Going to 3:92’s on a 3.6L

[pacofortacos]

I agree!!!! They’ll do it as promised but won’t warranty the transmission if it’s a complete failure.

This would stop me in my tracks - the trans is $$$$$$.

To be honest, I have the hemi w/3.92's and would prefer the 3.55's.

 

[pacofortacos]

The 3.6 with 3.92 is a standard option on the 2018 Rebel 4X4 - there is a chance the computer might take the upgrade - it should be easy enough to try it first.

Sales code DMH

 

[1morepart]

Spoke to a man named Matt. According to him, the transmission does not need anything to accept new gears. Only time you need to calibrate is for a tire size change on these eight speeds to get your speedometer accurate. I may pull the trigger now.

 

[pacofortacos]

I am not sure how the rpm change will affect the trans programming.
Will the dealer still void the trans warranty?

Speedo is tire size determined.

 

[Marine Les]

The 3.6 with 3.92 is a standard option on the 2018 Rebel 4X4 - there is a chance the computer might take the upgrade - it should be easy enough to try it first.

Sales code DMH

I think its standard on the 4x2 also.

 

[1morepart]

I am not sure how the rpm change will affect the trans programming.
Will the dealer still void the trans warranty?

Speedo is tire size determined.

It needs to match the vin. 3.21/3.55 do on my model

 

[Quyonmob]

Following. Thinking about going to 3.92 on my 17 crew. Most of my commute is 55mph anyhow, would be nice to use 8th more often. Last time I towed a 4K travel trailer I was in 5th most of the time. Still got nearly 20mpg

 

[Statcher1]

This is really all you guys need if your 2wd. Along with a competent shop to do the install. There’s no need to worry about Trans Programming or any of that stuff that a dealer may throw at you.




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[Dusty]

I wouldn’t think it would need any trans reprogramming but your speedo may need to be recalibrated.

Best,
DG

Changing the ring and pinion in the rear differential will have no affect on the speedometer. The speedometer gets a signal from the Tone Ring and Speed Sensor in the differential, an independent part from the ring and pinion. The Tone Ring is the same for all axle ratios.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Now at: 008698 miles.

 

[1morepart]

Changing the ring and pinion in the rear differential will have no affect on the speedometer. The speedometer gets a signal from the Tone Ring and Speed Sensor in the differential, an independent part from the ring and pinion. The Tone Ring is the same for all axle ratios.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Now at: 008698 miles.

Nah, speedometer gets the signal from the abs at the wheels nothing to do with or in the pumpkin.

 

[1morepart]

Changing the ring and pinion in the rear differential will have no affect on the speedometer. The speedometer gets a signal from the Tone Ring and Speed Sensor in the differential, an independent part from the ring and pinion. The Tone Ring is the same for all axle ratios.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Now at: 008698 miles.

Nah, speedometer gets the signal fro the abs at the wheels nothing to do with or in the pumpkin.

 

[lharrell79]

Any updates?

 

[Random_Walk]

Can you go higher? Like 4:10”s? 3:21 to 3:92”s is a minimal change. I’m just curious is all. Hopefully it provides the improvements you are looking for.

3.21 to 3.92 would add a *lot* for the little 3.6 rig... Example? My '17 QuadCab: 3.21 gives you a max tow of 4430 or 4610 lbs (depending - 4x4 powertrain drops it to 4430 lbs). Swap it for 3.55, and suddenly max towing goes up to 7600 lbs (7420 for 4x4) on the same motor.

Towing charts don't even list what 3.92 will do for the little six-banger: https://www.ramtrucks.com/assets/towing_guide/pdf/2017_ram_1500_towing_charts.pdf

 

[Ratket]

What about the gears gives it more towing? It doesn’t change that door sticker, and I am being dead serious not being a smart ass.. I don’t understand how something you couldn’t tow with 321”s now you can with 392”s? Makes no sense to me. Sure the motor is going to work a little hard to get to what ever speed and maintain that speed. But to say it can’t because of such a minor incriminatal gear change just doesn’t make sense to me. Again not being a smart ass- I just don’t understand why. Someone take me to school please. Lol

 

[Random_Walk]

What about the gears gives it more towing?

Because physics

https://www.edmunds.com/car-buying/how-to-choose-the-right-axle-ratio-for-your-pickup-truck.html

Key quote:

Automakers build trucks with a range of optional axle ratios. The term refers to the gears in the truck's differential, which is a mechanical device that links the rear axle to the driveshaft and then the engine. Technically, the number should be expressed as a ratio, such as 3.55:1, meaning the drive shaft turns 3.55 times for each turn of a wheel. But that gear ratio would most commonly be referred to as "3.55" or simply "three fifty-five."

The key to understanding gear ratios is to remember that, as the numerical ratio goes up, towing capacity increases but fuel economy goes down. A numerically higher axle ratio provides a mechanical advantage to send more of the engine's available torque to the rear tires (and front tires, in a four-wheel drive vehicle), but you pay the price at the fuel pump.

 

[Marine Les]

Nah, speedometer gets the signal fro the abs at the wheels nothing to do with or in the pumpkin.

Calling 1morepart for an update on the gear change. Us 3.6 drivers are looking forward to hearing about the performance and mpg.

 

[likes2build]

$800 including new Mopar ring and pinion, new bearing kit, and all the labor.

@1morepart , was that price at a dealer or an independent?

Never mind, I see that your truck is gone now.................

 

[JPT]

Because physics

https://www.edmunds.com/car-buying/how-to-choose-the-right-axle-ratio-for-your-pickup-truck.html

Key quote:

I think the point he is making is, changing the setup to match the higher rated vehicles does not increase the towing limits of your actual vehicle. Unless there is some way to re-certify your truck, you are stuck towing to the door sticker limits.

You may be able to tow better, but if/when you get pulled over, you have gone over the limit of your actual vehicle.

 

[likes2build]

That's an interesting point, is there anyway to re-certify a vehicle to a higher limit after a gear change?

 

[JPT]

That's an interesting point, is there anyway to re-certify a vehicle to a higher limit after a gear change?

I'm going to guess you can't. I know commercially you can register at a LOWER towing limit to save registration fees, but I doubt you would be able to ever go higher than the door sticker.

With trailers it is different, you can modify your trailer and certify it higher, but vehicles are different.