75W-90 Long Life Synthetic Gear Lube 

Specifically Engineered for 500,000-Mile Service Life in Over-the-Road Trucks – In stock in the Five Gallon Bucket

The Differential Gear Lube that earns us plenty of repeat business

Extended-drain lubricant engineered to last longer and protect gears better than conventional gear oils. Reduces wear, conditions seals and helps prevent rust. Promotes longer equipment life and reduced maintenance costs.

Long Life Synthetic Gear Lube 75W-90AMSOIL’s Long Life Synthetic Gear Lube 75W-90 is an extended-drain gear lube engineered to last several times longer and protect gears better than conventional gear oils. This exclusive AMSOIL formulation of premium synthetic base oils and high-performance additives resists acid, carbon and varnish formation from oxidative breakdown. Components run cleaner and last longer. AMSOIL Long Life Synthetic Gear Lube is shear-stable and reduces friction. It maintains its viscosity during extended service for maximum wear control and is fuel-efficient. The superior cold-temperature fluidity and high-temperature stability properties of AMSOIL Long Life Synthetic Gear Lube make it excellent for all-season use. AMSOIL Long Life Synthetic Gear Lube helps extend equipment life and reduce maintenance costs.

Download or print the 75W-90 Product Data Bulletin

Download PDFProduct Datasheet

 

Buy & Check PriceAnd Container Size

Gear Lube ApplicationsAPPLICATIONS

AMSOIL Long Life Synthetic Gear Lube, in the correct viscosity grade, delivers excel
lent protection in domestic and foreign applications, including over-the-road trucks;
light-, medium- and heavy-duty trucks; off-road equipment; commercial vehicles;
motorhomes; autos; SUVs; emergency vehicles; buses; delivery/utility vehicles and
tractors.

Use AMSOIL Long Life Synthetic Gear Lube in differentials, manual transmissions or other gear applications where one or more of the following standards are specified: API GL-5 & MT-1, MIL-PRF-2105E, Dana SHAES 234 (Formerly Eaton PS-037) for 250,000 miles, Dana SHAES 256 (Formerly Eaton PS-163) for 500,000 miles, Dana SHAES 429A, Mack GO-J & GO-J+, Meritor 0-76N (75W-90) & 0-80 (80W-140) plus hypoid gear oil specifications from ZF TE-ML 07A and 08 foreign and domestic manufacturers such as GM, Ford and Daimler Chrysler. It can also be used in rear axles where API Service GL-4 lubricant is recommended.

AMSOIL Long Life Synthetic Gear Lube provides:

  • High Load Gear and Bearing Protection
  • Protection from Rust and Corrosion
  • Better Cold-Weather Shifting
  • Improved Efficiency
  • Improved Seal Life

For product service life in differentials, consult your owner’s manual or the Original Equipment Manufacturer (OEM) to establish the application, NORMAL or SEVERE.

.
Normal Service
Severe Service
Cars, SUVs, Light Trucks Drain at 100,000 miles of service or according to the owners manual, whichever is longer Drain at 50,000 miles of service or according to the owners manual, whichever is longer
Heavy Duty Class 8 Line Haul Follow the OEM drain interval (miles or hours) for synthetic oil up to 500,000 miles or three years, whichever comes first.
Vocational/Delivery Follow the OEM drain interval (miles or hours) for synthetic oil up to 120,000 miles or three years, whichever comes first.
Heavy Duty Off-Road Follow the OEM drain interval (miles or hours) for synthetic oil up to 100,000 miles or two years, whichever comes first.

For product service life in non-differential applications, consult owner’s manual or the OEM for either normal or severe synthetic oil service intervals. Where service intervals are unavailable, drain at twice the interval for conventional oil.

Note: AMSOIL does not support extended drain intervals where water contamination occurs. Check and service the gear oil frequently when water contamination is possible.

Gear oils should be changed more frequently when operating vehicles or equipment in dusty or dirty conditions unless the gear system is properly sealed and equipped with membrane-type breathers.

COMPATIBILITY

AMSOIL Long Life Synthetic Gear Lube is compatible with other synthetic and conventional gear oils. Mixing AMSOIL gear oils with other oils, however, will shorten the oil’s life expectancy and reduce its performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed.
AMSOIL Long Life Synthetic Gear Lube is compatible with most limited-slip differentials. If limited-slip differential chatter occurs, add AMSOIL Slip-Lock AMSOIL Long Life Synthetic Gear Lube 75W-90 replaces
competitors’ 75W-90 and 80W-90 viscosity grades. AMSOIL Long Life Synthetic Gear Lube 80W-140 replaces competitors’ 80W-140 and 85W-140 viscosity grades.

 

Customer Testimonials

Gear Lube
By  ELH,  a  Verified Buyer  from  NC  on  July 01, 2025
I use AMSOIL products whenever I have a need for lubrication. I even use in my bush hog gear box. Change the lube yearly and have not had a single issue with performance. I depend on AMSOIL products to make my equipment perform and last as long as possible.
Great product
By  PATRICK,  a  Verified Buyer  from  Wichita, KS  on  January 02, 2024
Going to use it in my older tractors. If it is Amsoil, it is great
Protect Your Rear End!
By  Gregory,  a  Verified Buyer  from  Washington  on  April 20, 2023
Use this exclusively in my rear diff to protect from heavy towing conditions. Pulled the cover off recently for an inspection and still looks new.