The 2021 Jeep Gladiator belongs to the JT generation (pre-refresh) (2020-2023), built with 3.6L Pentastar V6, or 3.0L EcoDiesel V6 (2021-2023 only, automatic-only). It takes 0W-20 full synthetic on the Pentastar, 5W-40 full synthetic on the EcoDiesel. Oil changes run 10,000 miles (3.6L) / 8,000 miles (3.0L EcoDiesel). This is an early year of that generation, which usually means a handful of running changes were still being made.
A 2021 Jeep Gladiator is 5 years old in 2026, which at an average 12,000 miles a year puts it around 60,000 miles - the interval that decides its future. At roughly 60,000 miles the bigger fluids come due - transmission, differential, coolant - and this is the window that separates vehicles that reach 200,000 miles from those that do not. Deferring here is what produces expensive failures later. On that mileage estimate it should already have had transmission or CVT fluid, differential fluid and brake fluid at 60,000 miles, and the next milestone is 90,000 miles - a second transmission service, suspension inspection and belts - roughly 2.5 years away at average use.
The fault most worth knowing about on this generation is EcoDiesel high-pressure fuel pump failures reported 2021-2023. Owners also report Death wobble, a steering oscillation traced to worn track bar and steering components, most complaints logged in 2020; and Manual-transmission clutch pressure plate overheating/fracture (fire risk) - recalled 2020, expanded 2021 and again in 2023. None of these are certainties on any individual vehicle - they are the patterns worth checking for when you buy or when a symptom appears.
Track your 2021 Jeep Gladiator service history free with the ServiceSage maintenance tracker, or compare it against other model years on the Jeep Gladiator maintenance schedule hub.
| Interval | Service |
|---|---|
| Every 4,000 mi (severe duty / off-road) | Engine oil & filter change, Rotate tires, Inspect axle vents, skid plates, and undercarriage, Inspect for off-road damage |
| Every 8,000 mi / 12 months (3.0L EcoDiesel) | Engine oil & filter change (5W-40 full synthetic), Replace fuel filter (every other oil change, roughly 16,000 mi), Inspect DEF system and top off as needed |
| Every 10,000 mi / 12 months | Engine oil & filter change (0W-20 3.6L Pentastar), Rotate tires, Inspect brakes, steering, and suspension, Inspect ball joints and track bar |
| Every 20,000 mi | Replace cabin air filter, Inspect brake pads and rotors, Inspect CV joints and driveshafts |
| Every 30,000 mi | Replace engine air filter, Inspect drive belt, Inspect coolant condition and hoses |
| Every 36 months (brake fluid) | Replace brake fluid (DOT 3) |
| Every 60,000 mi | Front and rear axle (differential) fluid change (Dana 44 AdvanTEK), Transfer case fluid change (ATF+4 or BW44-44), Automatic transmission fluid service (severe duty), Manual transmission fluid change (if equipped) |
| Every 100,000 mi | Replace spark plugs (3.6L Pentastar, 6 plugs), Inspect PCV valve, Inspect water pump |
| Every 120,000 mi | Automatic transmission fluid & filter (normal duty), Inspect valvetrain |
| Every 150,000 mi | Engine coolant flush (Mopar OAT / HOAT), Inspect entire cooling system |
The table above is indexed by service interval. This is the same schedule indexed by odometer reading, for when you know your mileage and want the list. If your odometer sits between these figures, work back to the last one you passed and catch up anything skipped.
| Odometer | Service due |
|---|---|
| 30,000 mi (48,000 km) | Engine oil & filter change (0W-20 3.6L Pentastar), Rotate tires, Inspect brakes, steering, and suspension, Inspect ball joints and track bar, Replace engine air filter, Inspect drive belt, Inspect coolant condition and hoses. The every-8,000 mi service runs on its own cycle - the nearest fall at 24,000 and 32,000 miles. |
| 60,000 mi (97,000 km) | Engine oil & filter change (0W-20 3.6L Pentastar), Rotate tires, Inspect brakes, steering, and suspension, Inspect ball joints and track bar, Replace cabin air filter, Inspect brake pads and rotors, Inspect CV joints and driveshafts, Replace engine air filter, Inspect drive belt, Inspect coolant condition and hoses, Front and rear axle (differential) fluid change (Dana 44 AdvanTEK), Transfer case fluid change (ATF+4 or BW44-44), Automatic transmission fluid service (severe duty), Manual transmission fluid change (if equipped). The every-8,000 mi service runs on its own cycle - the nearest fall at 56,000 and 64,000 miles. |
| 90,000 mi (145,000 km) | Same as the 30,000 mi service. The every-8,000 mi service runs on its own cycle - the nearest fall at 88,000 and 96,000 miles. |
| 100,000 mi (161,000 km) | Engine oil & filter change (0W-20 3.6L Pentastar), Rotate tires, Inspect brakes, steering, and suspension, Inspect ball joints and track bar, Replace cabin air filter, Inspect brake pads and rotors, Inspect CV joints and driveshafts, Replace spark plugs (3.6L Pentastar, 6 plugs), Inspect PCV valve, Inspect water pump. The every-8,000 mi service runs on its own cycle - the nearest fall at 96,000 and 104,000 miles. |
| 120,000 mi (193,000 km) | Engine oil & filter change (5W-40 full synthetic), Replace fuel filter (every other oil change, roughly 16,000 mi), Inspect DEF system and top off as needed, Engine oil & filter change (0W-20 3.6L Pentastar), Rotate tires, Inspect brakes, steering, and suspension, Inspect ball joints and track bar, Replace cabin air filter, Inspect brake pads and rotors, Inspect CV joints and driveshafts, Replace engine air filter, Inspect drive belt, Inspect coolant condition and hoses, Front and rear axle (differential) fluid change (Dana 44 AdvanTEK), Transfer case fluid change (ATF+4 or BW44-44), Automatic transmission fluid service (severe duty), Manual transmission fluid change (if equipped), Automatic transmission fluid & filter (normal duty), Inspect valvetrain. |
| 150,000 mi (241,000 km) | Engine oil & filter change (0W-20 3.6L Pentastar), Rotate tires, Inspect brakes, steering, and suspension, Inspect ball joints and track bar, Replace engine air filter, Inspect drive belt, Inspect coolant condition and hoses, Engine coolant flush (Mopar OAT / HOAT), Inspect entire cooling system. The every-8,000 mi service runs on its own cycle - the nearest fall at 144,000 and 152,000 miles. |
| 200,000 mi (322,000 km) | Engine oil & filter change (5W-40 full synthetic), Replace fuel filter (every other oil change, roughly 16,000 mi), Inspect DEF system and top off as needed, Engine oil & filter change (0W-20 3.6L Pentastar), Rotate tires, Inspect brakes, steering, and suspension, Inspect ball joints and track bar, Replace cabin air filter, Inspect brake pads and rotors, Inspect CV joints and driveshafts, Replace spark plugs (3.6L Pentastar, 6 plugs), Inspect PCV valve, Inspect water pump. |
| Fastener | Torque | Size |
|---|---|---|
| Lug nut | 130 ft-lbs (176 Nm) | 21mm |
Maintenance keeps these away, but when the dash does light up these are the codes this vehicle throws most often - each with what it means and what the repair actually costs.