Rear gear ratio change

[Chevy Silverado]

I have a 2011 Silverado 4X4 LS 4.8L  Model # CK10753 with a 3.42 rear gear ratio . I want to change to a 3.73 ratio . Does the front differential gear ratio also need to be changed ?

[CamGTP]

Yes, both must be changed.

 

Then the computer needs to be re-calibrated so the speedo works right and the transmission shifts properly again.

[Chevy Silverado]

What gear ratio is in front diff now , and what does it change to ?

What I`m looking for is a way to change towing capacity a bit by maybe a 1,000 lbs.

[CamGTP]

Trucks that are 4X4 must have matching front and rear gear ratio's.

 

So if the truck has 3.42's, then that is what is in the front and back.

 

Go deeper if you want awesome towing gears, like 4.10's. But the trade offs are worse fuel mileage because cruising speed rpm will be higher. 3.73's will be an improvement but remember you still have a underpowered 4.8 that can struggle with heavy loads.

[Brian715]

Our 4.8l work truck with 4.8l was a lot better with 4.10s. as everyone else has stated, both front and rear must match. I would find a donor truck and change the whole front diff and rear end instead of paying for a shop to setup new gears.  

[Chevy Silverado]

That does sound like a good idea, using a whole differential, and would be faster than setting up two sets of new gears.

But it does look like I need to update my truck and get a truck with a 5.3L .

Thank you for your reply .

[Grumpy Bear]

1 hour ago, Chevy Silverado said:

That does sound like a good idea, using a whole differential, and would be faster than setting up two sets of new gears.

But it does look like I need to update my truck and get a truck with a 5.3L .

Thank you for your reply .

Ah, you took the  bait and drank the Kool-Aid. 

 

[GM-Lifer]

That 4.8 has plenty of power. With the right gear ratio, I think you'd be surprised how well it pulls. Besides, it doesn't have that cylinder deactivate crap to worry about. Maybe I'm old school, but I still remember what you could get away with pulling with a 90 HP straight 6 cylinder in a pickup.

[Grumpy Bear]

On 8/14/2020 at 10:10 PM, GM-Lifer said:

That 4.8 has plenty of power. With the right gear ratio, I think you'd be surprised how well it pulls. Besides, it doesn't have that cylinder deactivate crap to worry about. Maybe I'm old school, but I still remember what you could get away with pulling with a 90 HP straight 6 cylinder in a pickup.

300 Ford straight 6 and a four speed. Yum!