Question 1

Worn Bearings and Low Oil Pressure

Accepted Answer

Oil pressure drops below 20 psi at idle when hot. Knocking noise from the bottom end, particularly under load. May also develop a deep rumble at idle. The Grey Motor uses plain bearings (babbit metal shells) for the mains and big ends. After 70+ years, even well-maintained engines have worn bearings. The oil pump is a gear-type unit that also wears over time, reducing oil flow. A bottom-end rebuild, new main bearings, big-end bearings, thrust washers, and an oil pump rebuild or replacement. The crank should be checked for wear and reground if necessary. Budget $1,500-2,500 at a machine shop experienced with these engines. The Grey Motor is simple to strip and reassemble, a skilled home mechanic can do this in a weekend with the engine out of the car.

Question 2

Valve Seat Recession

Accepted Answer

Gradual loss of compression, rough running, tapping noise from the engine that gets worse over time. May develop a misfire. The Grey Motor was designed to run on leaded petrol. The lead in the fuel provided a cushion between the valve face and the valve seat, preventing metal-to-metal contact. Modern unleaded fuel eliminates this cushion, and the soft cast-iron valve seats wear, the valves gradually recede into the head. The cylinder block needs to be machined to accept hardened valve seat inserts. This is a machine shop job, the block must be removed from the car. Budget $800-1,500 for a full valve seat insert job. Alternatively, use a lead replacement additive (Valvemaster or similar) in every tank of fuel. This is a Band-Aid solution but it slows the recession significantly and is adequate for cars that aren't driven daily.

Question 3

Overheating in Modern Traffic

Accepted Answer

Temperature gauge climbs or the engine boils over in slow traffic or on hot days. The Grey Motor's cooling system was designed for 1950s driving conditions, sustained speeds on open roads, not crawling through suburban traffic in 35-degree heat. The original radiator is marginal for modern conditions, the water pump capacity is modest, and the engine-driven fan only moves adequate air at highway speeds. Flush and check the radiator, a 70-year-old radiator is almost certainly partially clogged. Have it recored ($300-600) or fit a new aluminium replacement ($400-800). Add an electric thermo fan behind the radiator for low-speed cooling. Ensure the thermostat is functioning correctly (replace it, they're cheap). Check that the fan belt is tight and the water pump is not leaking.

Question 4

Fuel Pump Failure

Accepted Answer

Engine stalls, won't restart, or runs inconsistently. Fuel starvation symptoms, the engine dies under load but may restart after sitting for a few minutes. The mechanical fuel pump is driven off the camshaft and uses a rubber diaphragm that perishes with age and modern fuel blends. When the diaphragm fails, the pump can't draw fuel from the tank. Replace the fuel pump diaphragm (rebuild kits are available, $30-60) or replace the entire pump ($80-150). An aftermarket electric fuel pump mounted near the tank is a common upgrade, it provides more consistent fuel pressure and eliminates the mechanical pump as a failure point. If fitting an electric pump, add a fuel pressure regulator to avoid over-pressuring the carburettor.

Question 5

Carburettor Deterioration

Accepted Answer

Hard starting, rough idle, flat spots on acceleration, flooding (fuel running out of the carby), black smoke, poor fuel economy. The Stromberg carburettor's internal components, needle valve, float, accelerator pump diaphragm, gaskets, all deteriorate with age. Ethanol in modern fuel attacks old rubber seals. Jets can clog from fuel residue, particularly if the car sits for extended periods. Rebuild the carburettor with a rebuild kit ($50-100 if you can source one). These are simple single-barrel carburettors that can be stripped and rebuilt on a kitchen table. The challenge is sourcing genuine Stromberg rebuild kits, they're becoming scarce. Some owners convert to a Weber 32/36 DGAV, which is a bolt-on replacement that provides better throttle response and easier tuning. Budget $300-500 for a Weber conversion.

Question 6

Second Gear Synchro Wear

Accepted Answer

Grinding or crunching when shifting into second gear, particularly on quick downshifts. May also be reluctant to engage second. The synchromesh on second gear in the 3-speed manual wears faster than the other gears because it's the most-used ratio. After 70 years, even a lightly-used gearbox will have worn synchros. Gearbox rebuild with new synchro rings. Budget $800-1,500. Many owners learn to double-clutch on downshifts to extend synchro life, it's a skill worth developing. Some drivers simply accept the crunch and live with it.

Question 7

Column Shift Linkage Wear

Accepted Answer

Difficulty selecting gears from the column-mounted shifter. The lever feels vague, sloppy, or won't engage gears precisely. The column shift mechanism uses a series of rods and bushings that wear over time. The bushings develop slop, the rods bend from decades of use, and the detent springs weaken. Inspect and replace worn bushings and rods. A complete column shift rebuild kit may be available from specialists, but more commonly you'll need to source individual components. Budget $200-500 for a complete linkage restoration. Some owners convert to a floor-mounted shifter, this is a significant modification that requires a gear lever assembly and tunnel modification. It's not period-correct but is far more positive in operation.

Question 8

King Pin Wear

Accepted Answer

Vague steering, wandering on straight roads, uneven front tyre wear. Clunking over bumps from the front end. The FJ/FC front suspension uses king pins, vertical pins that the stub axle pivots on, rather than the ball joints used on later cars. King pins wear in their bushings, developing play that translates directly to steering vagueness. Australian roads accelerate this wear. Replace king pins and bushings. King pin kits are available from specialists ($200-400 per side). This is a moderately skilled job requiring a press to remove and install the pins. Have it done at a workshop if you're not equipped. While the front end is apart, replace the tie rod ends and any worn bushings.

