Regear or buy another truck

[16LT4]

On 2/17/2023 at 1:00 PM, Homewrecker007 said:

I would definitely say get 3.73's or if you can get them for the front and rear go with 3.90's

 3.73s are what these trucks should have came with across the board anyway; the 5.3 likes/needs to rev, so the 3.73s would help motivating the truck, especially with any weight behind it.  Mine has 3.42s.  A few trucks ago I had a '14 Ram Laramie with the 5.7, 8 speed ZF, and 3.92s.  Between the added power of the engine over the 5.3 (and better torque curve), the perfect shifting of the ZF and the towing gearing, the truck was easily much more comfortable with the same weight trailer behind it, and got the same if not better fuel mileage than my '16 K2 while doing it.  Without a trailer, the Ram still achieved 22-23 mpg on the highway, despite more engine and more gears.  A 3.73 in the K2 would have a negligible effect, if any, on fuel consumption, and may actually improve around-town mileage due to keeping the engine in its power band.  I'd love to see data on that.  On a lifted truck with larger tires, definitly need to "gear it;" the larger tires effectively "ungeared it," and probably puts the truck in the 2.xx realm.

Edited February 22, 2023 by 16LT4

[Grumpy Bear]

On 2/17/2023 at 6:45 PM, mikeyk101 said:

Shouldn't 4WD have same gears on front and rear?

 Yes! 

 

Edited February 19, 2023 by Grumpy Bear

[Grumpy Bear]

40 minutes ago, 16LT4 said:

 3.73s are what these trucks should have came with across the board anyway; the 5.3 likes/needs to rev, so the 3.73s would help motivating the truck, especially with any weight behind it.  Mine has 3.42s.  A few trucks ago I had a '14 Ram Laramie with the 5.7, 8 speed ZF, and 3.92s.  Between the added power of the engine over the 5.3 (and better torque curve), the perfect shifting of the ZF and the towing gearing, the truck was easily much more comfortable with the same weight trailer behind it, and got the same if not better fuel mileage than my '16 K2 while doing it.  Without a trailer, the Ram still achieved 22-23 mpg on the highway, despite more engine and more gears.  A 3.73 in the K2 would have a negligible effect, if any, on fuel consumption, and may actually improve around-town mileage due to keeping the engine in its power band.  I'd love to see data on that.  On a lifted truck with larger tires, definitly need to "gear it;" the larger tires effectively "ungeared it," and probably puts the truck in the 2.xx realm.

 

If the truck in question has an 8 speed and 3.42's then running in 7th gear down the highway would be about the same as a 4.01 gear. 

 

If the truck has the 6 speed then like a 4.10

 

This won't tell you what it would be like accelerating but you could pin down the MPG difference. Pepper suffers about an 8% loss in milage running in M5 at 55 mph. 

[KARNUT]

I’m surprised with all the gears in the transmission that 373 gears in the rear wouldn’t be standard issue. Way back in my impala and nova days my first mod usually was a 273 to 373 swap. Before I had separate toys and my wife working when the kids were young. My wife drove our toys. The gear change would net about 2 miles per gallon in town. Where those vehicles spent most of their time. Even my trucks leaned 345-373 gears pulling or carrying tools and fuel tanks. Of course a like the acceleration and the crisp feel moving the mass. The later multi gear changes in the transmission while cruising seems counter productive.

[diyer2]

I believe my truck and many others come with 373 gears when the tow package is added. If that's true that gear is what GM thinks is better for overall performance IMO.

[mikeyk101]

I wish mine came with the 3.73 gears. I have the 6 speed and 3.42. mine came with the "Trailering Equipment Package" but seems like it only really added the auto locking rear differential. No trailer braking controller, I had to add an aftermarket one. I only tow my toy hauler a couple times a year and it comes in about 6200lbs loaded but go for a week or 2 at a time. The rest of the time, its my daily driver. It does ok when towing but the 3.73 gears would probably be a plus. I'm just not sure if it would be worth the cost to do. 

