Ford Explorer 1St Generation – The Essential Guide To Maintenance
The first-gen Ford Explorer is a legendary SUV that blends truck-like durability with daily-driver comfort. This guide provides the technical insights you need to maintain the 4.0L V6 engine, troubleshoot the TTB suspension, and prepare your rig for any adventure.
Finding a classic SUV that is as capable on the trail as it is on the highway can be a challenge. You likely agree that modern SUVs often feel more like tall cars than rugged workhorses.
I promise that by the end of this guide, you will understand exactly how to keep your ford explorer 1st generation running strong for years to come. We will cover everything from engine quirks to suspension geometry.
We are going to look at the legendary 4.0L Cologne V6, the unique Twin Traction Beam front end, and the most common failure points every owner should know. Let’s get your rig trail-ready.
History and Legacy of the ford explorer 1st generation
The automotive world changed in 1990 when Ford introduced the 1991 model year Explorer. It effectively replaced the Bronco II and took the market by storm.
While the Bronco II was narrow and prone to tipping, this new platform offered a wider stance. It shared many components with the Ford Ranger, making it a body-on-frame powerhouse.
The ford explorer 1st generation was available in both two-door and four-door configurations. The two-door Sport models featured a shorter wheelbase, making them favorites for tight off-road trails.
Under the hood, every model featured the 4.0L OHV V6 engine. This engine was not a speed demon, but it provided the low-end torque necessary for towing and climbing.
Ford utilized a Twin Traction Beam (TTB) front suspension on 4WD models. This design is a hybrid between a solid axle and a fully independent suspension.
It offered better high-speed handling than a solid axle while maintaining significant wheel travel. Many enthusiasts still prefer the TTB for its durability in desert racing and rock crawling.
Maintaining the 4.0L Cologne V6 Engine
The heart of this SUV is the 4.0L Cologne V6. This engine is known for being incredibly robust if you manage the cooling system properly.
One of the first things you should check is the lower intake manifold bolts. These have a tendency to loosen over time, leading to vacuum leaks or coolant consumption.
If you hear a whistling sound or notice a rough idle, inspect the intake gaskets. Replacing these gaskets is a great weekend project for a DIY mechanic with basic hand tools.
The ignition system is straightforward, utilizing a coil pack and standard spark plug wires. Always use Motorcraft double platinum plugs for the best performance and fuel economy.
Keep a close eye on the plastic radiator tanks. After thirty years, the plastic becomes brittle and can crack under pressure, leading to sudden overheating.
I recommend upgrading to a three-row aluminum radiator if you plan on towing. This provides a significant margin of safety during hot summer months or steep climbs.
Oil changes are simple on this engine. Use a high-quality 5W-30 conventional or synthetic blend oil to keep the overhead valves lubricated and quiet.
Solving Common Vacuum Leaks
Old rubber hoses are the enemy of a smooth-running V6. Inspect the vacuum lines near the fuel pressure regulator and the brake booster.
A cracked vacuum line can cause the transmission to shift harshly. The A4LD automatic transmission relies on a vacuum modulator to determine shift timing.
Replacing these lines with silicone hoses is an inexpensive way to improve engine response. Silicone resists heat better than the original rubber equipment.
Mastering the Twin Traction Beam Suspension
The TTB suspension is the defining feature of the 4WD ford explorer 1st generation. It consists of two large beams that cross over each other.
This setup provides excellent ground clearance because the differential moves with the arm. However, it is notorious for being difficult to align correctly.
When the front springs sag, the tops of the tires tilt inward. This is known as negative camber, and it will eat through your front tires quickly.
To fix this, you must install adjustable alignment cams in the upper ball joint housings. These allow an alignment shop to correct the caster and camber angles.
If you are lifting the vehicle, you must use drop brackets for the pivot points. Without these brackets, you will never achieve a proper alignment.
Check the pivot bushings where the beams attach to the frame. If these are cracked or missing, the front end will feel loose and “darty” on the highway.
Polyurethane bushings are a popular upgrade here. They offer a firmer feel and last much longer than standard rubber replacements.
Upgrading Radius Arm Bushings
The radius arms hold the axle beams in place front-to-back. The bushings at the rear of these arms are a very common failure point.
You will know they are bad if you hear a “clunk” under your feet when hitting a bump. Replacing them requires removing the large nut at the rear of the arm.
Always use a heat shield on the passenger side bushing. The exhaust pipe runs very close to it and can melt the rubber over time.
Troubleshooting the Drivetrain and Transmission
Most first-gen Explorers came with the A4LD four-speed automatic transmission. While decent for its time, it is sensitive to excessive heat.
