Need help on LB7 oil chang

[buellxb]

Hi,
I got a 04 LB7 and I did not get the manual with my truck. Can some body help me with fluid amounts and wieghts I should buy. I am planing on getting all mobil1 stuff just need to know how much the engine and trans and the diffs and the tranfercase hold. Thanks for the help. Brian

[DmaxMaverick]

Engine oil: 10 qts, 15w-40 CI-4 (CH-4 at a minimum). In very cold climates, 5-30/40 or 0-30/40 can be used. Synthetic 5-40 is fine, which is what you will probably find in the M-1, just be sure you get the "CH" or "CI" and the 40 part correct.

Most name brand or commercial brand oil filters are OK. Just steer away from Fram!!

Tranny: Dexron III or later. ~8 qts. for a drain/fill service. 20-22 qts. for a full flush. Change the spin on filter only (don't forget the magnet!!). The internal filter need only be changed at overhaul, and the pan does not need removal (it has a drain plug).

Transfer case: ~2 qts, same fluid you use in the tranny. Fill to fill hole.

Front diff: OEM is 85-90 gear lube. 75-90 synthetic is fine. About 2 qts. filled to fill hole.

Rear diff: OEM fill is 75-90 synthetic. About 3.5 qts. For "normal" driving and towing/hauling, 75-90 synthetic. For heavy tow/haul, or very hot climates, 75-140 synthetic may be better. The rear diff has a drain plug, so you don't have to remove the cover. Fill it to about 1/2" below the fill hole, with the truck sitting on level ground. Don't get excited when you see the "junk" that will come out. It's normal. The drain plug is magnetic, so be sure to clean it. While you are under there, check your vent tube. It should be at a constant incline from the diff. If it has any dips or loops, it can cause blockage, then seal leakage.

[buellxb]

Thanks for the help, I got all GM filters and the allison filter to do my service. Thanks, Brian

[tomking]

Speaking of oil changes, what is the typical mileage between O/F changes for the LB7?

Tom
2002 2500HD Ext cab D/A

[DURAMAN]

Maverick -

You mention using Tranny Fluid in the TC. I have seen others post the same, however I've changed mine two times now and both times the dealer gave me this blue stuff. Is the blue stuff really necessary or is GM just trying to make some extra money off those of us who are uninformed?

Thanks!
Shane

[DmaxMaverick]

The "blue stuff" is Autotrac II fluid. If you don't have Autotrac, you are paying way too much for fluid, and possibly shortening the life of your TC.

Autotrac is only available on 1500's and 2500LD's. The HD's and 3500's do not have Autotrac as an option. Electric (push button) 4 x 4 is not Autotrac. If you have Autotrac, you will have an "Auto 4 x 4" button in addition to any other buttons. Electric 4 x 4 is a manual transfer case, with electric motors for engagement.

Dexron III (or higher) is the recommended fluid for all GM transfer cases, except for Autotrac.