 

What would be a ball park figure if I had a place do it?

[Buckwild27]

My 2013 has the trailering package and it came with 3.42. I have changed both the 2010 and 2013 Sierra to 3.73's and Disc Brake bigger rear-end. will be doing 3.73 gear swap on the 2018 eventually. 

 

 

 

 

 

 

 

 

 

 

[16LT4]

On 2/19/2023 at 11:37 AM, mikeyk101 said:

I wish mine came with the 3.73 gears. I have the 6 speed and 3.42. mine came with the "Trailering Equipment Package" but seems like it only really added the auto locking rear differential. No trailer braking controller, I had to add an aftermarket one.

 My 4x4 '16, 5.3 with 6 speed, has G80 rear diff, factory trailer hitch and in-dash trailer brake controller.  It also has with 3.42s, so I guess it didn't have the "official" tow package that would have netted 3.73s.  Despite being an LT with factory center console and heated front seats, it also came with 17" wheels.  I'm not up on the various option packages, but it seems to be some interesting combination of basic and mid-upper level features.

Edited February 23, 2023 by 16LT4

[swathdiver]

On 2/19/2023 at 7:20 PM, Homewrecker007 said:

My 2013 has the trailering package and it came with 3.42. I have changed both the 2010 and 2013 Sierra to 3.73's and Disc Brake bigger rear-end. 

 

Would you mind sharing your experiences with the 3.73s on those two trucks?  

[Buckwild27]

14 hours ago, swathdiver said:

 

Would you mind sharing your experiences with the 3.73s on those two trucks?  

Best Decision I ever made. There is a slight mpg drop but not bad. Before the gear change, trucks were struggling to keep up with traffic pulling a trailer and constantly running at 5000 rpm. Swapped in the 3.73's now it will do 70-75 no problem 

[Buckwild27]

The lightest thing I pull is roughly 4000 combined weight of car and trailer is my 29 model A ford. The heaviest is my 2010 sierra crew cab short box in my enclosed trailer at a little under 10k combined weight. I did run 4.10 in my 06 that was a pulling beast Gas was less expensive in those days though so I never cared about mpg. My 91 gmc has F250 front and rear axles with 4.88 gears and 37's that thing will pull a house down roughly 300 miles of gas on front tank about 350 out of rear tank 

[swathdiver]

43 minutes ago, Homewrecker007 said:

Best Decision I ever made. There is a slight mpg drop but not bad. Before the gear change, trucks were struggling to keep up with traffic pulling a trailer and constantly running at 5000 rpm. Swapped in the 3.73's now it will do 70-75 no problem 

Thanks for confirming my suspicions!  In the midst of doing it with my Yukon XL which will include the larger 14-bolt axle. 

[Buckwild27]

1 hour ago, swathdiver said:

Thanks for confirming my suspicions!  In the midst of doing it with my Yukon XL which will include the larger 14-bolt axle. 

I really like the 14 bolt I put it in both trucks as well. I didn't change the master cylinder when I switched to Disc Brake in the rear but I think it would help to do so.

[swathdiver]

7 minutes ago, Homewrecker007 said:

I really like the 14 bolt I put it in both trucks as well. I didn't change the master cylinder when I switched to Disc Brake in the rear but I think it would help to do so.

 

Mine are all rear disc and the two Sierras have 6.2s, they came with the 14-bolt.  One has 3.42 gears and the other came with 3.73s as its an NHT.  It'll be nice to have all the drivetrains the same soon!

[Buckwild27]

5 minutes ago, swathdiver said:

 

Mine are all rear disc and the two Sierras have 6.2s, they came with the 14-bolt.  One has 3.42 gears and the other came with 3.73s as its an NHT.  It'll be nice to have all the drivetrains the same soon!

Nice. My 2010 (4.8l)and 2013 (5.3l) came with drum rears with the smaller rear-end and 3.42's the 2010 has an LSX376 B-15 in it now. No longer pull trailers with it. It will pass everything but a gas station.