PyroJoe
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I'm creating this thread so we can stay updated on the ring and pinion offerings for 2025+ Cummins trucks.
As of Jan 2026, we are still stuck with only 3.42 as a factory option. The guys with the AAM 1150 have it a lot better because that axle's been around for over 25 years with tons of aftermarket support.
Us dually 12" AAM owners are up against a wall. There are 3.73 and 4.10 OEM options for them, but just the R&P costs $1100 alone. You still have to add the setup kit on top. And the front axle! And labor!
***Edit: Here are the most economical current R&P sets we've found:
3.73
4.10
****
I plan to regear my 2025 DRW Cummins to 3.73 for my 35's as soon as it's economically feasible. Right now, my gear shop has given me a quote of $4k.
I wish RAM would pull their heads out of their butts and give us more factory options. For a 19-24 truck, it was less than $200 to upgrade to 4.10's
I had already planned my whole truck build before I ordered and wanted the deeper gears for my 35's. But of course, they had to drop gear options in 2025...
And the other point I'd like to make is that with the announcement of the 2027 Cummins Power Wagon yesterday, we now know that the 5th gen is in fact not going to come for 2027
But, now that we know that even with a "big tire" Power Wagon off-road-purposed Cummins still only being offered with the pathetic 3.42's, I have to ask- Is there different transmission tuning for different trim levels and their different tire diameters? The Limited's has 33.5" tires vs the dually with 31.8" tires. Apparently the 2027 Power Wagon is getting the same height tire as the Limited and yet they're STILLLLLLL stuck with 3.42's!
For those new to the world of R&P ratios, here is why it is important. I recently changed my 2025 Cummins DRW from the stock 31.8" to a 34.6" tire, and the difference is just as horrifying as I imagined. Significant loss of power and braking. And now it downshifts like crazy. I drove it stock from Nebraska to Vegas thru the MOUNTAINS on a 107°F day at 80-85mph with my 4k lb trailer and it would only drop from 8th to 7th if I was really stepping on it. Now in Nebraska 40°F outside with same trailer it drops out of 8th for every little hill. I had dealership recalibrate the gauge cluster for tire size, but they didn't mention any transmission tuning changes. It definitely operates better since getting the speedo recalibrated, but it still sucks compared to stock.
I can't imagine shelling out $80-100k for one of these 27 PW's to get the lack of performance my dually now has. They're absolutely shooting themselves in the foot with the lack of R&P options on these.
One last thought - they need to offer a driving mode that allows you to start in 1st gear when NOT in tow/haul mode. The only way to do this right now is to manually shift down into 1, then you have manually turn manual mode off. It is not feasible in the slightest sense. I wonder if the 27 PW will have this mode. With stock 31.8" tires, I never ever wanted 1st gear unless I was towing or creeping thru a traffic jam. With the 34.6" tires, I now prefer 1st gear for daily driving. The furds have all sorts of drive modes like sport/eco/towing/wet etc. I wish we could have something like that which would enable a 1st gear start-out.
As of Jan 2026, we are still stuck with only 3.42 as a factory option. The guys with the AAM 1150 have it a lot better because that axle's been around for over 25 years with tons of aftermarket support.
Us dually 12" AAM owners are up against a wall. There are 3.73 and 4.10 OEM options for them, but just the R&P costs $1100 alone. You still have to add the setup kit on top. And the front axle! And labor!
***Edit: Here are the most economical current R&P sets we've found:
3.73
4.10
****
I plan to regear my 2025 DRW Cummins to 3.73 for my 35's as soon as it's economically feasible. Right now, my gear shop has given me a quote of $4k.
I wish RAM would pull their heads out of their butts and give us more factory options. For a 19-24 truck, it was less than $200 to upgrade to 4.10's
I had already planned my whole truck build before I ordered and wanted the deeper gears for my 35's. But of course, they had to drop gear options in 2025...
And the other point I'd like to make is that with the announcement of the 2027 Cummins Power Wagon yesterday, we now know that the 5th gen is in fact not going to come for 2027
But, now that we know that even with a "big tire" Power Wagon off-road-purposed Cummins still only being offered with the pathetic 3.42's, I have to ask- Is there different transmission tuning for different trim levels and their different tire diameters? The Limited's has 33.5" tires vs the dually with 31.8" tires. Apparently the 2027 Power Wagon is getting the same height tire as the Limited and yet they're STILLLLLLL stuck with 3.42's!
For those new to the world of R&P ratios, here is why it is important. I recently changed my 2025 Cummins DRW from the stock 31.8" to a 34.6" tire, and the difference is just as horrifying as I imagined. Significant loss of power and braking. And now it downshifts like crazy. I drove it stock from Nebraska to Vegas thru the MOUNTAINS on a 107°F day at 80-85mph with my 4k lb trailer and it would only drop from 8th to 7th if I was really stepping on it. Now in Nebraska 40°F outside with same trailer it drops out of 8th for every little hill. I had dealership recalibrate the gauge cluster for tire size, but they didn't mention any transmission tuning changes. It definitely operates better since getting the speedo recalibrated, but it still sucks compared to stock.
I can't imagine shelling out $80-100k for one of these 27 PW's to get the lack of performance my dually now has. They're absolutely shooting themselves in the foot with the lack of R&P options on these.
One last thought - they need to offer a driving mode that allows you to start in 1st gear when NOT in tow/haul mode. The only way to do this right now is to manually shift down into 1, then you have manually turn manual mode off. It is not feasible in the slightest sense. I wonder if the 27 PW will have this mode. With stock 31.8" tires, I never ever wanted 1st gear unless I was towing or creeping thru a traffic jam. With the 34.6" tires, I now prefer 1st gear for daily driving. The furds have all sorts of drive modes like sport/eco/towing/wet etc. I wish we could have something like that which would enable a 1st gear start-out.
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