Maintaining the 1985 Toyota 4-RUNNER with its 2.4L 4-cylinder engine (specifically the engine code R-22REC L) requires fluids that are formulated to protect aging components while delivering performance. The original equipment specifications were designed for conventional mineral oils and fluids of that era, but modern fully synthetic lubricants offer superior protection against wear, sludge, and thermal breakdown. Switching to high-performance synthetic options ensures that your vehicle’s engine, transmission, and drivetrain remain robust, whether you are driving on paved highways or tackling rugged off-road terrain. Proper lubrication is the single most effective way to extend the operational life of this classic four-wheel-drive vehicle.
Recommended AMSOIL Products
- AMSOIL Signature Series 10W-30 100% Synthetic Motor Oil – The ultimate choice for your engine, offering up to 25,000 miles of protection and superior defense against horsepower loss and wear in high-stress conditions.
- AMSOIL Extended-Life 10W-30 100% Synthetic Motor Oil – Provides up to 20,000 miles of protection with enhanced cleaning power to keep the engine running smoother and help remove deposits that can accumulate over time.
- AMSOIL OE 10W-30 100% Synthetic Motor Oil – A cost-effective synthetic option that fights sludge and deposits, offering performance that exceeds conventional oils and meets OEM requirements.
- AMSOIL 10W-30 100% Synthetic High-Mileage Motor Oil – Specifically engineered for vehicles with over 75,000 miles, featuring a boosted detergent package to clean engines and reduced sludge to extend engine life.
- AMSOIL Oil Filter – Designed with greater capacity for small, wear-causing contaminants and 99% filtering efficiency at 20 microns to ensure clean oil circulates through critical engine parts.
- WIX Oil Filter – A premium alternative offering improvements over original equipment manufacturer-branded filters for reliable engine filtration.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Built to withstand heavy towing and elevated temperatures, ensuring smooth, shudder-free shifts and protection for the A340H transmission.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Guards against leaks and promotes smooth shifts while resisting harmful sludge for long-term transmission health.
- AMSOIL 75W-90 Manual Transmission & Transaxle Gear Lube – An excellent choice for manual gearboxes like the G52 and W56, offering outstanding cold-flow properties and protection for brass synchronizers.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – Provides advanced protection against wear and thermal runaway for front, rear, and transfer case differentials, ideal for limited-slip applications.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Designed for heavier loads and high-pressure environments, controlling operating temperatures and extending seal and equipment life.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – A versatile gear lube that controls thermal runaway and protects against rust and corrosion in front and rear differentials.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Ensures excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range for safer braking performance.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A ready-to-use 50/50 pre-mix formulation that protects all cooling system metals, gaskets, and hoses for up to 150,000 miles or 5 years.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option that greatly surpasses standards for metallic corrosion and erosion, requiring mixing with distilled water for ultimate protection.
- AMSOIL P.i.® Performance Improver Gasoline Additive – Restores up to 14% horsepower and GDI fuel injectors to 100% flow rate while improving fuel economy and preventing carbon buildup.
The 2.4L engine in your 1985 4-RUNNER is a robust inline-four that demands precise lubrication to handle the rigors of four-wheel driving. The engine oil capacity is approximately 4.9 quarts, including a filter change. When servicing the engine, it is critical to torque the oil drain plug to between 26 and 32 ft/lbs to prevent leaks while ensuring a secure seal. The cooling system requires a significant volume of coolant, holding about 9 quarts. Using a proper 50/50 antifreeze mixture ensures the engine does not freeze in winter or overheat during summer drives, which is vital for this older cast-iron block.
Transmission maintenance is equally critical for the longevity of this vehicle. For the 4-speed automatic transmission (A340H), the total fill capacity is 10.9 quarts, though an initial fill may require around 4.8 quarts. Synthetic automatic transmission fluids are superior for this application, as they remain fluid in sub-zero temperatures and prevent the sludge buildup that can cause shuddering or hard shifting in older units. If your 4-RUNNER is equipped with a manual transmission, such as the G52 or W56 five-speed models, a GL-4 or GL-5 gear lube is required. The capacity for these manual transmissions varies but is typically around 6.3 to 8.2 pints depending on the specific gear configuration.
The drivetrain also includes front and rear differentials and a transfer case, all of which benefit from high-quality synthetic gear lubricants. The front differential holds about 4.9 pints, while the rear differential holds approximately 4.6 pints. The transfer case generally requires 3.4 pints. Using a synthetic gear lube like the SEVERE GEAR® series provides better shear stability and extreme pressure protection than conventional mineral oils. This is particularly important for the 4-RUNNER, which was designed for off-road use and sees significant stress in its transfer case and axle gears when traversing rough terrain. Synthetic gear lubes also contain friction modifiers that are beneficial for limited-slip differentials.
Brake fluid is another often-overlooked component that ensures safety. The 1985 model utilizes a hydraulic brake system compatible with DOT 3 and DOT 4 fluids. AMSOIL’s synthetic brake fluid offers a much higher boiling point than standard fluid, which prevents vapor lock during heavy braking or when towing, ensuring consistent pedal feel and stopping power. Finally, for owners who store their vehicles seasonally or want to maximize fuel efficiency and engine cleanliness, AMSOIL P.i.® Performance Improver is a recommended fuel additive that restores lost horsepower and cleans injectors, helping the engine run as intended regardless of its age.
About the Vehicle
The 1985 Toyota 4-RUNNER holds a significant place in automotive history as the vehicle that transitioned the concept of a rugged off-roader into a reliable daily driver. Introduced in the mid-1980s, the 4-RUNNER was built on the same robust platform as the Toyota Hilux pickup truck, sharing many of its mechanical components. This particular model, equipped with the 2.4L 4-cylinder engine (code R-22REC L), was known for its durability and reliability rather than raw speed. The engine provided sufficient torque to tackle challenging trails while maintaining respectable fuel economy for its time, making it a favorite among outdoor enthusiasts and families alike.
What set the 4-RUNNER apart was its versatility. Unlike larger trucks that were difficult to park and maneuver, the 4-RUNNER offered a more car-like driving experience without sacrificing off-road capability. It featured a sturdy frame, independent front suspension, and a part-time four-wheel-drive system that allowed drivers to switch between two-wheel and four-wheel drive on the fly. This combination of comfort and utility helped establish Toyota as a leader in the SUV market, proving that you could have a capable off-road vehicle that was also practical for daily commuting.
Owners of this era of 4-RUNNER appreciate its straightforward mechanical design and the availability of parts, which has kept these vehicles running on the road and trail for decades. The 4-cylinder engine, while not the most powerful, is renowned for its longevity and simplicity, often outlasting more complex V6 or V8 engines with less maintenance. Today, the 1985 4-RUNNER is celebrated as a classic, symbolizing the golden age of Toyota’s off-road engineering. Its reputation for reliability means that with proper care and high-quality lubricants, these vehicles continue to perform well, serving as a testament to Japanese engineering quality of the 1980s.