Schaeffer #238 Ultra Supreme Grease: Worth It?
Schaeffer #238 Ultra Supreme Waterproof Grease is a PAO synthetic, aluminum complex grease fortified with moly. It outperforms conventional greases in high-pressure, high-heat, and high-moisture environments—making it a strong choice for heavy-duty automotive and off-road equipment applications.
Heavy equipment doesn't forgive cheap lubrication. Bearings fail, downtime stacks up, and repair costs climb fast. Schaeffer #238 Ultra Supreme Waterproof Grease is engineered to prevent exactly that—built for operators who can't afford for things to go wrong.
Here's what sets it apart.
What is Schaeffer #238 Ultra Supreme Grease?
Schaeffer #238 Ultra Supreme is a multi-purpose, aluminum complex grease formulated from severely hydrotreated polyalphaolefin (PAO) synthetic base oils and severely hydro-finished 100% paraffin base stocks. Its high viscosity index ensures stable performance across a wide temperature range, making it reliable under conditions that would degrade standard greases quickly.
It's designed for heavy-duty automotive and off-road equipment—think construction machinery, agricultural vehicles, and fleet trucks operating under demanding loads.
How Does the Moly Fortification Benefit Equipment?
Schaeffer #238 Ultra Supreme Grease is fortified with molybdenum disulfide (moly), which acts as a solid-film lubricant between metal surfaces. When extreme pressure compresses lubricating films, moly fills in microscopic surface irregularities and prevents direct metal-to-metal contact.
The practical results are significant:
- Reduced friction, which directly lowers contact area temperatures
- Less wear on bearing surfaces over time
- Extended equipment life and longer intervals between lubrication cycles
Notably, Schaeffer #238 meets Caterpillar's 5% moly specification for grease—a benchmark that reflects real-world performance standards set by one of the world's leading heavy equipment manufacturers.
What Performance Benefits Does Ultra Supreme Grease Deliver?
Schaeffer #238 Ultra Supreme Grease is built to hold its own under pressure—literally. Here's what operators can expect:
- Pressure resistance up to 500,000 psi, protecting components under extreme shock loads
- 100% reversibility—the grease retains its consistency even after intense mechanical action, so it doesn't break down and leave components exposed
- Excellent shear and mechanical stability, meaning the grease stays in place rather than separating or migrating off components
- High dropping point, so it remains effective at elevated temperatures without liquefying
- Increased oxidation stability, which extends the usable life of the grease itself
These aren't minor incremental gains. For equipment running long shifts in harsh conditions, each of these properties translates directly into fewer breakdowns and lower operating costs.
How Does Schaeffer #238 Perform in Wet or Moisture-Heavy Conditions?
Water contamination is one of the most common causes of bearing failure. Schaeffer #238 Ultra Supreme Grease resists emulsifying, washing out, and spraying off when exposed to moisture—keeping its protective film intact even when equipment operates in rain, mud, or high-humidity environments.
This makes it particularly well-suited for off-road machinery, marine-adjacent applications, and any equipment regularly exposed to water or steam.
Is Schaeffer #238 Right for Your Equipment?
Schaeffer #238 Ultra Supreme Grease is one of Schaeffer's tackiest formulations. That high tack is an asset in most heavy-duty applications—it helps the grease cling to components and resist throw-off under rotation.
However, that same property makes it unsuitable for two specific applications: passenger car automotive wheel bearings and electric motor bearings. For those, a lighter, less viscous grease is the better choice.
Choose Schaeffer #238 if: your equipment operates under heavy loads, high heat, significant shock, or frequent moisture exposure—and if extended lubrication intervals and reduced downtime matter to your operation.
Look elsewhere if: you're lubricating passenger car wheel bearings or electric motor bearings.
Make Every Lubrication Cycle Count
Schaeffer #238 Ultra Supreme Waterproof Grease delivers where conventional greases fall short—under pressure, in heat, and in wet conditions. Its PAO synthetic base, aluminum complex thickener, and moly fortification combine to create a grease that protects equipment longer, reduces wear, and cuts the cost of unplanned downtime.
For heavy-duty operations where reliability is non-negotiable, #238 is a practical upgrade worth making.
Frequently Asked Questions
What makes Schaeffer #238 different from conventional grease?
Schaeffer #238 uses PAO synthetic base oils and an aluminum complex thickener, which provide superior stability, moisture resistance, and heat tolerance compared to conventional petroleum-based greases.
What equipment is Schaeffer #238 best suited for?
Schaeffer #238 Ultra Supreme Grease is designed for heavy-duty automotive and off-road equipment—including construction machinery, agricultural equipment, and fleet vehicles operating under high loads or in wet conditions.
Can Schaeffer #238 be used in electric motor bearings?
No. Due to its high tack, Schaeffer #238 is not recommended for electric motor bearings or passenger car wheel bearings.
Does Schaeffer #238 meet OEM specifications?
Yes. Schaeffer #238 meets Caterpillar's 5% moly specification for grease.