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Discussion Starter #1
So question for those out there who have driven both with larger than stock tires:

How do you feel the new 10 speed with the higher rear ratio compares to the 6 speed with the lower rear ratio?

It just seems so odd to me that GM went with 3.42 gears no matter what, but Ford offers anything from a 3.31 up to a 4.30, with a 10 speed that is actually geared lower than the GM 10 speed
 

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So question for those out there who have driven both with larger than stock tires:

How do you feel the new 10 speed with the higher rear ratio compares to the 6 speed with the lower rear ratio?

It just seems so odd to me that GM went with 3.42 gears no matter what, but Ford offers anything from a 3.31 up to a 4.30, with a 10 speed that is actually geared lower than the GM 10 speed
I agree ... it is sad that GM does not offer more ring and pinion gear options.
 

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Discussion Starter #4
I agree ... it is sad that GM does not offer more ring and pinion gear options.
Only thing I can think of other than mileage is to have something easy to upgrade the next time they bump tow weights.

It isn't a new axle is it? It's one they've used for a while so the parts already exist.

Want to jump over Ford with their 37k lb limit? Oh hey, we now have 4.10s that allow us to be higher!

Not saying they wouldn't up engine power but offering gears you previously carried would obviously be very easy to do
 

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Only thing I can think of other than mileage is to have something easy to upgrade the next time they bump tow weights.

It isn't a new axle is it? It's one they've used for a while so the parts already exist.

Want to jump over Ford with their 37k lb limit? Oh hey, we now have 4.10s that allow us to be higher!

Not saying they wouldn't up engine power but offering gears you previously carried would obviously be very easy to do
I heard the 2500 is an 11.5 inch ring gear and the 3500 is a 12 inch. If it is true, that would mean they changed from 2019 to 2020 on the 3500’s.
 

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Discussion Starter #6
I heard the 2500 is an 11.5 inch ring gear and the 3500 is a 12 inch. If it is true, that would mean they changed from 2019 to 2020 on the 3500’s.
Why was I thinking I had read that GM and Ram used the same 12 inch rear, therefore it was really common?
 

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Why was I thinking I had read that GM and Ram used the same 12 inch rear, therefore it was really common?
“GM's engineers beefed up the size of the '20 HD's drivelines by 30 percent. While the single-rear-wheel 2500/3500HDs retain the same American Axle & Manufacturing (AAM) 11.5-inch ring gear in the rear axlehousings and 14.1x1.3-inch disc brakes as '19, the 3500 dual-rear-wheel (DRW) models now run AAM's massive rear differential with a 12-inch ring gear, tree trunk-sized 4.25-inch axletubes, and 14x1.6-inch brake rotors front and rear.“

 

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Discussion Starter #8
“GM's engineers beefed up the size of the '20 HD's drivelines by 30 percent. While the single-rear-wheel 2500/3500HDs retain the same American Axle & Manufacturing (AAM) 11.5-inch ring gear in the rear axlehousings and 14.1x1.3-inch disc brakes as '19, the 3500 dual-rear-wheel (DRW) models now run AAM's massive rear differential with a 12-inch ring gear, tree trunk-sized 4.25-inch axletubes, and 14x1.6-inch brake rotors front and rear.“

So a quick Google search and it is the same 12 inch rear as the Rams, which come with 3.73 or 4.10

Come on GM!
 

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The article is incorrect. 3500 srw runs 12 in as well. Ram needs higher gear ratios to offset their crappy trans on diesel side.

#iworkforGM
 

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Discussion Starter #10
The article is incorrect. 3500 srw runs 12 in as well. Ram needs higher gear ratios to offset their crappy trans on diesel side.

#iworkforGM
Different rear axle but then what is Fords reasoning?

Not only can their axles be had with lower gears, but their 10 speed has lower gearing overall compared to GM.
 

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Different rear axle but then what is Fords reasoning?

Not only can their axles be had with lower gears, but their 10 speed has lower gearing overall compared to GM.
Powerband / boost points and engine speed for cooling. There's a method to their madness. Be mindful that the GM/Ford 10 speed trans is the same unit now
 

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Discussion Starter #12
Powerband / boost points and engine speed for cooling. There's a method to their madness. Be mindful that the GM/Ford 10 speed trans is the same unit now
Even if they are the same trans, which I still read to this day that they are and they aren't, the ratios are different.

I honestly do think GM went with the higher axle gearing to be able to simply throw in some 4.10s next time to up the tow rating.

3.55s in the Ford gets you 32,400
4.10 gets you 35,750

Both regular cab 2wd simply for ease of comparison.

Jump to the 450 with 4.30s and then you get to the 37,000 number but that also gets you some other driveline changes so not sure it's a fair comparison
 

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Powerband / boost points and engine speed for cooling. There's a method to their madness. Be mindful that the GM/Ford 10 speed trans is the same unit now
The GM/Ford 10 speed is in the 1/2 ton trucks, not in the HD.s
 

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Discussion Starter #15
can the 2020 2500s have 3.73 or 4.10s thrown in it?
No, there are no optional gear ratios from the factory.

It's either 3.73 for gas, or 3.42 for diesel.

Doesn't matter if it's 2500, 3500, SRW, DRW regular cab, extended cab, crew cab, etc.
 

