What rear end gear oil?

[03chevytruck]

Waht gear oil should i get? 75W90 or 85W140?

[RedHeartbeat]

75w90 and no synthetics with an Auburn, they require petroleum oils only with a friction modifier additive that will come with the diff.

[Srt8Jeep]

1. 5W-30 is preferred.
2. GL-4 is a synthetic gear oil, GM part no. 12346190.
3. GLS is a special gear lube, GM part no. 12345349 (5-SPD).
4. GLS is synthetic lubricant; use only GM part no. 12378557
5. 80W-90 GL-5 is a synthetic lube; GM part no. 1052271.
6. Do not use synthetic lubricant in axles using RTV sealant.
Synthetic lubricant will chemically atack RTV sealant.
7. GLS is synthetic lubricant; use only GM part no. 12378557
8. Do not add friction modifier.
9. SLF is GM part no. 12378508 (U.S.), 10953626 (CAN).

This link will give you all the stuff Amsoil offers for your truck:
AMSOIL ONLINE PRODUCT APPLICATION GUIDE - amsoiloaf.852294
2003 CHEVROLET TRUCKS SILVERADO 1500 PICKUP 5.3L 8-cyl Engine Code T

FILTERS
Oil Filter......... EAO32 AMSOIL Ea Oil Filter
Oil Filter......... 51042 WIX 51042 Oil Filter (O)
Air Filter......... EAA123 AMSOIL Ea Air Filter
Air Filter......... 42487 WIX 42487 Air Filter
Fuel Filter....... 33481 WIX 33481 Fuel Filter
Trans Filter..... 58847 WIX 58847 Auto Tran Filter [1]
Trans Filter..... 58608 WIX 58608 Auto Tran Filter (O) [2]
Trans Filter..... 58837 WIX 58837 Auto Tran Filter (S) [3]
Trans Filter..... 58904 WIX 58904 Trans Filter (S) [4]
Trans Filter..... 58917 WIX 58917 Auto Tran Filter (S) [5]
Cabin Filter..... 24814 WIX 24814 Cabin Air Filter (0)

1. 4L60E - Deep Pan
2. 4L80E - Deep Pan
3. Includes pan gasket
4. 4L60E - Shallow Pan
5. 4L80E - Shallow Pan - Pan Gasket not included - If Pan Gasket required, use 58836


NGK PLUGS & WIRE SETS
Plug................. GPSERIES TR55GP NGK3403
Plug................. IXIRIDIUM TR55IX NGK7164
Plug................. VPOWER TR55 NGK3951
Wire Set.......... WIRESET RC-GMX091 NGK51033 [1]
Wire Set.......... WIRESET RC-GMX102 NGK51430 [2]

1.Mitsubishi Ign
2.Delphi Ign


TRICO WIPER BLADES
Blade Class Driver Passenger Rear
NEOFORM T16220 T16220
EXACTFIT T221 T221
WINTER T37225 T37225
OKTANE 22 inch 22 inch



LUBRICANTS & FLUIDS
Engine Oil
Grade 1......API*
Series 2000 Synthetic 0W-30 Motor Oil
SAE 5W-30 Synthetic Motor Oil
SAE 5W-30 XL Synthetic Motor Oil
Above 0°F......10W-30
All Temps......5W-30[1]
Manual Transmission,NV4500.....GLS[2]
Synthetic Manual Transmission and Transaxle Gear Lube 75W-90
Manual Transmission,NV3500.....GLS[3]
AMSOIL Synthetic Synchromesh Transmission Fluid
Automatic Transmission.....AF6
Synthetic Automatic Transmission Fluid
Differential, Front Full time 4WD.....GLS[4]

Severe Gear 75W-90
Differential, Front Selectable 4WD.....GL-5[5][6]
All Temps......80W-90
SAE 80W-90 Synthetic Gear Lube
Severe Gear 75W-90
SAE 75W-90 Synthetic Gear Lube
Differential, Rear Others.....GLS[7]

Severe Gear 75W-90
Differential, Rear W/ QS4 Axle.....GLS[7][8]

Severe Gear 75W-90
Transfer Case,NVG 149.....AF3
Synthetic Automatic Transmission Fluid
Torque-Drive™ Synthetic Automatic Transmission Fluid (ATD)
Transfer Case,NVG 261/263.....AF3
Synthetic Automatic Transmission Fluid
Torque-Drive™ Synthetic Automatic Transmission Fluid (ATD)
Transfer Case,NVG 236/246.....SLF[9]
No AMSOIL Product Recommendation
Fluids
Power Steering Fluid.....PS
Brake Fluid.....HB
Clutch Fluid.....HB

