic and when in the tow haul mode I have a low enough gear to take less stress than a 3:54 or 3:42.



4) The 3:42 is too tall and should only be a choice if your only going to be at GVWR, and tow only once a year, but I caution you on towing anytime with it.



The options were only 3:73 or 4:10 when I ordered my 07 C&C, so I chose the ratio with more stress on the rear end. But I also had a 94 2500HD gasser with the 3:54 that I towed with and the gears were to tall when climbing a grade heavy, which caused a lot of unwanted heat from the auto trany. In my opinion the 3:73 is a perfect compromise for economy and towing. If your going to tow heavy all the time, get the 4:10, if your 50/50 towing/city get the 3:73.



In the overall picture a 4:10 can save you money in fuel if you tow heavy all the time, less stress, less RPM's due to easier climbing or pulling, and the 3:73 when pulling heavy you must chose a lower trany gear to do the same work, thus running higher RPM's burning more fuel. But if you chose the 3:73 and tow 50/50 then the savings while you drive in the city will make up the difference.





Now you know your choices, and it is yours. Good luck with whatever you pick.





FWIW, I don't like the 3:73 when towing heavy in the flat regions of California/Oregon, due to the 55 MPH speed restrictions at low RPM's, in my case with the G56, in 6th. There is no power when you climb, even a small incline unless you down shift, then your RPM's are too high. :{

 

[DPKetchum]

Well said!

 

[sabersix]

Gentlemen, the 4. 10 gear is not a factory option for a 2009 3500 with the G56 manual transmission.



Therefore, using your logic/argument/experience I guess you'd recommend the 3. 73 gears...

 

[RVTRKN]

Gentlemen, the 4. 10 gear is not a factory option for a 2009 3500 with the G56 manual transmission.



Therefore, using your logic/argument/experience I guess you'd recommend the 3. 73 gears...

If thats only available and you don't have a 4:10 installed as an after market then sounds good to me. If your ordering a 3500 C&C you have 3 choices (1) 3:42 (2) 3:73 (3) 4:10

 

[IBarr]

Is that final o/d with the newer version of the G56 or the older version. The final drive was changed in them. It was that the final drive and 3. 73 was equivalent to the auto final drive and 4. 10s not 3. 42

That's with the newer 0. 74 ratio, the older one was 0. 79:1.

 

[Cattletrkr]

2) The G56 or auto in choice, does not change the stress.

Stress on the rear end, no. But the 6spd AUTO has 2 overdrives, so even towing in 5th you're still in OD. Better than towing in 6th, but not as good stress-wise as towing in direct.

FWIW, I don't like the 3:73 when towing heavy in the flat regions of California/Oregon, due to the 55 MPH speed restrictions at low RPM's, in my case with the G56, in 6th. There is no power when you climb, even a small incline unless you down shift, then your RPM's are too high. :{

What do you consider "too high"? My '04. 5 had 4. 10's and I'd run 55-60mph in 5th all the time. Granted I tow absurdly heavy, but even on modest loads I couldn't stand being in OD at that speed unless on the flat. I had slightly taller than factory tires so I was running 2500rpm @ 60mph. Even that high, the mileage didn't suffer and the truck handled it a lot better.

 

[RVTRKN]

Stress on the rear end, no. But the 6spd AUTO has 2 overdrives, so even towing in 5th you're still in OD. Better than towing in 6th, but not as good stress-wise as towing in direct.







What do you consider "too high"? My '04. 5 had 4. 10's and I'd run 55-60mph in 5th all the time. Granted I tow absurdly heavy, but even on modest loads I couldn't stand being in OD at that speed unless on the flat. I had slightly taller than factory tires so I was running 2500rpm @ 60mph. Even that high, the mileage didn't suffer and the truck handled it a lot better.

