2016 Sierra 6.2 8speed aftermarket 4.10 gears?

07Softail · January 27, 2016

3.73's are perfect and all trucks should come with that ratio standard.

RT

WhiteLMM · January 27, 2016

Txmuder. Awesome input thank you! What tire size are you running? And would you say the gear swap was worth it?

chevydeth · July 22, 2016

Anyone have a link to purchase 3.73's online? I'm not sure exactly what to get. 2016 6.2L 8 spd here with stock 3.23's. Also would any other mods need to be done (Example tuning?)

Cliff14Denali · July 22, 2016

I am interested too but I have a 2014 with 6.2L and for the longest time no one made anything for the larger rears in the 6.2L trucks. I found this the other day....

http://www.demandaam.com/axle-results?vm=GM&q=9.76%22+12+Bolt+-+Rear+Axle

Once you do the gear swap a simple tune should work with everything else.

Badass69 · July 22, 2016

Be nice if we could get aftermarket carriers so one could ditch the Gov Junk...

Sent from my SM-G900W8 using Tapatalk

BBChevy2017 · April 7, 2020

On 1/25/2016 at 7:15 AM, WhiteLMM said:

Hey guys. Like the topic says Ive got a 2016 Sierra 6.2 and 8speed auto. Im modding the truck for a buddy. I installed a 5" rough country lift and 20x10 wheels and 305/55r20 tires. Actual diameter is 33.5" I'm wondering if 4.10 gears would be beneficial for performance or if it would just be too much quick shifting? I used a ratio calculator and with the 33s and 4.10 gears the trucks would be spinning 300rpm more at 60mph than when the truck was 100% stock.

WhiteLMM,

what gears did your friend end up going with on this lifted 6.2 liter Chevy?

I have been researching online regarding re-gearing and ran across your post.

I just bought a 2017 Silverado 1/2 ton crew cab standard bed Z71 with the 6.2 liter motor, 8 speed transmission and 3.23 gear ratio.

I am going to lift my truck and having a hard time debating between a 4” or 6” BDS. I love the look of 6”, but afraid with my high factory gears, it would require re-gearing. If I go with a 4”, I will run 275/70/18 (33.6”) and if I get a 6” I would go 285/70/18 (34.1”) or 295/70/18 (34.5”). The tire I will be going with is Toyo Open Country has MY. My factory stock tire is 275/55/20 which is (31.9”).

Currently with my stock setup, I love the power and gas mileage. Just too short now. Need my lift on.

Most shops I talk to say to re-gear, but I don’t want to do lower gears and regret it with my truck sucking gas. So far people are saying 3.73 for the 33” tires and 4.30 for 34”/35” tires.

Look forward to hearing back from you.

CamGTP · April 7, 2020

The 8 speed transmission changes things compared to the older 4 speeds and 6 speeds.

33's would do good with 4.10's and 35's with 4.56's on the older 4 speeds.

33's would do pretty good with 3.73's in a 6 speed and 35's with 4.10's.

I'd do 3.73's at the minimum with 33's or 34's in a 8 speed. Remember that the advertised height of the tire will be a little less in real life and with weight on the wheels. 34.1in probably loses a half inch.

The 8L90e has a final gear ratio of .65, so plug that into a calculator and you get these results.

33's with 3.23's at 70mph is 1,500rpm.

33's with 3.73's at 70mph is 1,700rpm.

34's with 3.73's at 70mph is 1,670rpm.

Add 200rpm to 3.73's results if you went with 4.10's.

It'll be up to you if you think you need new gears. To gain back all mechanical advantage a gear change would be required. I'd say the vast majority don't spend the money and keep it as is. The 6.2 at least puts down more than power the 5.3, so that is very helpful.

Edited April 7, 2020 by CamGTP

truckguy82 · April 7, 2020

On 1/25/2016 at 12:16 PM, WhiteLMM said:

Unless it is the max trailer packege with 3.42 gears all other 6.2 are 3.23

2014 6.2 had 3.73 max trailer since it had a 6l80 trans. I have a non max tow 6.2 3.42.

to answer your question, the more gears your trans has and the faster it shifts, the less relevant diff gears are.

you def do not need gears and it would be a complete waste of money

Edited April 7, 2020 by truckguy82

truckguy82 · April 7, 2020

8 hours ago, CamGTP said:

The 8 speed transmission changes things compared to the older 4 speeds and 6 speeds.

