Paddy
Adventurer
Well, a diesel can grunt through improper gearing I suppose. But yeah, with 35" tires and any load doing any kind of real truck work I'd say they probably wouldn't operate best with 3.73.
3.73 vs 4.10 in a 3/4 ton
- Thread starter live2travel photography
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Well, a diesel can grunt through improper gearing I suppose. But yeah, with 35" tires and any load doing any kind of real truck work I'd say they probably wouldn't operate best with 3.73.
Kaisen
Explorer
It all depends on the speeds you're trying to do that work, now doesn't it?
My 2007 LBZ Duramax, for instance, makes 650 lb-ft at 1,600 rpm. I like to run 75 mph, and have 33" tires (32.8" actually). In 6th gear (0.62) I'm turning 1750 rpm at 75 mph with the stock 3.73 gears. With 35" tires (that typically measure 34.5") I'd be 1,690 rpm. Perfect. So why the heck would I need 4.10s???
Your idea of a "real truck" is flawed
My 2007 LBZ Duramax, for instance, makes 650 lb-ft at 1,600 rpm. I like to run 75 mph, and have 33" tires (32.8" actually). In 6th gear (0.62) I'm turning 1750 rpm at 75 mph with the stock 3.73 gears. With 35" tires (that typically measure 34.5") I'd be 1,690 rpm. Perfect. So why the heck would I need 4.10s???
Your idea of a "real truck" is flawed
Regcabguy
Oil eater.
Yeah,I've got the equivalent of 4.10's with my G-56's 0.79 final drive.
They work well with 35's. i wouldn't want higher gears with the camper load.
Regcabguy
Oil eater.
Same with most new Superduty trucks.
Id say "real trucks" have no trouble with tall gears, unlike the older trucks that suffered with them.
Anymore, a higher output motor, better transmission (more gears), and taller axle gears are the way to go.
Power when you need it, and the tall gears to allow the motor to operate at lower RPMs on the highway for better MPG.
How about 35's without a lift or leveling kit.
6.2 gasser and 6-speed auto, it has more than enough power for these tires, even with the 3:73s
I've ridden in a 2012 F-250 6.2. Crewcab,shortbed,4wd,315's with Carli suspension,external contractors rack and RTT tent.
Decent power,excellent ride but the dash read 8 mpg. I don't know what rear axle ratio it had. It was not over-reving at freeway speeds so I have to assume they were 3.73's.
I don't think heavy towing or carrying a cabover around is the 6.2's mission in life.
IdaSHO
IDACAMPER
Dash MPG gauge isnt exactly accurate, and even worse if you dont have the speedo re-calibrated for the larger rubber.
And the low RPMs at highway speeds is just as much to do witht he trans as the gears. The 6-speed is considered to be a 4-speed with two overdrives.
Again, good power, tall gears, decent fuel MPG. That's the recipe.
In daily driver status currently, as the truck is slowly prepped for 100% camper hauling duties, I'm seeing 14+MPG
That's with the 35's, and hand calc'd. My MPG gauge also reads WAY low (8-10MPG), due to the tires.
Your opinion about the motor and hard use is certainly your opinion. But the 6.2 has already proven to be a more than adequate power plant for towing and hauling heavy.
Its a serious work horse, with power to spare. Biggest difference between it and its 6.7 diesel counterpart (besides torque
) is that it likes RPMs when working.
No different than the 6.8 V10 is replaced. Both like to rev.
And the low RPMs at highway speeds is just as much to do witht he trans as the gears. The 6-speed is considered to be a 4-speed with two overdrives.
Again, good power, tall gears, decent fuel MPG. That's the recipe.
In daily driver status currently, as the truck is slowly prepped for 100% camper hauling duties, I'm seeing 14+MPG
That's with the 35's, and hand calc'd. My MPG gauge also reads WAY low (8-10MPG), due to the tires.
Your opinion about the motor and hard use is certainly your opinion. But the 6.2 has already proven to be a more than adequate power plant for towing and hauling heavy.
Its a serious work horse, with power to spare. Biggest difference between it and its 6.7 diesel counterpart (besides torque
) is that it likes RPMs when working.No different than the 6.8 V10 is replaced. Both like to rev.
IdaSHO
IDACAMPER
Also, to add to the mix...
