Rear end oil

[BigSix]

Just did the 30k mile rear end lube change with Mobil 1 75w-90 full synthetic. It held 3.5 qts to the bottom of the fill hole. Then I looked in the shop manual and it says fill capacity for the 10.5 AAM is 4.75 pints or just below 2.5qts. Then I looked in my shop manual for my '95 Dodge/Cummins and it says fill level is 1" below the fill hole. In bold it says "Caution, over filling can cause foaming and over heating". I replaced a seal in my '98 Dodge Cummins and have replaced one in my '03. It seems I've been over filling my axles thinking I was doing good. I went out this morning and sucked a qt out and fill level is now about 3/4-1" below the fill hole. I can see the reasoning for this as we don't really want the chunk slapping the oil at 700rpm. That would whip it into a suds in no time. We just want the ring to pick up oil as it dips in it. It'll splash into everything else as needed. Just wanted to pass those thoughts along...

 

[Whit]

Bigsix, thanks for the info, my only quandry here is I was under the impression that the 10.5 was a standard for the gassers and with the Cummins option they mandate the 11.5 rearend??? I know my womans new 04.5 had the 10.5 listed first then the optional 11.5 was included when the Cummins went in??? Check yer options to make sure on this..........let us know cuz now I am

Cheers, Kevin

 

[BigSix]

My '03 is a standard output with a 47RE automatic. They came with a 10.5. The HO 6spd 2500 and the 3500 came with a 11.5 even with the HEMI. Now that there's no SO, all Cummins 2500s and HEMI or Cummins 3500s come with 11.5s. I should'a waited a year.

 

[Redhawk]

Bigsix, I have the same combo you have. When you change the fluid do you need a new gasket for the rear end? I am due for the same service soon. Thanks.

 

[MUDDY]

dave,

if my memory is correct rvt silicone is what is on the aam 10.5 cover. good to see ya at oilburners

 

[holtzer1]

the new AAM axles REQUIRE full synthetic fluid...filled to 1" below the plug hole, ltd slip additive is optional, not needed but a good mix of additives just to be on the slippery side.