Keeping your 1987 Ford Bronco running strong requires more than just basic maintenance; it demands the right fluids to handle the unique demands of its 4.9L inline-six engine and rugged drivetrain. Whether you are navigating city streets or tackling off-road trails, synthetic lubricants provide superior protection against wear, extreme temperatures, and contamination. Proper fluid selection ensures optimal performance, extends the life of critical components, and maintains the vehicle’s legendary capability. This guide details the specific AMSOIL products and capacities needed to keep your Bronco in peak condition.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Delivers unsurpassed protection with a capacity of 6.0 quarts for the 4.9L engine, offering up to 25,000 miles of performance.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Provides 37% more cleaning power for smoother operation, ideal for extended intervals up to 20,000 miles.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – A cost-effective choice that fights sludge and deposits, maintaining performance comparable to conventional oils.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Specifically formulated for engines over 75,000 miles with boosted detergents to reduce sludge.
- AMSOIL Oil Filter – Ensures 99% efficiency at 20 microns to reduce engine wear and allow for extended oil change intervals.
- WIX Oil Filter – A premium alternative offering improved media over standard OEM filters for consistent flow and filtration.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – An OAT formulation providing up to 150,000 miles of protection for the cooling system.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option requiring mixing, offering extended service life for heavy-duty applications.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Withstands towing, elevated temperatures, and challenging terrain with reserve protection.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Guards against leaks and promotes smooth, shudder-free shifts in your Ford transmission.
- AMSOIL Torque-Drive® 100% Synthetic Automatic Transmission Fluid – Fights thermal and oxidative degradation to provide long oil life in automatic transmissions.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Ensures excellent ABS responsiveness and stable viscosity across a wide temperature range.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Controls thermal runaway and protects gears against wear and corrosion.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – Offers advanced protection for all ambient temperatures with reduced operating temperatures.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Provides long oil and seal life with friction modifiers for limited-slip differentials.
- AMSOIL Super Shift® Racing Transmission Fluid – Resists extreme heat to virtually eliminate slippage, ideal for power steering and performance applications.
Engine Oil and Filtration
The heart of your 1987 Ford Bronco is the 4.9L inline-six engine. While robust, this engine benefits significantly from the high shear stability and thermal resistance of synthetic motor oils. AMSOIL recommends a 5W-30 viscosity for all temperature ranges. The oil capacity, when changing the filter, is 6.0 quarts. It is important to follow proper refilling procedures: remove the dipstick to allow for adequate venting so the oil can flow smoothly into the crankcase. After refilling, check the oil level to ensure it is correct. The oil drain plug should be torqued to 15-25 ft/lbs.
For the best protection, AMSOIL Signature Series 5W-30 offers 75% more engine protection against horsepower loss and wear, guaranteeing up to 25,000 miles or one year of service. If you prefer extended intervals but slightly less than the Signature Series, the AMSOIL Extended-Life 5W-30 provides 37% more cleaning power to keep the engine running smoother and lasts up to 20,000 miles. For those seeking a value option that still outperforms conventional oils, the AMSOIL OE 5W-30 fights sludge and deposits effectively. If your Bronco has accumulated over 75,000 miles, the AMSOIL 5W-30 High-Mileage Motor Oil features unique chemistry with boosted detergents and enhanced anti-wear additives to help older engines perform better.
Filtration is just as critical as the oil itself. The AMSOIL Oil Filter provides 99% efficiency at 20 microns, offering greater capacity for wear-causing contaminants than competing filters. This allows for lower restriction, keeping engine parts properly lubricated throughout the extended service intervals. Alternatively, the WIX Oil Filter offers premium media that improves upon the original equipment manufacturer filters, ensuring consistent flow and contaminant removal.
Transmission and Drivetrain
The 1987 Bronco often came equipped with the AOD automatic transmission, which can benefit greatly from a synthetic fluid. The AOD fluid capacity varies by fill type: the initial fill is 3 quarts, while a total fill (with the torque converter) reaches 12.3 quarts. The transmission fluid specification has been updated from Mercon to Mercon V per TSB 06-14-4, so ensuring the fluid meets this standard is vital.
The AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid is designed to withstand the rigors of heavy towing, elevated temperatures, and challenging terrain. It remains fluid in sub-zero temperatures and provides reserve protection during heavy use. For a more budget-friendly option that still protects against wear and sludge while promoting smooth, shudder-free shifts, the AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid is an excellent choice. The AMSOIL Torque-Drive 100% Synthetic Automatic Transmission Fluid is another robust option that specifically fights thermal and oxidative degradation to provide a long oil life.
For manual transmissions, the source data indicates no specific recommendations are available in the current database, but owners should consult the vehicle manual for specific viscosity requirements. Similarly, transmission filters are not specified in the current guidelines, so owners should ensure existing filters are inspected and replaced according to standard maintenance schedules.
The Bronco’s transfer case, often a Warner 1356, requires specific lubrication. The capacity for the Warner 1356 is 4 pints. The specification has been updated from Motorcraft XL-12 to Mercon LV. For the transfer case, the AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid or the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid can be utilized as a versatile fluid for these transfer cases, meeting the necessary specifications.
