S & F TRANSMISSION OILS & F TRANS OIL was formulated to provide the proper viscosity.


S & F TRANSMISSION OIL is an SAE 90 gear oil equal to the SAE 50 motor oil classification. Proper viscosity is required for film strength and proper flow to the various transmission components.


Royal Oil Co.’s starting point for this product is the crude oil.
It has to be of low sulphur or sweet type paraffin-based midcontinent quality. Then the base oils are put through a solvent extraction process which removes undesirable characteristics that might lead to sludge, gum, or varnish under heat. The oils then go through another step called hydro-treating which improves the oxidation characteristics of the oil and improves the oil’s response to the high quality additives used by Royal Oil Co. The oils also go through a de-waxing process to make them suitable for cold temperatures. The finest paraffin base stocks with a 95 viscosity index are used because they are less susceptible to attack from oxygen and various acids. They allow for greater thermal oxidation stability and can be used over a wide temperature range.


S & F TRANS OIL contains anti-wear additives which provide a protective film on all moving parts.
In operation, transmissions have many heavily-loaded parts such as gear teeth and bearings. A protective film must be provided to prevent metal-to-metal contact between these parts and therefore prevent scoring, scuffing, and seizure. If the protection is not provided, expensive repair and downtime are the end results.


Transmissions generate heat when in operation — especially under heavily-loaded conditions.
Heat must be kept minimal for proper operation. S & F TRANSMISSION OIL acts as a coolant to dissipate heat so maximum efficiency may be maintained. It is formulated to remain stable under extreme conditions.


S & F TRANS OIL resists oxidation two ways.
Second, oxidation inhibitors are added to provide greater stability at elevated temperatures and prevent corrosion and sludge from forming. No foreign materials such as sediment or water are present.


Many transmission lubricants on the market may begin to foam during operation, causing extensive problems.
If foam is present, the level of gear oil drops and proper lubrication is not achieved. Remember, foam is mostly air; therefore, if foam is excessive, the oil film is lost resulting in metal-to-metal contact and wear. The metal-to-metal contact also increases heat and the foam helps trap the heat. This causes much higher than normal operating temperatures. The higher operating temperature helps to oxidize the lubricant which can lead to sludge and gum deposits. Fortunately, all this can be avoided by using S & F TRANS OIL because it contains excellent foam inhibitors to resist this serious problem.

Need More Info?

Download the S & F Transmission Oil Spec. Sheet, or Contact Us.