New GMC Sierra 2500 6.0L - no diff oil change rec.

[SteveSRT8]

Originally Posted By: Nate1979
Originally Posted By: hattaresguy
A lot of our GM trucks blow axle seals between 60k-110k miles so that's when they get changed. Maybe GM figures on this...



Which GM trucks are you referring to? The 2500/3500 rear axles are supposed to be pretty reliable.


The giant Dana truck rear end in the 3500 models is very durable. I have run them 500k miles without much at all except an occasional change of lube. High loads and Florida heat.

They do NOT routinely blow any seals. They basically are trouble free...

 

[Ramblejam]

Originally Posted By: used_0il
Would you like every year, HD, non HD, 2500, 3500 and engine combination?


OP purchased a 2015 GMC Sierra 2500 6.0L.

You then subseqently stated that "if people knew the difference between 2500s and 3500s, they would pick the latter just for the rear end."

So why should he have purchased a 3500 instead?

 

[hattaresguy]

Originally Posted By: Nate1979
Originally Posted By: hattaresguy
A lot of our GM trucks blow axle seals between 60k-110k miles so that's when they get changed. Maybe GM figures on this...



Which GM trucks are you referring to? The 2500/3500 rear axles are supposed to be pretty reliable.



The half tons pop them all the time, and I have seen a number 2500HD's do it as well.

Other than that GM's are pretty bomb proof, which is why I'd say 80% of my contractors run a GM truck of some sort.

 

[Hootbro]

FWIW, both GMC/Chevy and RAM use an 11.5" derived axle from AAM.

In my RAM manual, they list just a fluid level inspect for normal service but call out a 20K mile change interval for severe service.

 

[Nate1979]

I think mine has the 10.5". My understanding is the 10.5" doesn't have a drain plug on the back cover (mine doesn't) and the 11.5" does. My understanding is that GM uses both and the bigger one goes on the higher output application (Duramax and 3500's? Not sure).

 

[Hootbro]

Originally Posted By: Nate1979
I think mine has the 10.5". My understanding is the 10.5" doesn't have a drain plug on the back cover (mine doesn't) and the 11.5" does. My understanding is that GM uses both and the bigger one goes on the higher output application (Duramax and 3500's? Not sure).


The 11.5" AAM axles on the RAM do not have a drain plug, just filler plug so you have to un-bolt the cover and drain that way.

Either way, no service interval either normal or severe is wack. I would just make up my own interval like every 20K-30K and go with that.

 

[userfriendly]

I have a 2500 Duramax and the light duty diff. That was not supposed to happen.

A few years back you could buy a 1500 HD with an 8 bolt wheel pattern on 165mm. Mine are 8X180 mm.

 

[cronk]

I prefer a initial change around 15k to remove break in wear metals. After that, with a good synthetic, 30k severe service, 40-50k under light service.
I know some will say that's overkill.

 

[userfriendly]

My error on the above. 2015 shows same diff on HD 2500 and 3500 pickups.
Prior, the Dmax got the big diff and 6.0 gasoline got the little diff on 2500s....3500 got the big un with all engines.
But there is non HD 2500 express vans, Yukons, Suburbans etc that likely have the light weight diff.

Correction; post should have read; When shopping for an older truck, you might get a locker diff worth $600.00 in a truck that cost $500.00

 

[Ramblejam]

Sure, the 1050/1150 axles are stout, but the semi-float, 8-lug, 14-bolt AAM 950 is no slouch -- unless you put it behind a monster motor, it will survive constant abuse.

 

[userfriendly]

All here

www.dana.com

 

[Ram01]

Gm Diff fluid is top notch

 

[Gasbuggy]

There is too much competition for low cost of ownership status and no chance GM will eat a diff under warranty because of a fluid related failure. You have to consider their goals are not the same as yours. I would probably follow a 100k interval if it were my truck.

 

[clinebarger]

Originally Posted By: Nate1979
I think mine has the 10.5". My understanding is the 10.5" doesn't have a drain plug on the back cover (mine doesn't) and the 11.5" does. My understanding is that GM uses both and the bigger one goes on the higher output application (Duramax and 3500's? Not sure).


Yeah, You have a 10.5" GM Corporate 14-bolt...Now built by AAM, Very good differential, Been around since 1973. It's amazing that GM is still using it....They are expensive to manufacture, Having a "Drop-Out" Pinion & a Pinion support bearing, The center section is probably STRONGER than a AAM 11.5 or a Dana 70/80, The Axle tube diameter is the only reason they don't get used in Diesel & 3500 models since 2001.

Dodge also uses a 10.5" axle in their gas 2500's., But was designed by AMM from sratch, Completely different axle. Early '03/'04 250hp Cummins 2500 trucks also used this axle.


Dodge & GM share the AAM 11.5" axle in their Diesel 2500 & 3500's. My GM 11.5 has a drain at the bottom of the Case. Dodge versions do not.

 

[hattaresguy]

Most of the guys that work for me never change them. The rear ends usually leak around 150k so they get changed by default.

Those trucks pretty much will go 200k-300k on nothing but oil changes and maybe 1 spark plug change and a couple air filters. Very low maintenance vehicles.

 

[Nate1979]

Originally Posted By: clinebarger
Originally Posted By: Nate1979
I think mine has the 10.5". My understanding is the 10.5" doesn't have a drain plug on the back cover (mine doesn't) and the 11.5" does. My understanding is that GM uses both and the bigger one goes on the higher output application (Duramax and 3500's? Not sure).


Yeah, You have a 10.5" GM Corporate 14-bolt...Now built by AAM, Very good differential, Been around since 1973. It's amazing that GM is still using it....They are expensive to manufacture, Having a "Drop-Out" Pinion & a Pinion support bearing, The center section is probably STRONGER than a AAM 11.5 or a Dana 70/80, The Axle tube diameter is the only reason they don't get used in Diesel & 3500 models since 2001.

Dodge also uses a 10.5" axle in their gas 2500's., But was designed by AMM from sratch, Completely different axle. Early '03/'04 250hp Cummins 2500 trucks also used this axle.


Dodge & GM share the AAM 11.5" axle in their Diesel 2500 & 3500's. My GM 11.5 has a drain at the bottom of the Case. Dodge versions do not.





Great info. Thanks for sharing.

 

[DoubleWasp]

Drain is a good thing to have once you get a look at the price of an AAM 11.5" cover gasket.