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Might want to remember that GM just reintroduced their 4500, 5500 & 6500 commercial trucks again. Therefore GM’s stance will probably be that if you need the lower gear ratio in the HD platform then you probably should move up to the commercial platform with a larger chassis.

Not saying I agree, because I could really use 4:10’s, or even better 4:56’s, in my 2019 SRW 3500 to turn those 35 inch tires like it did those dinky 32 inch tires from the factory. But I can’t even change my ring and pinions without losing my cruise control thanks to GM locking down the ECM on the L5P. Ya I could spend $5k+ for an aftermarket ECM, but ain’t gonna do that for cruise control.

But back to the point.

GM likely also took into consideration that not enough other gear ratios are sold to justify making their supply chain any more complex than it already is. Part of that lean manufacturing crap.

Anyway, just a couple more theories why they only offer 3:42’s.
 

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Discussion Starter #17
Might want to remember that GM just reintroduced their 4500, 5500 & 6500 commercial trucks again. Therefore GM’s stance will probably be that if you need the lower gear ratio in the HD platform then you probably should move up to the commercial platform with a larger chassis.

Not saying I agree, because I could really use 4:10’s, or even better 4:56’s, in my 2019 SRW 3500 to turn those 35 inch tires like it did those dinky 32 inch tires from the factory. But I can’t even change my ring and pinions without losing my cruise control thanks to GM locking down the ECM on the L5P. Ya I could spend $5k+ for an aftermarket ECM, but ain’t gonna do that for cruise control.

But back to the point.

GM likely also took into consideration that not enough other gear ratios are sold to justify making their supply chain any more complex than it already is. Part of that lean manufacturing crap.

Anyway, just a couple more theories why they only offer 3:42’s.
Entirely plausible as well.

I'm honestly curious to see where all the manufacturers go.

GM and Ford just introduced the 10 speed, so that's not changing any time soon to help up tow ratings.

I could be wrong but I also wonder just how much further can they go with the engines in the current setup, and still meet reliability and emissions standards.

Will it be as simple as a gear swap for GM? Will all 3 introduce larger displacement engines in the next few years? Will tow ratings plateau?

I also wonder just how far do they push the trucks tow limits before somebody steps in and says no, that's too much for a vehicle this size.
 

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Entirely plausible as well.

I'm honestly curious to see where all the manufacturers go.

GM and Ford just introduced the 10 speed, so that's not changing any time soon to help up tow ratings.

I could be wrong but I also wonder just how much further can they go with the engines in the current setup, and still meet reliability and emissions standards.

Will it be as simple as a gear swap for GM? Will all 3 introduce larger displacement engines in the next few years? Will tow ratings plateau?

I also wonder just how far do they push the trucks tow limits before somebody steps in and says no, that's too much for a vehicle this size.
These trucks are already towing wayyyyy more than I currently need. No longer in the construction business hauling heavy equipment, so the most my truck sees any more is hauling our 12k RV. But never say never. I have been eyeing a Grand Design Momentum triple axle toy hauler for our 4-person UTV, but that would only be purchased if I upgraded to a dually.

 

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No, there are no optional gear ratios from the factory.

It's either 3.73 for gas, or 3.42 for diesel.

Doesn't matter if it's 2500, 3500, SRW, DRW regular cab, extended cab, crew cab, etc.
I understand that from the factory. I was talking about the aftermarket?? What affect would that have on the tranny, speedo, odometer, etc....
I regeared my Ram, and it had no affect on those other than the tranny seemed to shift better and the engine was no longer lugging in certain gears



Might want to remember that GM just reintroduced their 4500, 5500 & 6500 commercial trucks again. Therefore GM’s stance will probably be that if you need the lower gear ratio in the HD platform then you probably should move up to the commercial platform with a larger chassis.

Not saying I agree, because I could really use 4:10’s, or even better 4:56’s, in my 2019 SRW 3500 to turn those 35 inch tires like it did those dinky 32 inch tires from the factory. But I can’t even change my ring and pinions without losing my cruise control thanks to GM locking down the ECM on the L5P. Ya I could spend $5k+ for an aftermarket ECM, but ain’t gonna do that for cruise control.

But back to the point.

GM likely also took into consideration that not enough other gear ratios are sold to justify making their supply chain any more complex than it already is. Part of that lean manufacturing crap.

Anyway, just a couple more theories why they only offer 3:42’s.

how does changing a ring and pinion make the truck loose cruise control??
 

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how does changing a ring and pinion make the truck loose cruise control??
Its my understanding, and i could be wrong here, the cruise control uses some type of algorithm between engine speed and wheel speed. When it needs to increase vehicle speed it increases engine speed (or downshift etc) By changing the gear ratios, your wheel speed sensors do not match the parameters for the engine speed sensors. Instead of making you accelerate to 110 or decelerate to 27, it just becomes a fault in the system and that's that. I'm sure it can be tuned out tho

If you think thats crazy, on my NBS gasser I lost cruise control on a random Tuesday but nothing else. Turns out by putting an LED bulb in the driver side taillight, it messed with resistance somewhere down the line and it no longer worked. This was a common issue, im not joking lol.
 
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