33's would do good with 4.10's and 35's with 4.56's on the older 4 speeds.

33's would do pretty good with 3.73's in a 6 speed and 35's with 4.10's.

I'd do 3.73's at the minimum with 33's or 34's in a 8 speed. Remember that the advertised height of the tire will be a little less in real life and with weight on the wheels. 34.1in probably loses a half inch.

The 8L90e has a final gear ratio of .65, so plug that into a calculator and you get these results.

33's with 3.23's at 70mph is 1,500rpm.

33's with 3.73's at 70mph is 1,700rpm.

34's with 3.73's at 70mph is 1,670rpm.

Add 200rpm to 3.73's results if you went with 4.10's.

It'll be up to you if you think you need new gears. To gain back all mechanical advantage a gear change would be required. I'd say the vast majority don't spend the money and keep it as is. The 6.2 at least puts down more than power the 5.3, so that is very helpful.

The thing is, there is really not much mechanical advantage at all.

when you increase gear ratio, you are shortening the amount of time in each gear

so what has more mechanical advantage.....(hypothetical numbers)

4.10’s, with 1st gear going up to 0-20mph

or

3.23 with first gear going up to 30mph

with the 4.10’s yes 0-20mph might have more mechanical advantage, but what about 20-30mph, where your 4.10 car is in 2nd gear and your 3.23 car is still in 1st gear?

IMO the only thing gears helps with is if you have too much traction in first gear and you don’t have the power to spin them. A 6.2 has that power unless you have I’m guessing 35” or bigger tire. And even then, it will not help that much.

if you can spin 1st gear, you don’t need gears

(save for super off road rigs, totally different)

jrabenaldt · April 7, 2020

My '16 w/ 6/2 and 3.43's will spin my 35" Ridge Grapplers w/o thinking twice. My simple opinion based solely on my own experience with my own truck; unless your pulling a huge amount of weight or chasing Jeeps crawling up rock faces the gearing in these is just fine.

Just my thought, worth what was paid....

Jetiemann · April 7, 2020

Anyone else curious about what a 5" lift on 33" tires is going to look like?

AdioSS · April 7, 2020

I say go for the 4.10s! I put those in my 96 Impala SS with 28” tires. I originally put in 3.73s with the factory posi, but the posi blew up around The 100k mile mark. I drove the car another 65k miles with the deeper gears.

BBChevy2017 · April 8, 2020

Thank you everyone for your help on the questions I had.

ToddG59 · April 3, 2021

Good Afternoon

I have been reading the past post on gear options, I have a 2015 Denali supercharged that delivers 540ft lbs of torque to the ground at 4800 RPM,. The Denali has the 3.23 differential gears am considering 3.73 gears with a truetrac limited slip for towing enclosed car trailer with a Chevelle convertible. Watch a couple videos with a stock Denali towing a 7500LB load the truck was running about 4200 rpms going through the Eisenhower tunnel. Has anyone done any motor modifications to a 6.2 with 8L90 trans.

lucas287 · April 8, 2021

On 4/3/2021 at 4:46 PM, ToddG59 said:

Good Afternoon

I have been reading the past post on gear options, I have a 2015 Denali supercharged that delivers 540ft lbs of torque to the ground at 4800 RPM,. The Denali has the 3.23 differential gears am considering 3.73 gears with a truetrac limited slip for towing enclosed car trailer with a Chevelle convertible. Watch a couple videos with a stock Denali towing a 7500LB load the truck was running about 4200 rpms going through the Eisenhower tunnel. Has anyone done any motor modifications to a 6.2 with 8L90 trans.

You're telling me that a blown L86 doesn't have enough torque to pull that trailer with 3.23? I've pulled ~5k many times and I've never struggled and I'm not blown. Sure, maybe not in 8th but that's the beauty of having 8 gears. Drive in 6th or 7th!

If it were my money, I'd do the following. Buy HPTuners and modify the tow/haul map to lock out 7th or 8th. And then upgrade to LT4 injectors and fuel pump and convert to e85. After a good tune you'll easily pick up 40-50 lb ft down low.