Current camper hauler that we are soon to replace is a 1996 Powerstroke
Stock, chipped, and 3:55s, we continue to average 14-15 MPG.
Thats with the camper loaded, running 65-70 on the highway.
Without the camper the truck turns 18-20MPG
Again, tall gears make it happen.
Prior to the gear swap, it had the 4:10s, and it rarely saw better than 15MPG empty.
Current camper hauler that we are soon to replace is a 1996 Powerstroke
Stock, chipped, and 3:55s, we continue to average 14-15 MPG.
Thats with the camper loaded, running 65-70 on the highway.
Without the camper the truck turns 18-20MPG
Again, tall gears make it happen.
Prior to the gear swap, it had the 4:10s, and it rarely saw better than 15MPG empty.
Mickey Bitsko
Adventurer
I had 355's in a f250 went down one size tire and picked up a little torque.
Just saying..
Just saying..
IdaSHO
IDACAMPER
For sure.
Most people would, especially if towing regularly.
But for a rig that does little towing, I say go with the tall gears, or at least run the gears you have for a while, before committing to an expensive gear swap.
Running tall gears, it doesn't hurt to drop a gear or two to pull that grade.
That's what those gears in the trans are for
Personally, I feel the 3:55s in a chipped 7.3, on stock size rubber is the perfect combo.
If I were towing regularly, or running big rubber, or especially both, Id certainly go for lower gears.
Most people would, especially if towing regularly.
But for a rig that does little towing, I say go with the tall gears, or at least run the gears you have for a while, before committing to an expensive gear swap.
Running tall gears, it doesn't hurt to drop a gear or two to pull that grade.
That's what those gears in the trans are for
Personally, I feel the 3:55s in a chipped 7.3, on stock size rubber is the perfect combo.
If I were towing regularly, or running big rubber, or especially both, Id certainly go for lower gears.
Ducky's Dad
Explorer
If you run the numbers, you generally won't save enough on fuel to offset the cost of the gear swap to longer gears on a 4WD truck. With rare exceptions, it only makes economic sense if you are going to keep the truck for a long time and a lot of miles. My Power Wagon came with 4.56s and after checking the cost of a change to 4.10s, I decided to live with the 4.56s. My Tundra came with 4.30s and they are just wrong for that truck, but the cost of the swap makes no sense.
IdaSHO
IDACAMPER
Depends on how you do it.
My regear, and solid axle sap, for that matter, didnt cost me anything but time.
Scored the right truck with the right gears and axles, for the right price.
Swapped everything over, then parted out the rest of the truck.
If I remember correctly, I think I actually made money on the deal.
On the other hand, most people wont be doing this. And as you mentioned, a regear is hard to justify if you actually run the numbers.
And that's why I say you should rather error on the side of too tall of gear, vs too low.
Too low a gear and you will hate highway travel.
Too tall a gear, never a real worry unless towing heavy. Even then, all you need to do is downshift.
My regear, and solid axle sap, for that matter, didnt cost me anything but time.
Scored the right truck with the right gears and axles, for the right price.
Swapped everything over, then parted out the rest of the truck.
If I remember correctly, I think I actually made money on the deal.
On the other hand, most people wont be doing this. And as you mentioned, a regear is hard to justify if you actually run the numbers.
And that's why I say you should rather error on the side of too tall of gear, vs too low.
Too low a gear and you will hate highway travel.
Too tall a gear, never a real worry unless towing heavy. Even then, all you need to do is downshift.
Yup, this. ^^^^^^^^^^^^^^^^^^^^^^^
We had a 2004 Dodge Ram 2500 w/4.10s & auto trans & it absolutely sucked for towing our 10,500 lb Toy Hauler. Great truck but the transmissions gear ratios were all wrong for HD work. I installed a 1 ton 24 row trans cooler & a 21"x12"x1.5" engine oil cooler, just to keep it from self destructing while towing the Toy Hauler for the 4 years we had that truck. It would shift from 2nd to 3rd, then drop back down to 2nd & repeat, 4x in 60 seconds, on flat ground, into the wind, just to maintain 55 mph. Had the trans reflashed. It still sucked. Traded it on the Power Wagon.
