AMSOIL Synthetic Water-Resistant Grease
AMSOIL Synthetic Water-Resistant Grease (GWR) is an NLGI #2 extreme-pressure grease built on synthetic base oils and a calcium sulfonate complex thickener for wet-duty service. The grade is engineered for boat trailer wheel bearings, jet ski steering, agricultural implements, ATV and UTV pivot points exposed to mud, and marine, agricultural, or industrial bearings exposed to standing water, immersion, or pressure wash-down. It meets the NLGI GC-LB performance grade and carries the HPM+WR (High Performance Multiuse with Water Resistance) tag from the National Lubricating Grease Institute.
Water-washout and sprayoff resistance
Calcium sulfonate complex thickener pairs with extra durable cohesive and adhesive chemistry to keep the grease in place when components are exposed to standing water, mud, snow, or pressurized spray. The film holds together during prolonged water contact and clings tenaciously to metal surfaces when wet, protecting bearings, U-joints, and chassis points through repeated immersion and wash-down cycles. Water washout in ASTM D1264 measures 0.8 percent, a low number that explains why the grease stays in wheel bearings on boat trailers that are repeatedly backed into salt or fresh water.
Corrosion protection for wet and marine service
Frequent or prolonged water contact promotes rust, accelerates pitting, and shortens bearing life. The formulation seals metal surfaces and chemically fights corrosion, passing the ASTM D1743 Rust and Corrosion Test required for NLGI GC-LB certification. The result is dependable protection for boat trailers, jet ski steering, snowmobile suspension points, ATV and UTV pivots, and industrial bearings exposed to wash-down or condensation.
Load-carrying and extreme-pressure performance
Heavily loaded wheel bearings, fifth wheels, agricultural implement pivots, and shock-loaded chassis points need a grease that does not break down under pressure. The Synthetic Water-Resistant Grease formula carries a Four-Ball EP Weld Point of 620 kgf in ASTM D2596 and a Timken OK Load of 65 lbs in ASTM D2509, both well above general-purpose grease norms. The same formula posts a 0.42 mm Four-Ball Wear scar in ASTM D2266, which reflects the strong boundary film that protects metal surfaces from sustained and sudden shock loads.
Thermal stability and dropping point
Calcium sulfonate complex thickeners hold their structure at high temperature, which keeps the grease working in trailer hubs that heat up on long highway runs and on industrial bearings near hot process lines. The grease has a dropping point greater than 600 F (316 C) in ASTM D2265 and a high-temperature life of 120 hours in the ASTM D3527 wheel bearing test. Operating range runs from -40 F to 350 F (-40 C to 177 C), and low-temperature torque measures 8.7 N m at -40 C in ASTM D4693, supporting cold-weather service on snowmobile suspension and outdoor industrial equipment.
Mechanical and oxidation stability
Worked penetration in ASTM D217 (worked 60 strokes at 25 C) is 275, confirming the NLGI #2 grade structure. Oil separation in ASTM D6184 is 0 percent and leakage in the ASTM D4290 wheel bearing leakage test is 2.3 g, meaning the grease stays in the housing rather than purging into surrounding components. Base oil viscosity at 40 C is 170 cSt, which gives the grease a heavier oil film than typical multipurpose lithium products and helps account for the strong adhesion and wear protection in wet service.
Recommended applications and service intervals
The grease is approved for any application where an NLGI #2 GC or LB grease is recommended and exposure to water, humidity, or other high-moisture conditions is common. Typical fit includes automotive and trailer wheel bearings, chassis points, boat trailer hubs, jet ski steering and trim, agricultural implement bearings, ATV and UTV suspension and pivot points, snowmobile front-end and skid frame fittings, and industrial bearings exposed to wash-down. Re-grease intervals are governed by the equipment manufacturer and the operating environment.
- Maintain bearing housings one-third to one-half full of grease and do not over-grease, since excessive packing causes heat buildup.
- Wipe grease fittings clean before injecting fresh grease to prevent contaminant ingestion.
- Supplement standard greasing intervals by cleaning and repacking housings on the maintenance schedule called out by the equipment manufacturer, especially after immersion or wash-down.
- Outside the United States and Canada, follow the equipment manufacturer's recommended grease specification and re-grease interval.
Synthetic Water-Resistant Grease is compatible with many other greases. When changing greases, clean the old grease from the housing where possible, or flush the system with a liberal amount of fresh Synthetic Water-Resistant Grease while the mechanism is in operation, then monitor for any inconsistencies. Aftermarket grease additives are not recommended.
