| Engine oil & filter | 3.6: 5 qt SAE 0W-20 meeting MS-6395 · 2.0T: 5 qt full-synthetic SAE 5W-30, API SN PLUS (Mopar MS-13340) | Then per the oil-life monitor confirm in manual | The JL Pentastar takes a quart less, and a thinner grade, than the JK's: Quadratec specifies the Mopar MO-349 (68191349AA) cartridge, the 24 mm cap torqued to 18 ft-lb and the 13 mm drain plug to 20 ft-lb. The owner's-manual sheet warns that non-SN PLUS oil in the 2.0T 'can cause engine damage not covered by the vehicle warranty.'Mopar 68507598AA engine oil filter, 2020–2022 JL · Quadratec ↗Mopar 4892339AB engine oil filter, 2018–2020 JL 2.0L · Quadratec ↗JL oils and fluids · ExtremeTerrain ↗ |
| Engine air filter | Panel filter | Way of Life's index of the factory schedule lists it at 30,000 mi; sooner on dusty trails | Check the airbox seal after any off-road trip in fine dust.Mopar 68257030AA air filter, 2018–2021 JL · Quadratec ↗Crown engine air filter, JL/JT · Quadratec ↗ |
| Cabin air filter | Behind the glovebox | Every 20,000 mi in the factory schedule (Way of Life index) | Diesel trucks use a different part.Mopar 68535621AA cabin air filter, 2018–2025 JL · Quadratec ↗ |
| Spark plugs | 3.6: Mopar SP225755AA (2018–20) · 2.0T: Mopar 68292346AA · gaps per the 2020 manual sheet: 3.6 0.043 in, 2.0T 0.024–0.025 in | 3.6 at 100,000 mi; 2.0T every 30,000 mi (Way of Life index of the factory schedule) | The 2.0T's 30,000-mile plug interval is easy to miss on a used truck, so ask for receipts.Mopar SP225755AA spark plug, 2018–2020 JL 3.6 · Quadratec ↗Mopar 68292346AA spark plug, 2018–2024 JL 2.0L · Quadratec ↗ |
| Coolant (engine, intercooler, eTorque/battery loops) | Mopar 10-year/150,000-mile OAT (MS.90032) · 3.6 engine: 11.2 qt (10.6 L), plus 1.9 qt motor-generator and 2.5 qt battery loops on eTorque trucks · 2.0T engine: 10.3 qt (9.7 L), plus a 3.2–3.5 qt intercooler loop | Flush at 10 years or 150,000 mi (factory schedule per Way of Life) | The 2.0T and eTorque trucks have more than one cooling loop, and the owner's-manual sheet lists separate capacities for the intercooler, the motor-generator unit and the battery. Bleed each one correctly.Mopar 68163849AB pre-diluted OAT coolant · Quadratec ↗Mopar 04893941AB water pump, 2018–2020 JL 3.6 with belt-start system · Quadratec ↗ |
| 8-speed automatic (850RE / ZF 8HP) | Mopar ZF 8&9 Speed ATF · about 9 L total (8HP50 figure on the owner's-manual sheet) | KBB's schedule lists transmission fluids at 100,000 mi | This is not ATF+4. The level is set hot at the fill plug, so it's a shop job for most owners. Mopar also sells a JL transmission filter.Mopar 68218925AB ZF 8&9-speed ATF · Quadratec ↗Crown 68417054AB automatic transmission filter, 2018–2024 JL · Quadratec ↗ |
| 6-speed manual | Mopar ATF+4 · 2.25 L | Every 30,000 mi under severe use (factory schedule per Way of Life) | Before you buy a manual truck, check that the clutch recall has been done.JL oils and fluids · ExtremeTerrain ↗ |
| Transfer case (Command-Trac / Rock-Trac / Selec-Trac) | Mopar ATF+4 · ≈1.6 L part-time cases, ≈1.76 L full-time Selec-Trac | Inspect at 30,000 mi; replace at 60,000 mi under severe use or 150,000 mi normally (Way of Life index) | If you use low range on the trail, treat the severe-service interval as normal.JL oils and fluids · ExtremeTerrain ↗ |
| Front axle | GL-5 75W-85 (later manuals; the 2018 manual listed 80W-90) · M186/Dana 30: 0.86 L · M210/Dana 44: 1.03 L | Every 40,000 mi under severe use (Way of Life index); after any deep water crossing | JL front axles take very little oil, so a slightly low level matters.75W-85 gear oil (search) · Quadratec ↗ |
| Rear axle | M220/Dana 44: GL-5 75W-85, 1.45 L (1.36 L with Trac-Lok) · M200/'Dana 35': 1.15 L of synthetic 75W-140 per the 2020 owner's-manual sheet · Trac-Lok axles need 70 ml (2.37 oz) of Mopar limited-slip additive | Every 40,000 mi under severe use (Way of Life index) | Check which rear axle you have before buying oil (see the axle FAQ). Synthetic 75W-140 is the usual towing upgrade.75W-85 gear oil (search) · Quadratec ↗Currie CE-9013S 75W-140 gear oil · Quadratec ↗ |
| Power steering fluid | Mopar electric steering pump fluid (2020 owner's-manual sheet) | Check the level at every oil change | JLWranglerForums members warn against topping up with ATF+4, even though some charts list it. Check for the 2021–2025 power-steering pump recall (26V-363).Mopar 68252490AC power steering pump reservoir, JL/JT · Quadratec ↗ |
| Brake & clutch fluid | Mopar DOT 3 (DOT 4 acceptable) | Flush on purchase, then every 2–3 years confirm in manual | Manual trucks share the fluid type in the clutch master cylinder.Mopar DOT 3 brake fluid · Quadratec ↗ |
| Driveline & front-end inspection | CV and U-joints, tie-rod ends, front suspension | Every 20,000 mi (factory schedule per Way of Life) | Lug nuts are 130 ft-lb (22 mm socket). Re-torque the track bar and steering hardware after any lift.Dana Spicer SPL30-1350XC driveshaft U-joint, 2012–2021 JK/JL · Quadratec ↗JL tie rods, ends and ball joints · ExtremeTerrain ↗ |