The differentials in the Bronco vary by model, but most common Dana axles (such as the Dana 44, 50, 60, 61, and 70) require GL-5 lubricants. For the front Dana 44, the capacity is 3.6 pints, while the front Dana 50 holds 3.8 pints, and the front Dana 60 holds 5.9 pints. Rear differentials vary, with the Dana 60/61 holding 5.9 pints, the Dana 70 HD taking 7.4 pints, and the Dana 70-2U holding 6.6 pints. Limited slip differentials also require compatible lubricants. AMSOIL SEVERE GEAR® 80W-90 is an advanced synthetic gear lube that controls thermal runaway and protects against rust and corrosion, making it ideal for all Dana axles. The AMSOIL SEVERE GEAR® 75W-90 and 75W-110 versions offer similar protection with specific viscosity characteristics, including friction modifiers for limited-slip applications, ensuring long oil, seal, and equipment life.
Coolant, Brakes, and Other Fluids
Proper cooling system maintenance is essential for the longevity of the 4.9L engine. The coolant capacity varies slightly by configuration, with one version requiring 13.3 quarts and another 13.7 quarts. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a unique poly-organic acid (OAT) formulation that protects all cooling system metals, gaskets, and hoses. It is phosphate-, nitrate-, nitrite-, silicate-, borate-, and amine-free, making it compatible with all other antifreeze colors. For those who prefer a concentrated product, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers up to 150,000 miles of protection in passenger cars and light trucks.
Brake safety is paramount. The 1987 Bronco uses a hydraulic brake fluid system meeting Ford specification WSS-M6C92-A. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid provides excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range, ensuring reliable stopping power in all conditions.
For power steering systems, the vehicle requires a fluid compatible with Type-F specifications. The AMSOIL Super Shift® Racing Transmission Fluid is recommended here, as it resists extreme heat to virtually eliminate slippage and improve shift performance. While designed for racing transmissions, its high thermal stability makes it an excellent choice for power steering applications where heat buildup can degrade fluid.
Seasonal storage and general maintenance are supported by a range of additional products. The AMSOIL Gasoline Stabilizer keeps fuel fresh for up to 12 months, protecting against varnish and gum buildup. For long-term storage, the AMSOIL Engine Fogging Oil prevents internal rust on engine components. Fuel system care is addressed with the AMSOIL P.i.® Performance Improver Gasoline Additive, which restores fuel injectors to 100% flow rate and improves fuel economy. The AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor lubricates the fuel system and upper cylinders, while the AMSOIL Power Foam® Carburetor and Induction-System Cleaner removes deposits from ethanol and degraded fuel to maximize horsepower.
For general vehicle care, the AMSOIL Synthetic Multi-Purpose Grease resists thermal and oxidation degradation for long-term performance. The AMSOIL Heavy-Duty Metal Protector leaves a wax-like coating that protects against salt, moisture, and corrosion. For rust removal and freezing component loosening, the AMSOIL MP Metal Protector is highly effective. Cleaning and detailing needs are met by the AMSOIL Silicone Spray, AMSOIL Heavy-Duty Degreaser, AMSOIL Brake and Parts Cleaner, and the AMSOIL Mudslinger® Mud and Dirt Repellent. The line is completed by the AMSOIL Engine Degreaser, AMSOIL Glass Cleaner, AMSOIL High-Foam Car Shampoo, AMSOIL Exterior Ceramic Spray, and interior detailers.
About the 1987 Ford Bronco
The 1987 Ford Bronco represents a pivotal era in the history of American four-wheel-drive vehicles. Produced during the transition from the square-bodied design to the new generation that would arrive in 1988, the 1987 model stands as a classic example of 1980s rugged utility. This specific iteration, equipped with the inline-six 4.9L engine (also known as the “Long Block”), is beloved by enthusiasts for its simplicity and torque. The 4.9L engine produces ample low-end power suitable for both heavy-duty work and off-road crawling, distinguishing it from the V8 options available in the lineup. While V8s offered higher top-end horsepower, the 4.9L was praised for its reliability and ease of maintenance, making it a favorite for those who spend significant time on the trail where fuel economy and mechanical dependability are key.
Standing on the shoulders of the previous generation, the 1987 Bronco maintained the iconic boxy shape that defined the brand through the 1970s. It was a vehicle designed for the American outdoors, capable of traversing rough terrain while offering a comfortable ride for daily commutes or family trips. The platform was known for its solid axle suspension, which provided excellent articulation and durability. Owners often modify these vehicles, but the stock configuration remains a robust base. The Bronco’s reputation is built on its ability to handle demanding conditions without the complexity found in later unibody competitors. It was a vehicle that commanded respect on and off the road.
Despite its reputation for durability, the 1987 Ford Bronco does face common issues that owners should address with high-quality lubricants. First, the 4.9L engine can suffer from oil consumption and sludge buildup over time, particularly if conventional oils are used for extended periods. Switching to AMSOIL synthetic motor oils can significantly reduce sludge by up to 67% in older engines and provide superior wear protection against horsepower loss. Second, the automatic transmission (AOD) used in many of these models is prone to overheating and shudder during heavy towing or off-roading. Synthetic transmission fluids offer better thermal stability, reducing the risk of transmission failure under stress. Third, the transfer case and differentials in these older 4x4s are susceptible to wear and tear from dirt and water ingress. Using synthetic gear lubes like AMSOIL SEVERE GEAR® helps seal against contamination and reduces operating temperatures, extending the life of the gears. Finally, rust and corrosion are persistent challenges for vintage 4x4s. Regular application of metal protectants and the use of high-quality brake fluids that resist water absorption can mitigate these effects, keeping the vehicle’s structural and safety components in better condition for years to come.
Ultimately, maintaining a 1987 Ford Bronco requires a commitment to quality. By selecting the right AMSOIL products, owners can ensure their vehicle continues to perform like the legend it is, overcoming the challenges of age and use with superior protection.