AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube — 1 Qt, Extended Drain, Differential/Gearbox | FGRQTC
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The AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube is an extended-drain synthetic gear oil engineered for differentials, gearboxes, heavy-duty trucks, commercial vehicles, light trucks, SUVs, motorhomes, off-road equipment, buses, tractors, and related gear-lube applications requiring a 75W-90 synthetic gear lubricant. It is designed to reduce wear, protect gears and bearings under load, help prevent rust and corrosion, improve cold-weather operation, and support longer service intervals.
Key Features
- 75W-90 full synthetic gear lube
- AMSOIL Long Life product family
- Product code family: FGR
- Common package references include FGRQT / FGRQT-EA for quart bottle and FGR1G / FGR1G-EA for gallon jug
- Engineered for extended drain intervals up to 500,000 miles / 805,000 km where approved by the equipment manufacturer
- Provides high-load gear and bearing protection
- Shear-stable formula resists viscosity loss
- Helps protect against rust and corrosion
- Supports better cold-weather shifting compared with conventional gear oils
- Helps improve operating efficiency by reducing friction-related energy loss
- Helps condition seals and support improved seal life
- Suitable for all-season use
- Recommended for over-the-road trucks, light-, medium-, and heavy-duty trucks, commercial vehicles, off-road equipment, motorhomes, autos, SUVs, emergency vehicles, buses, delivery/utility vehicles, and tractors
Application Compatibility
Use this gear lube where the equipment manufacturer specifies a 75W-90 synthetic gear lubricant and the application requirements match the product’s listed specifications. It is commonly used in axle, differential, gearbox, and heavy-duty drivetrain applications where extended-drain synthetic gear oil is suitable.
Fitment Notice
Always confirm the required viscosity grade, API/service specification, limited-slip requirements, and drain interval in the vehicle or equipment manual before use. Do not select gear oil by viscosity alone; some marine, automotive, and heavy-duty gear systems require manufacturer-specific lubricants, additives, or approvals.
When This Product Needs Replacement
Replace gear lube according to the equipment manufacturer’s service interval, or sooner if the oil is contaminated, milky, burnt-smelling, metal-filled, low, leaking, or exposed to water intrusion. Gear oil service should also be considered if the differential or gearbox becomes noisy, overheats, leaks, or has been opened for repair.
Installation Notes
Drain and refill according to the equipment manufacturer’s service procedure. Clean the fill and drain plug areas before service, inspect magnetic plugs for metal debris, replace sealing washers where required, and fill only to the specified level. For limited-slip differentials, confirm whether additional friction modifier is required before installation.
Alternate/Superseded Part Numbers
Related AMSOIL package references include:
- FGR — AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube product family
- FGRQT / FGRQT-EA — quart bottle
- FGRQT-CA — case of 12 quart bottles
- FGR1G / FGR1G-EA — gallon jug
- FGR1G-CA — case of 4 gallon jugs
- FGR05 — 5 gallon pail
- FGR16 — 16 gallon keg
- FGR55 — 55 gallon drum
- FGR27 — 275 gallon tote
Parts Desk Insight
With gear lube, the safe match is viscosity plus the required service specification. 75W-90 gets you part of the way there, but confirming the axle, gearbox, or differential requirement first helps avoid noise, chatter, overheating, or premature wear.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.