Rear and front axle service?

[Adamace1]

3 hours ago, diyer2 said:

Find the amount of fluid they take and put that amount in.

Ok where is that info? 

[KARNUT]

1 hour ago, Adamace1 said:

Ok where is that info? 

Maybe you ask the service department. My last truck when I was doing the fluids I bought a suction pump and pulled the fluids. To my surprise the rear end fluid fill was different than I ever encountered. Usually you fill until it comes out, or so I thought. My truck was like an inch under. I just love it when they throw curveballs. Luckily for me it had a drain plug. I measured out and put the exact amount in, then checked. It was perfect. That was on a 20 year oil truck. My truck prior was a 92 with a stroked blown Chevy. Never changed that one. My nephew is still driving it. I don’t blame people for whatever their oil change choices are. Mine have never failed me. 

[Z45]

16 hours ago, Adamace1 said:

Yea thats what I can't find out. Where the fluid Leven should be on my front and rear axle. Tried searching on here, on Google, on YouTube. Its a mystery 

Capacity:

9.5 RG Rear 5.1 pints Capacity: 9.76 RG Rear 5.5 pints Capacity: 8.6 RG Rear 4.2 pints

Edited July 13, 2021 by elcamino

[Z45]

The AAM axles are RPO SU4 (front) and SU7 (rear).

The GMCH (General Motors Components Holding) axles are RPO SU5 (front) and SU8 (rear).

[Adamace1]

6 hours ago, elcamino said:

Capacity:

9.5 RG Rear 5.1 pints Capacity: 9.76 RG Rear 5.5 pints Capacity: 8.6 RG Rear 4.2 pints

Hummm. So now I got to figuire out what my 3.23 AAM is. Is RG ring gear? I'm lost.

Edited July 14, 2021 by Adamace1

[Z45]

Yes, RG is ring gear.

 

Edited July 14, 2021 by elcamino

[Z45]

Well its not the 9.76 because that's 3.42 as is the I4 and 4.3L V6 ratio

By deduction you have the 9.5" if its a 3.23 ratio GU5

Edited July 14, 2021 by elcamino

[Adamace1]

45 minutes ago, elcamino said:

Well its not the 9.76 because that's 3.42 as is the I4 and 4.3L V6 ratio

By deduction you have the 9.5" if its a 3.23 ratio GU5

Ok thanks. So I'll take the cover off drain it, then refill with 5.1 pints or 2.55 quarts for my rear axle.  Just got to figure out the front now...

Edited July 14, 2021 by Adamace1

[Sqrls]

GM and other manufacturers don’t list differential fluid changes, transmission fluid changes, antifreeze changes, and ball joint greasing (removed the grease nipples even) because not doing these services will usually not result in any part failures for the original owner. However, if they list the maintenance as recommended, it increases the cost of ownership for the vehicle. 
For instance, coolant changes where the first coolant change is recommended at 100,000-150,000 miles (after first owner probably doesn’t own it anymore), and then every 30,000-60,000 miles from then on. 
 

So just because it’s not listed as recommended maintenance doesn’t mean there’s no benefit to doing the maintenance. You just probably won’t have an outright failure if you don’t. 

Edited July 18, 2021 by Sqrls

[Atlas]

Easiest way to find out what axle you have (GM or AAM) is to email [email protected] and request a build sheet which will show all RPO's and supplier codes included with your truck from the factory. Make sure to include your VIN. I did this just a few weeks ago and the response was within an hour.

 

As noted above, you'll see supplier codes on the sheet for which axle was supplied with your truck, SU5, SU8, etc.

 

Then you can look up in the maintenance thread in this forum which fluid applies to your axle based on the supplier code. Surprisingly, there are different fluids spec'd between the various axles.

 

If you're going to pull the diff covers, you should have a new gasket(s) on hand anyway in case the old gasket is damaged for whatever reason, even if it is reusable. On the last generation, the rear gasket was reusable. The other option is to use a fluid pump to pull the old fluid out from the fill hole. It works pretty well, although, I prefer to pull the cover so I can wipe out the bottom of the carrier and get all the crud. I don't like reusing gaskets anyway, so I'd be likely to buy a new one.

 

You already know the fill spec. It left the factory/dealer just below the fill plug opening. You can't fill it higher than the fill plug, not without special equipment. Somewhere between the old fill level, and even with the fill plug is where you want the level. The old rule of thumb is to fill until it starts to weep out the hole. Let it settle, check, and then reinstall the plug. It's not that precise. Someone already mentioned the fill capacity above - that will help you purchase enough fluid on hand to do the fluid changes.

 

..And that's it! No, it doesn't say anywhere in the manual to change the fluid. That doesn't mean it shouldn't be done for good maintenance. What it could mean is GM has a maintenance recommendation of "run to failure" with no preventive or routine maintenance for these. The fluid and component life should last the life of the truck, at least that is the hope. There is a certain satisfaction knowing you've removed any break-in metals, that the fill level is proper, and that both plugs are operational and snugged to the correct torque. Worth every penny.

[Black02Silverado]

I changed out the fluid in both axles on my 2019 at 500 miles.  The front I sucked out the fluid.  I wasn't going to pull the cover and risk a leak. It is a tighter spot to work with up front with the power steering harness and other wires to move around to get to it than I wanted to deal with.

 

The rear I pulled the cover clean up the area and put back on using the original gasket.  Then filled it up to within a half inch from the fill hole.

 

AMSOIL's squeeze packs make adding fluid a quick easy job with no mess.

 

You can find what your vehicle takes on the  AMSOIL's look-up guide.

 

 

Edited July 23, 2021 by Black02Silverado

[Ats666]

I pulled my fill plug on the rear diff and noticed there is no magnet on it. 

Is there a magnet inside the cover or did gm get rid of it in favor of cost savings?