Typical technical properties
| Property | Value |
|---|
| Thickener | Calcium Sulfonate Complex |
| NLGI Consistency Grade | 2 |
| NLGI Performance Grade | GC-LB, HPM+WR |
| Penetration (ASTM D217), worked 60 strokes at 25 C, 0.1 mm | 275 |
| Operating Range, F (C) | -40 to 350 (-40 to 177) |
| Dropping Point, F (C) (ASTM D2265) | >600 (>316) |
| High-Temperature Life, hours (ASTM D3527) | 120 |
| Water Washout, percent (ASTM D1264) | 0.8 |
| Rust and Corrosion (ASTM D1743) | Pass |
| Oil Separation, percent (ASTM D6184) | 0 |
| Leakage, g lost (ASTM D4290) | 2.3 |
| Four-Ball Wear Test, mm scar (ASTM D2266) | 0.42 |
| Four-Ball EP Weld Point, kgf (ASTM D2596) | 620 |
| Timken OK Load Test, lbs (ASTM D2509) | 65 |
| Low-Temperature Torque at -40 C, N m (ASTM D4693) | 8.7 |
| Base Oil Viscosity at 40 C, cSt | 170 |
| Color | Blue |
| Texture | Smooth with Tack |
Order AMSOIL Synthetic Water-Resistant Grease
Synthetic Water-Resistant Grease is available in a single 14 oz. cartridge , a case of ten 14 oz. cartridges , a pack of forty 14 oz. cartridges , a 35 lb. lug , and a 120 lb. keg . Using AMSOIL synthetic lubricants does not void a new vehicle or equipment manufacturer warranty, and the product is backed by the AMSOIL Limited Warranty. Match the right lubricant to a trailer, ATV, UTV, marine rig, or industrial application with the AMSOIL Vehicle Lookup Guide, compare grease grades and water-resistance options in the AMSOIL Grease Guide, then order AMSOIL Synthetic Water-Resistant Grease.
Customer reviews
Good grease wished available in smsll
This is an excellent grease. I use it all the time. I have two small grease guns that I used to use it in and it’s no longer available. Use it all the time and then wished it was still available in the small Greece tube. Great for small jobs.
By Shawn on June 19, 2026.
Would recommend this to a friend.
WR grease
Great product, used it on my Teryx when I was doing a clutch mod. Great for gaskets
By Wayne on April 18, 2026.
Would recommend this to a friend.
Trailer Grease
Works great on my boat trailer.
By Kevin from Florida on March 24, 2026.
Would recommend this to a friend.
Read all 59 reviews
Frequently asked questions
What is AMSOIL Synthetic Water-Resistant Grease used for?
The grease is built for service points exposed to water, mud, snow, or wash-down. Common applications include boat trailer wheel bearings, jet ski steering and trim, marine bearings, snowmobile front-end and skid frame fittings, ATV and UTV pivot points, agricultural implement bearings, automotive chassis and wheel bearings, and industrial bearings near wash-down or condensation.
What NLGI grade is GWR Synthetic Water-Resistant Grease?
It is an NLGI #2 grease with the NLGI GC-LB performance grade and the HPM+WR (High Performance Multiuse with Water Resistance) enhancement tag. NLGI #2 is the standard consistency for most wheel bearing and chassis applications.
What is the dropping point of Synthetic Water-Resistant Grease?
The dropping point is greater than 600 F (316 C) in ASTM D2265. High-temperature life in the ASTM D3527 wheel bearing life test is 120 hours, and the operating range runs from -40 F to 350 F.
How does Synthetic Water-Resistant Grease perform in water-washout testing?
Water washout in ASTM D1264 measures 0.8 percent. The calcium sulfonate complex thickener combined with cohesive and adhesive chemistry keeps the grease in place during standing water, immersion, and pressurized spray.
Is it compatible with other greases already in the equipment?
It is compatible with many other types of grease. When changing greases, clean the old grease from the housing when possible, or flush the system with a liberal amount of fresh Synthetic Water-Resistant Grease while the mechanism is in operation, then monitor the system for any inconsistencies. For specific compatibility questions, contact AMSOIL Technical Services.
Is Synthetic Water-Resistant Grease a good fit for boat trailer wheel bearings?
Yes. The grease meets the NLGI GC-LB wheel bearing and chassis performance grade with the WR water-resistance tag, carries a 620 kgf Four-Ball EP Weld Point and 65 lb Timken OK Load, and passes ASTM D1743 rust and corrosion testing, all of which target the repeated immersion and load cycling typical of boat trailer hubs.
Does using AMSOIL grease void a new vehicle or equipment warranty?
No. Using AMSOIL synthetic lubricants does not void a new vehicle or equipment manufacturer warranty, and Synthetic Water-Resistant Grease is covered by the AMSOIL Limited Warranty.
