AMSOIL guide
AMSOIL Grease Guide
AMSOIL builds a full synthetic grease lineup split by application: Synthetic Polymeric Off-Road Grease for skid steers, excavators, and construction wheel bearings; Synthetic Polymeric Truck Chassis Grease for pickup and trailer wheel bearings, U-joints, and kingpins; Synthetic Multi-Purpose Grease as the general-shop pick; and specialty greases for water exposure, semi-fluid gear cases, 5th-wheel plates, and food-processing applications. Most options ship in NLGI 2 consistency, with NLGI 1 available for cold-climate pumping or centralized grease lines. Cartridges fit standard grease guns; 35 lb and 120 lb pails fit bulk dispensers and shop reels.
Choose the right NLGI grease grade
The National Lubricating Grease Institute's consistency scale runs from 000 (almost fluid) to 6 (block grease). The numbers describe how much the grease deforms under a standardized cone-penetration test. NLGI 2 is the global default for automotive and industrial grease points, including wheel bearings, U-joints, kingpins, and chassis fittings. NLGI 1 is softer and is the pick for centralized grease systems with long delivery lines, cold-climate hand-pumping, and any application where pumpability matters more than stay-in-place.
Going softer than the application calls for, the grease slings out under load. Going stiffer than the application's pump can move, the grease starves the bearing during the resupply stroke. Match the NLGI grade to the equipment's lubrication system, not just the bearing.
AMSOIL synthetic grease lineup by application
| Grease | Best fit | Where to buy |
|---|---|---|
| Synthetic Polymeric Off-Road NLGI 2 | Skid steer, excavator, dozer, construction wheel bearings, pins, bushings | Buy online | Product details |
| Synthetic Polymeric Off-Road NLGI 1 | Same applications in cold climates or centralized systems | Buy online | Product details |
| Synthetic Polymeric Truck Chassis NLGI 2 | Pickup and trailer wheel bearings, U-joints, kingpins, 5th-wheel plate | Buy online | Product details |
| Synthetic Multi-Purpose | General automotive and shop use, chassis lube, light-duty bearings | Buy online | Product details |
| Synthetic Water-Resistant | Marine trailer bearings, boat lift, water-exposed equipment | Buy online | Product details |
| Synthetic High-Viscosity Lithium-Complex | Heavy-duty industrial bearings, high-temperature applications | Buy online | Product details |
| Synthetic EP 00 | Semi-fluid gear cases, enclosed gear drives that leak with oil | Buy online | Product details |
| X-Treme Synthetic Food-Grade | NSF H1 food-processing equipment | Buy online | Product details |
Why polymeric grease handles shock and water better
A conventional NLGI 2 grease relies on its soap-thickener structure to hold the base oil in place between the bearing's rolling elements. Under heavy shock load, water spray, or aggressive cornering, that structure breaks down faster than it can re-form, and the grease slings out of the bearing.
Polymeric grease adds a tackifying polymer that physically clings the lubricant film to the steel surface. The polymer is what lets the same NLGI 2 consistency hold position on a skid-steer pin, a trailer wheel bearing that just ran through a salt-water boat ramp, or a 5th-wheel plate at 110°F. The trade-off is a slightly higher base price; the payoff is longer regrease intervals and less collateral damage when a fitting gets missed on a service round.
Where AMSOIL polymeric grease earns its place
Stays in the bearing under shock
Tackifying polymer holds the lubricant film on the steel during impact loading, off-road jolts, and hard cornering.
Water wash-off resistance
Resists salt water, mud, and rain on boat trailers, snowplow front ends, and farm equipment that ends a workday under the hose.
Wide-temperature stability
Dropping point above 500°F means the grease does not flow off the bearing in summer braking or hot-loaded trailer service.
EP additive package
Extreme-pressure chemistry protects pins, bushings, and 5th-wheel plates under sliding contact and shear load.
Pumps cold (NLGI 1)
NLGI 1 version flows through centralized grease lines and 14 oz gun cartridges at low ambient temperatures.
Cartridge, pail, and drum sizing
14 oz cartridges, 35 lb pails, 120 lb kegs, and 400 lb drums match shop, fleet, and dealer-yard use without changing formulations.
How to pick the right grease in four questions
What is the equipment?
Off-road, construction, farm, skid steer: Polymeric Off-Road. Pickup, trailer, light truck, 5th wheel: Polymeric Truck Chassis. General shop, automotive: Multi-Purpose. Marine trailer, boat lift, water exposure: Water-Resistant.
What NLGI grade does the lube system need?
Hand-pumped gun cartridge or single fitting: NLGI 2. Centralized auto-lube system or cold-climate pumping: NLGI 1. Enclosed semi-fluid gear case: EP 00.
What is in the bearing now?
Lithium or lithium-complex thickener: compatible with AMSOIL polymeric and multi-purpose greases. Polyurea, clay, or calcium-complex thickener: purge the bearing through with new grease until clean material flows out before consolidating.
Any special environment?
NSF H1 food processing: X-Treme Synthetic Food-Grade. Continuous high-temperature industrial: High-Viscosity Lithium-Complex. Water-exposed marine: Water-Resistant.
