[Spartan]

I'm attempting to ID the capacity of the differential capacity. I was expecting to maybe find an ID tag or stamp on the rear axle but I didn't. I've tried looking it up online but I can't find the RPO code that tells me what I'm looking for.
I did happen to find a chart that said the capacity is 4.2 pints or 5.5 pints depending on the ring gear, but I don't know what RG I have.

The truck is a 2014 Sierra, 5.3L w a 3.42 rear dif, and if it matters, the diff cover has 12 bolts.

 

[19trax95]

You have the smaller ring gear. The larger one is for the 6.2l motor.

So I'd get 5 quarts and fill it until it is level with the fill hole. The spec is something like 3/8" below the fill hole, but I've never gone by that and have never had an issue. But it also probably doesn't hurt to have it at what gm says.

 

[EKinMN]

Capacity should be in your manual. Here's the process:
How to Change Rear Differential Fluid

 

[Spartan]

I was guessing that I have the smaller RG since I have a 5.3L, but I didn't know if the RG size was maybe dictated by anything else.

 

[wildchevy]

You have the smaller ring gear. The larger one is for the 6.2l motor.

So I'd get 5 quarts and fill it until it is level with the fill hole. The spec is something like 3/8" below the fill hole, but I've never gone by that and have never had an issue. But it also probably doesn't hurt to have it at what gm says.

All the max tow nht trucks got the larger ring gear too regardless of engine size, 5 Quarts maybe a little to much to buy,

 

[Spartan]

I caught my mistake. I had a typo in my first post. It's pints. Not quarts.

 

[Z15]

My info shows for 2014 up;
8.6" ring gear has 10-bolt cover
9.5" ring gear has 12-bolt cover (Max Trailering has 9.76" RG '14 up)