Question 9

Sagging Leaf Springs

Accepted Answer

The rear of the car sits lower than it should. The car bottoms out over bumps. The rear end wallows and bounces excessively. Leaf springs lose their temper over decades. Cars that have been loaded heavily (carrying passengers, towing, loaded utes) sag faster. Broken individual leaves also reduce spring rate. Have the springs re-tempered (a spring specialist can heat and re-form them) or replace with new springs. New leaf spring sets are available from suspension specialists ($300-600 per pair). Re-tempering is cheaper ($100-200 per spring) but doesn't restore full original height if the springs are severely fatigued.

Question 10

Steering Box Wear

Accepted Answer

Excessive play in the steering wheel, you can turn the wheel significantly before the front wheels respond. Heavy or uneven steering effort. The recirculating ball steering box wears internally as the balls and tracks develop play. The sector shaft bushings also wear. This is universal on cars of this age. Adjust the steering box (there's an adjusting screw on top of the box that takes up some play). If adjustment can't eliminate the play, the box needs rebuilding or replacing. Rebuilt steering boxes are available on exchange ($400-700). A complete steering linkage refresh, steering box, idler arm, tie rod ends, drag link, is a worthwhile exercise ($800-1,500 all up).

Question 11

Leaking Wheel Cylinders

Accepted Answer

Brake pedal feels soft or sinks slowly. Reduced braking effectiveness. Brake fluid visible on the inside of the brake drums. The rubber seals inside the wheel cylinders harden and crack with age, allowing brake fluid to leak past the pistons. This is universal on old cars with drum brakes. Replace all four wheel cylinders. Do not replace only the leaking one, if one has failed, the others are close behind. Wheel cylinder kits or complete cylinders are available ($50-80 each). Flush the entire brake system with fresh DOT 3 fluid.

Question 12

Drum Brake Fade

Accepted Answer

Braking effectiveness decreases during sustained use, descending a hill, repeated stops in traffic. The pedal feels normal but the car doesn't slow down as effectively. Drum brakes trap heat. As the drums heat up, the coefficient of friction between the shoe lining and drum decreases. This is an inherent limitation of drum brakes, not a fault. The FJ/FC's relatively small drums exacerbate the issue. This is a characteristic of the braking system, not something that can be "fixed" without converting to disc brakes (which is not straightforward on these cars). Ensure the brakes are in the best possible condition, properly adjusted, with quality linings, and with the drums machined true. Use engine braking on descents. Plan your stops early. Drive with awareness that you don't have modern braking performance.

Question 13

Generator and Voltage Regulator Issues

Accepted Answer

Battery goes flat, dim headlights, ammeter shows discharge when the engine is running. The FJ and FC use a generator (not an alternator) and an external voltage regulator. Generators produce less output than alternators, particularly at low RPM. The voltage regulator's contact points wear and corrode, leading to overcharging or undercharging. Clean and adjust the voltage regulator contacts, or replace the regulator ($60-120). If the generator is worn (brush wear, commutator damage), have it reconditioned or convert to an alternator. An alternator conversion ($200-400 including bracket modification) is a common and worthwhile upgrade, it provides significantly more charging capacity, particularly for cars with added accessories like electric fans or modern audio systems.

Question 14

Corroded Wiring

Accepted Answer

Intermittent electrical faults, lights flickering, instruments dropping out, horn not working, starter motor intermittent. The cloth-insulated wiring used in the 1950s deteriorates over seven decades. The insulation becomes brittle and crumbles, causing short circuits and open circuits. Connector terminals corrode. Earth straps develop high resistance. For isolated faults, trace and repair individual circuits. For cars with widespread wiring issues, a complete rewire is the best solution. Reproduction wiring looms are available from specialists ($400-800 for a complete loom). A rewire is time-consuming but not technically difficult, these cars have very simple electrical systems with fewer than 20 circuits.

Question 15

Floor Pan Rust

Accepted Answer

Visible rust perforation on the underside of the floor. Soft or spongy metal when prodded. In severe cases, you can see daylight through the floor from inside the car. Water enters the cabin through deteriorated door seals, windscreen seals, and the firewall. It sits on the floor pans, which have no drainage. Road spray attacks the underside. Seventy years of moisture exposure is relentless. Minor surface rust: treat with rust converter, seal, and undercoat. Perforated floor pans: cut out the rust and weld in new metal. Reproduction floor pan sections are available from specialists. A full floor pan replacement on a rotisserie is a major restoration job, budget $3,000-8,000 for both sides.

Question 16

Lower Guard (Fender) Rot

Accepted Answer

Bubbling paint, visible rust, perforation along the lower edges of the front and rear guards. The lower guards trap road spray between the inner and outer skins. Mud and moisture sit against the metal and cause rust from the inside out. The guards' curved shape makes drainage poor. Reproduction outer guard sections are available for the FJ and FC. A skilled panel beater can cut out the rotted section and weld in new metal. Budget $500-1,500 per guard for a proper repair. Do not bog over guard rust, it always comes back.

Question 17

Windscreen Seal Deterioration

Accepted Answer

Water leaks into the cabin during rain. Rust develops under the windscreen rubber and around the windscreen frame. The rubber windscreen seal hardens, cracks, and shrinks over time. Water gets between the seal and the body, sits against the metal, and causes rust that's invisible until the windscreen is removed. Remove the windscreen, clean out all rust, treat with rust converter, prime, and seal. Fit a new windscreen seal ($80-150 from specialists). If the windscreen frame is perforated, it needs welding repair before the new seal goes in. Budget $300-800 for a complete windscreen reseal with rust treatment.

FJ / FE / FC

FJ / FE / FC known problems