We have a 2008 Dodge Power Wagon w/4.56's & the G-56 manual trans. Stock suspension, stock 33" tall tires. It is a towing BEAST. I LOVE it for that reason. I towed a 10,500 lb Toy Hauler for 8 years with it. The manual trans gearing & the 4.56's made ALL the difference. It towed that same Toy Hauler like nobody's business. We have since traded it in on a 3500 lb single axle 18' camper. The PW does not even know it is back there. I usually tow at 60 mph now, even if the speed limit is 65 or 70. I have found that 70-80 mph raises the temp in the rear diff to uncomfortable levels. At least in my truck. Even with Amsoil. I have not tried their Severe Gear yet though, it will be going in next oil change. At 60 mph, when towing the 3500 lb camper, the rear diff temp is usually between 170*F & 177*F.
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Comanche Scott
Expedition Leader
Data mining for gearing efficiency
There is a great website for analyzing gearing effects.
http://www.grimmjeeper.com/gears.html
Using this chart, and then looking at the torque/HP curves, and efficiency curve of the engine, will provide some great insight into good choices based on driving conditions/applications.
I did this on my last two builds (a pro-touring Mustang, and a 4BT conversion in an old Scout). I was really happy with the results.
Lastly, and I don't fully understand this but... Certain rear ends are more efficient with certain gear sets. There is more than just pinion position in the housing that changes this.
Every differential has a sweet spot in regards to gearing, which relates to how the pinion and ring gears mesh, and the amount of loading the gears see. This translates to efficiency.
I've seen this over the years with different rearend rebuilds on commercial vehicles, and even some custom builds. I've never quantified the feedback, but keyed into this from an article in a trade magazine back in the early days of the Ford 8.8.
Any way, I don't claim to be an expert by any means, but have had the good fortune to be involved with a lot of builds, and that has definitely been a huge help to pick good combinations.
Hope this insight is helpful to you. :beer:
There is a great website for analyzing gearing effects.
http://www.grimmjeeper.com/gears.html
Using this chart, and then looking at the torque/HP curves, and efficiency curve of the engine, will provide some great insight into good choices based on driving conditions/applications.
I did this on my last two builds (a pro-touring Mustang, and a 4BT conversion in an old Scout). I was really happy with the results.
Lastly, and I don't fully understand this but... Certain rear ends are more efficient with certain gear sets. There is more than just pinion position in the housing that changes this.
Every differential has a sweet spot in regards to gearing, which relates to how the pinion and ring gears mesh, and the amount of loading the gears see. This translates to efficiency.
I've seen this over the years with different rearend rebuilds on commercial vehicles, and even some custom builds. I've never quantified the feedback, but keyed into this from an article in a trade magazine back in the early days of the Ford 8.8.
Any way, I don't claim to be an expert by any means, but have had the good fortune to be involved with a lot of builds, and that has definitely been a huge help to pick good combinations.
Hope this insight is helpful to you. :beer:
pappawheely
Autonomous4X4
I like the 4:10's on my F350. I switched to 37 inch tires that cause me to downshift out of overdrive (5 speed manual) on the steeper hills, but the payoff is being able to hypermile on the fwy. Most of the time, I only need the increased torque when I am offroad. 4x4 takes care of that.
live2travel photography
Adventurer
There is a great website for analyzing gearing effects.
http://www.grimmjeeper.com/gears.html
Using this chart, and then looking at the torque/HP curves, and efficiency curve of the engine, will provide some great insight into good choices based on driving conditions/applications.
I did this on my last two builds (a pro-touring Mustang, and a 4BT conversion in an old Scout). I was really happy with the results.
Lastly, and I don't fully understand this but... Certain rear ends are more efficient with certain gear sets. There is more than just pinion position in the housing that changes this.
Every differential has a sweet spot in regards to gearing, which relates to how the pinion and ring gears mesh, and the amount of loading the gears see. This translates to efficiency.
I've seen this over the years with different rearend rebuilds on commercial vehicles, and even some custom builds. I've never quantified the feedback, but keyed into this from an article in a trade magazine back in the early days of the Ford 8.8.
Any way, I don't claim to be an expert by any means, but have had the good fortune to be involved with a lot of builds, and that has definitely been a huge help to pick good combinations.
Hope this insight is helpful to you. :beer:
Awesome link! Thanks