Synthetic grease vs conventional lithium grease
Conventional NLGI 2 lithium grease covers most automotive grease points and works fine when the regrease interval is short and the operating environment is mild. The trade-offs show up under load: lower dropping point, weaker water wash-off resistance, and the soap-thickener structure breaks down faster under shock.
AMSOIL synthetic greases use a lithium-complex thickener (or aluminum-complex on certain specialty products) with synthetic base oil. The complex thickener raises the dropping point well above 500°F, the synthetic base oil resists oxidation across a wider temperature band, and the polymeric variants add a tackifier that conventional grease cannot match. The payoff is longer regrease intervals, fewer ruined bearings on the back forty, and quieter chassis fittings on a 200,000-mile pickup.
Bottom line: which AMSOIL grease should you use?
- Pickup, trailer, 5th wheel, U-joint, kingpin. Pick AMSOIL Synthetic Polymeric Truck Chassis Grease NLGI 2 (also online from AMSOIL).
- Skid steer, excavator, farm, construction wheel bearings, and pins. Pick AMSOIL Synthetic Polymeric Off-Road Grease NLGI 2.
- General automotive, light-duty shop work. Pick AMSOIL Synthetic Multi-Purpose Grease.
- Marine trailer, boat lift, water exposure. Pick AMSOIL Synthetic Water-Resistant Grease.
- Semi-fluid gear case or enclosed drive. Pick AMSOIL Synthetic EP 00 Grease.
Save on AMSOIL with Preferred Customer pricing
AMSOIL Preferred Customer membership is $20 USD per year ($10 USD for a six-month trial) and unlocks up to 25% off on every product, with free shipping on qualifying orders over $100. Add the membership to the same cart as your order and qualifying products switch to member pricing on that checkout, with no separate sign-up step. See the breakdown on the AMSOIL Preferred Customer page, or sign up directly through the AMSOIL Preferred Customer enrollment page.
AMSOIL grease FAQ
What does NLGI 2 mean?
NLGI is the National Lubricating Grease Institute's consistency scale. Lower numbers are softer (semi-fluid or fluid), higher numbers are stiffer. NLGI 2 is the standard automotive and industrial consistency, roughly the texture of peanut butter at room temperature. NLGI 1 is softer and pumps more easily in cold weather or long centralized grease lines. NLGI 00 and 000 are semi-fluid greases used in gear cases that are too leaky for oil but too tight for a stiff grease.
What is polymeric grease and why does AMSOIL use it?
Polymeric grease uses a tackifying polymer in addition to the soap-thickener and base oil. The polymer makes the grease cling to the steel surface instead of sling off under shock load. AMSOIL's polymeric grease family (Off-Road and Truck Chassis) holds in wheel bearings, U-joints, kingpins, and 5th-wheel plates that see heavy shock, hard cornering, and water wash-off.
Which AMSOIL grease for wheel bearings?
For pickup, SUV, light truck, and trailer wheel bearings, AMSOIL Synthetic Polymeric Truck Chassis Grease NLGI 2 is the standard pick. For off-road, skid steer, excavator, and construction wheel bearings, AMSOIL Synthetic Polymeric Off-Road Grease NLGI 2 carries the higher load and water rating. Both deliver the dropping point and EP protection wheel bearings need.
Which grease for a 5th-wheel plate?
A 5th-wheel kingpin and plate take huge shear load and shed grease aggressively. AMSOIL X-Treme Synthetic Polymeric Truck and Equipment Grease (or the heavier Synthetic 5th Wheel Grease) is the matched pick: extreme-pressure additive package, polymer tackifier for adhesion, and a high dropping point so the grease does not flow off the plate on a hot summer haul.
Are AMSOIL greases compatible with what is in there now?
Most AMSOIL synthetic greases are built on a lithium-complex thickener, which is compatible with most lithium and lithium-complex greases already in service. Mixing across thickener families (calcium, polyurea, aluminum-complex, clay) is the bigger risk, because the wrong combination can thicken, soften, or separate. Best practice on a switch is to purge the bearing with a few full strokes of the new grease until clean material flows out.
How often should I grease a U-joint or kingpin?
Most pickups and light trucks call for a U-joint and steering grease at every oil change or every 5,000 to 7,500 miles, with shorter intervals for plowing, towing, and off-road service. A polymeric grease can stretch that interval because it stays in place longer; verify against the OEM service manual.
What does the dropping point on a grease label mean?
Dropping point is the temperature at which the grease loses its thickener structure and starts to flow like an oil. AMSOIL polymeric greases run a dropping point above 500°F, which is well above any normal wheel bearing or chassis operating temperature. The higher the dropping point, the more headroom against grease meltdown in heavy braking or summer-load conditions.
Where do I buy AMSOIL grease?
Order online from AMSOIL on the grease page, which lists Polymeric Off-Road, Polymeric Truck Chassis, Multi-Purpose, Water-Resistant, Heavy-Duty, EP 00, and food-grade options. The matching grease overview on Synthetic Oil Distributor covers the same lineup with side-by-side spec comparisons.
Order AMSOIL synthetic grease
Order online from AMSOIL's grease page. To unlock up to 25% off, add an AMSOIL Preferred Customer membership to the same cart and qualifying products switch to member pricing immediately, with no separate sign-up step.