1. 5W-30 is preferred.
2. GL-4 is a synthetic gear oil, GM part no. 12346190.
3. GLS is a special gear lube, GM part no. 12345349 (5-SPD).
4. GLS is synthetic lubricant; use only GM part no. 12378557
5. 80W-90 GL-5 is a synthetic lube; GM part no. 1052271.
6. Do not use synthetic lubricant in axles using RTV sealant.
Synthetic lubricant will chemically atack RTV sealant.
7. GLS is synthetic lubricant; use only GM part no. 12378557
8. Do not add friction modifier.
9. SLF is GM part no. 12378508 (U.S.), 10953626 (CAN).


CHASSIS LUBRICATION
Two-wheel drive
6 Fittings, 0 Plugs..........LB
Series 2000 Synthetic Racing Grease
Synthetic GHD Heavy-Duty EP Grease
Synthetic Multi-Purpose Grease NLGI #2
Four-wheel drive
11 Fittings, 0 Plugs..........LB
Series 2000 Synthetic Racing Grease
Synthetic GHD Heavy-Duty EP Grease
Synthetic Multi-Purpose Grease NLGI #2



CAPACITIES
Engine, with filter..........6.0 quarts[1]
Cooling System, W/ AT & Optional AC Initial Fill..........15.0 quarts
AMSOIL Antifreeze and Engine Coolant
Cooling System, W/ AT Initial Fill..........13.0 quarts
AMSOIL Antifreeze and Engine Coolant
Automatic Transmission, 4L80E Initial Fill..........7.7 quarts[2]
Automatic Transmission, 4L60E Initial Fill..........5.0 quarts[2]
Automatic Transmission, Total Fill
4 speed 4L60E..........11.0 quarts
4 speed 4L80E..........14.0 quarts
Manual Transmission, NV3500 (SEC)..........4.2 pints[3]
Manual Transmission, NV4500 (TOPC)..........7.8 pints
Differential, Front..........3.6 pints
Differential, with 11 ring gear Dana Rear..........8.4 pints
Differential, with 9.5 ring gear Amer Rear..........5.5 pints
Differential, with 10.5 ring gear Amer Rear..........5.5 pints
Differential, with 11.5 ring gear Rear..........7.6 pints
Differential, with 9.75 ring gear Rear..........5.9 pints
Differential, American 8.6 ring gear Rear..........4.2 pints
Differential, American 8.5 ring gear Rear..........4.2 pints
Transfer Case,NVG 149..........4.4 pints
Transfer Case,NVG 236/246..........4.0 pints
Transfer Case,NVG 261/263..........4.0 pints

1. After refill check oil level.
2. With engine at operating temperature, shift through all
gears. Let engine idle in PARK for at least 3 minutes. CK
level and add fluid as needed.
Do not overfill.
3. Approximate, fill to level of fill plug.


TORQUES
Oil Drain Plug.....18 ft-lbs
Manual Transmission NV3500
Fill Plug.....22 ft-lbs
Drain Plug.....22 ft-lbs



SERVICE INTERVAL
AMSOIL Product Recommendation and Drain Interval Guide (g1490)

OTHER TOP QUALITY PRODUCTS
Mothers® Car Care Appearance Products
By-Pass Oil Filters

[RedHeartbeat]

Awesome information!

Always remember to use the fluids recommended by the differential manufacturer. The instructions from Auburn says you will void their warranty if you use synthetic fluid in their diffs. GM axles use synthetic fluids and a paper gasket on the cover. The cover gasket is almost imposssible to find anywhere but the dealership. Auto parts stores will try to sell you silicone to seal the rear end. Don't do it. The previous post backs up this fact. Paper seals better, anyway. Don't forget to add the friction modifier(I read somewhere that it's actually whale fat! )

[txarkitekt]

Damn Wade...you need to give us more information next time! It's pretty easy guys--just follow manufacturer specs...

[Srt8Jeep]

Sorry I got carried away

[txarkitekt]

Sorry I got carried away

Just don't let it happen again...

[4doorvett]

A lot of good info there.

Transfer Case,NVG 149.....AF3
Synthetic Automatic Transmission Fluid
Torque-Drive™ Synthetic Automatic Transmission Fluid (ATD)
Transfer Case,NVG 261/263.....AF3
Synthetic Automatic Transmission Fluid
Torque-Drive™ Synthetic Automatic Transmission Fluid (ATD)
Transfer Case,NVG 236/246.....SLF[9]

So I should use synthetic ATF in my transfer case?