It takes more torque to push a taller rear gear ratio, no matter what RPM you run at, in other words it is easier to turn a 4:10 than to turn a 3:73. The fact that your RPM's with the 4:10 are set at what you prefer to run, are just that, it is your prefered RPM. Kinda like always running up hill when you use a taller gear even though your on the same flat surface. Thats why the GCVWR can be different with the choice in rear ratio's.

 

[Cattletrkr]

It takes more torque to push a taller rear gear ratio, no matter what RPM you run at, in other words it is easier to turn a 4:10 than to turn a 3:73. The fact that your RPM's with the 4:10 are set at what you prefer to run, are just that, it is your prefered RPM. Kinda like always running up hill when you use a taller gear even though your on the same flat surface. Thats why the GCVWR can be different with the choice in rear ratio's.

I won't disagree with anything you said there. The point I'm trying to make is that with 4. 10's and a manual transmission, you virtually have to run in OD at freeway speeds. Uphill, downhill no difference. 4. 10's are the stronger rear ends, but they're not really made for freeways. All this talk about stress on the rear end and nobody is talking about blowing up the transmission.

3. 73's force you to downshift into 5th more often, which is a good thing.

 

[DPKetchum]

It stresses everything. Not just the rear axle.

 

[Forrest Nearing]

do the 3. 42's and enjoy!

 

[RVTRKN]

It stresses everything. Not just the rear axle.

That is a very true statement.

I won't disagree with anything you said there. The point I'm trying to make is that with 4. 10's and a manual transmission, you virtually have to run in OD at freeway speeds. Uphill, downhill no difference. 4. 10's are the stronger rear ends, but they're not really made for freeways. All this talk about stress on the rear end and nobody is talking about blowing up the transmission.



3. 73's force you to downshift into 5th more often, which is a good thing.

I agree with you, and if I had to do it all over again I would still pick the 3:73, but at 55 MPH its the pits and no matter were you are in CA its 55 MPH for Auto W/trailer & trucks :{:{:{

 

[Mhannink]

ok so here is my experience. now i am not an otr driver but i do know how to drive and tow ive been around trucks and hauled many a load. me i would go with the taller gears since it lets you downshift into the stronger gears in the trans and you can still pull at a decent speed. now my truck has 4. 10 which i hate(anyone with 3. 55s trade or sale) i was pulling a 14k lb toy hauler. we took it down to pismo for a weekend. most kalifornians know of pismo and most also know the grade coming out headed north. my guess is it is between 6 and 10 percent. it is steeper then the grape vine but not as long. my truck pulled the hill at 55 with a little throttle(read lots more power) just to maintain speed. this was in 5th. now if i had 3. 55s i would have been able to drop to 4th which is stronger then o. d. and pulled it and a better rpm at a little higher speed. so if you ask me go with the higher gears and be happy with it

 

[DPKetchum]

Besides towing at speed you have to get the weigh moving. I can't tell you how many 3. 55 gear sets the shop I worked in changed out for RV'ers and we threw in the trash for 4. 10s. I've owned two that I bought used(trucks)and tried the 3. 55s and hated the way they pulled with any weight. Even with modded engines. There IS a REASON that 4. 10s are a OPTION. I like the way my truck pulls. Not real thrilled about not towing but I didn't buy it for everday transportation. 99% of the time its on the road its hooked to something. The 09 1500s with a 10k plus tow rating have 3. 92 with new six speed autos(all but Dodge/5 speed auto) not 3. 54s or such. Hey I'm out of this discussion. You want to gut your truck starting off and pulling hills and downshifting to maintain speed go with a tall gear. Not me. Been there done that.

 

[tempforce]

i'm running the 3. 73's in my '08' mega. with a 6 speed auto, towing a car hauler or my r. v. both around 10-11,000 lbs. plus the back of the truck loaded. i drop at least one gear going up or down the hills, in oregon. sometimes i drop to 4th/direct. if i need to get slow ie 55 mph.

one time i used 3rd going up the pass near bakersfield, ca. as i didn't get up to speed prior to hitting the hill. (i slow down when i'm in fog). the next trip, i made sure i was at 50 mph before hitting the grade.

the 3. 73's are a good all around gear. i was wanting the 3. 42's but at the time i bought my truck they wern't available with a auto. i'm glad i have the 3. 73's.

