Changed the front and rear diff fluid this weekend, a small amount of metal in the front and 1/2 a qt low to boot:( , did the rear and it was clean but it was also low- 1 1/2 QTS:mad: , and this was after I asked the dealer to make sure it was checked on the PDI. Called them today and got no where. Just Censored me off.
So all you new truck owner better check yours!

Not to worry at all. Mine was the very same way and I checked into it 100% only to find out that full is about 3/4" below the fill plug!!!!!!! Yes, that seems crazy, but thats how they are designed to work.
DAN

So the key ? is do we fill it all the way up like the 03 and earlier or leave it down like the 04 and up manuals say.

It is the same rear end.

Eric give us your imput?

I filled mine to just below the threads w/ schaeffer's syn.moly.

Sounds like another GM cost savings...lol.

This was on the GM TechLink Website for February concerning Rear Axle Fill Level. When you are changing and refilling, do as you like, but this helps to explain what is coming from the factory.


On 2005 Chevrolet Silverado and GMC Sierra 2500/3500 Series Pickups equipped with the 11.5-inch ring gear rear axle assembly, the factory lubricant fill level may appear lower than the published specification. This axle can be identified by the location of the fill plug on the rear axle housing cover, instead of on the front of the axle housing.

During production, all axle assemblies are filled by volume of fluid. They are not filled to reach a certain level. On the 11.5-inch rear axle, the fill quantity is 3.0 liters +/- 0.1 liter (3.18 quarts +/- 0.1 quart). With the correct amount of fluid in the axle, the fluid level may be as much as 35 mm (1.4 in.) below the bottom of the fill plug. The published specification is 17--21 mm (0.6--0.8 in.) below the fill plug opening.

TIP: It is NOT necessary to add axle fluid when the fluid level is at or above 35 mm (1.4 in.) below the bottom of the fill plug.

On any rear axle, variations in the readings can be caused by factory fill differences between the minimum and maximum fluid volume. Also, if a vehicle has just been driven before checking the fluid level, it may appear lower than normal because fluid has traveled out along the axle tubes and has not drained back to the sump area. A reading taken five minutes after the vehicle has been driven will appear to have a lower fluid level than a vehicle that has been stationary for an hour or two.

TIP: The rear axle assembly must be supported to get a true reading.

A revised bulletin will include service fill levels and fill amounts.

I still do not understand how the same axle gets less fluid every year.

When new I drained a little over 2 quarts from the rear and about 1 quart from the front.

I filled them to the Brim..Scr...w what GM says.

Yea- why publish a fluid capacity and then don't use it, be just like GM to say Oh so sorry no warranty because you were low on fluid. The owner manual says 2 qt front and 4 qts rear, thats what should be in it form the factory.

I was told that they are filled low from the factory due to break in of the diff. Mine was low, very low when I changed it a 500miles. It also smelled terrible.