If you plan on off-roading, install the largest external transmission cooler you can fit. Heat is the primary killer of the internal clutches and seals.
For those who prefer three pedals, the M5OD five-speed manual is a tough alternative. It is generally very reliable but has one specific weakness.
The rubber shift rail plugs at the back of the shift tower can dry out and leak. If the fluid gets too low, the transmission will burn out the internal bearings.
Check these plugs immediately and replace them with metal freeze plugs or new Viton rubber seals. It is a five-dollar fix that saves a thousand-dollar transmission.
The transfer case is usually the BorgWarner 1354. It is a stout unit, but the electric shift motor often fails due to lack of use.
If your 4WD light just flashes, the motor is likely stuck. You can often fix this by tapping it with a hammer or cleaning the internal contact plate.
Converting to Manual Locking Hubs
The factory automatic locking hubs were convenient but prone to failure at the worst possible moments. They rely on plastic components that shatter under stress.
I highly recommend swapping these for manual locking hubs. This requires a conversion kit that includes new spindle nuts and the hub assemblies.
Manual hubs are much stronger and give you the peace of mind that 4WD will actually engage. Just remember to get out and lock them before you hit the mud.
Essential Safety Checks for Older SUVs
Safety should always be your priority when working on a ford explorer 1st generation. Start with the braking system, specifically the rear drum brakes.
The self-adjusters often seize up, leaving the front discs to do all the work. This leads to increased stopping distances and warped front rotors.
Inspect the brake lines for rust, especially where they run along the frame rails. Steel lines can thin out over decades of exposure to road salt.
Check the fuel tank straps as well. These are known to rust through, which could cause the tank to sag or fall while driving.
If you are heading off-road, ensure your battery is tied down securely. A loose battery can short out against the hood, potentially causing a fire.
Always carry a fire extinguisher and a basic first-aid kit. When exploring remote areas, let someone know your planned route and expected return time.
Never work under a vehicle supported only by a floor jack. Always use high-quality jack stands rated for the weight of the SUV.
Off-Road Modifications and Trail Prep
The ford explorer 1st generation is an excellent platform for a budget off-roader. The rear axle is usually a Ford 8.8-inch unit, which is incredibly strong.
Look at your door sticker for the axle code. If you have code “D4,” you have a limited-slip differential with 3.73 gears, which is a great starting point.
A simple “shackle and spacer” lift can provide about two inches of clearance. This allows you to fit 31-inch all-terrain tires without major trimming.
For more serious wheeling, a 4-inch suspension lift is the sweet spot. This allows for 33-inch tires, which significantly improves ground clearance over rocks.
Consider adding rock sliders to protect the thin sheet metal of the rocker panels. The long wheelbase of the four-door model makes it vulnerable to “high-centering.”
If you find yourself stuck, always use rated recovery points. Never pull from the bumper or a suspension component, as these can fly off under tension.
If you are unsure about a technical obstacle, get out and scout the line. It is better to take a minute to look than to spend an hour winching.
Frequently Asked Questions About the Ford Explorer 1st Generation
What is the most common problem with the 1st gen Explorer?
The most frequent issues involve the A4LD automatic transmission and the radius arm bushings. Transmission overheating and front-end “clunking” are the two things every owner should watch for.
Can I fit 33-inch tires without a lift?
No, 33-inch tires will rub significantly on the fenders and the radius arms. You will need at least a 4-inch suspension lift or extensive fender trimming to clear 33s comfortably.
Is the 4.0L V6 engine reliable?
Yes, the 4.0L Cologne V6 is very reliable. It can easily last over 250,000 miles if the cooling system is maintained and the oil is changed regularly. It is a “non-interference” engine, meaning a broken timing chain won’t destroy the valves.
How do I know if my 4WD is working?
The easiest way is to find a loose surface like gravel. Engage 4WD and turn the wheel sharply while moving slowly. You should feel the steering “bind” or hop slightly, indicating the front wheels are receiving power.
Where can I find replacement parts?
Because it shares so many parts with the Ford Ranger, mechanical parts are widely available at local auto stores. Trim pieces and interior plastics are best found at salvage yards or online enthusiast forums.
Final Thoughts on Owning a Classic
Owning a ford explorer 1st generation is a rewarding experience for any DIY mechanic. These vehicles represent a time when trucks were simple, rugged, and easy to understand.
By staying on top of the cooling system and the suspension bushings, you can enjoy a very capable rig. Whether you are commuting or hitting the trails, this SUV delivers.
Take your time with repairs, use quality parts, and don’t be afraid to get your hands dirty. There is a massive community of owners ready to help if you hit a snag.
Keep your tools ready, stay safe on the trails, and enjoy the adventure. Happy wrenching!
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