 

[RVTRKN]

Besides towing at speed you have to get the weigh moving. I can't tell you how many 3. 55 gear sets the shop I worked in changed out for RV'ers and we threw in the trash for 4. 10s. I've owned two that I bought used(trucks)and tried the 3. 55s and hated the way they pulled with any weight. Even with modded engines. There IS a REASON that 4. 10s are a OPTION. I like the way my truck pulls. Not real thrilled about not towing but I didn't buy it for everday transportation. 99% of the time its on the road its hooked to something. The 09 1500s with a 10k plus tow rating have 3. 92 with new six speed autos(all but Dodge/5 speed auto) not 3. 54s or such. Hey I'm out of this discussion. You want to gut your truck starting off and pulling hills and downshifting to maintain speed go with a tall gear. Not me. Been there done that.

That is the reason I chose the 3:73, because it is a good compromise between to tall and to low for my driving habits and truck use. The best would be 4:10, but I just couldn't go with it due to 60% city driving. What I realy wanted were the Dana's Dodge used to have but you can't have everything.

 

[FFeiller]

i don't suppose you have a chance at trying each with a load to see how it feels.

in SF Bay my 05 with 3. 73 gears and auto couldn't handle a 14,000lb trailer on steep grades. but then there is a big difference between the auto and stick. that's why i ended up with a 5500 and 4. 88 with auto, it purrs up the grades.

 

[tempforce]

towing and mileage

i forgot to give my mileage figures with my above post, as that may make a difference.

loaded i average 10-12 mpg

empty i average 18-24 mpg

using hand calculator

remember i have a 2 wheel drive with stock tires.

 

[WCorbett]

Since your choice with the G56 is only 3. 73 or 3. 42, I'd go with the 3. 73, and then if you decide its too low you can adjust downward (taller) with tire size changes. If I remember my calcs correctly, the 3. 73 (with the factory 265/70/17) becomes about 3. 60 with the 285/70/17, and about 3. 52 with the 285/75/17. I run the latter, and it tows great, and 5th gear runs at about 2000 rpm at ~60 - 65 mph.



2 pennies... ... ... .

 

[NStates]

It depends on the definition of heavy hauling. I have been pulling heavy fifth wheels for 11 years and four trucks in that time. On previous trucks I added the Banks or Edge systems. I do not find it necessary on my 08. I run open road and always flow with the traffic. Running 3. 73 works very well with my Mobile Suite 17,000 # fifth wheel. No problem running the steepest of the western mountains. The 08 is one of the finest I have owned.



ROVOL



2008 Dodge RAM 3500 Laramie Quad Cab 4X2



6. 7 Liter Cummins (R) Turbo Diesel Engine, 6 -Speed Automatic 68RFE Transmission, 3. 73 Anti-Spin Differential, Brilliant White, ISSPRO Gauges, Transfer Flow Fuel Tank, PullRite #20,500 Super 5th Hitch, Line-X, XTRA Bed liner , Hayes Genesis brake controller, PML Deep Transmission Pan, Custom Graphics, Pull a Mobile Suites Fifth Wheel.

 

[HBarlow]

Are you on drugs????? I'm not trying to offend anyone, but you can get a Kenworth T660 with 3. 36s, you can get a Freightshaker Cascadia with 3. 42s, a Pete 379 with 3. 25s, and I know you can get Volvos in the 3. 42, maybe lower. These are heavy haul highway trucks. The 6. 7 has a very large power band and the new G56 does a great job of making the most of it. A bit of driving skill doesn't hurt either

Yep, you are correct. But KWs, Fls, Petes, and Volvos have 10 speed or even, in some cases, 18 speed transmissions. They also don't have the weak dual mass flywheel/clutch assemblies that Dodge Rams have had since 2006.