| Engine oil & filter | 3.6: 6 qt SAE 5W-20 meeting MS-6395 (5W-30 permitted) · 3.8: 6.0 qt with filter, 5W-20 or 5W-30 per the filler cap | Then per the oil-life monitor or owner's manual confirm in manual | The Pentastar uses a cartridge filter under a 24 mm cap on top of the engine. Quadratec notes the filter changed for 2014, so buy for your year, and says to pull the old element gently because the pressure-relief valve is in the cap. Don't overtighten the cap; Curbside Classic gives 18 lb-ft.aFe Pro Guard D2 oil filter (4-pack), 2012–2013 JK 3.6 · Quadratec ↗JK oils and fluids · ExtremeTerrain ↗Oil filter catalog, 2015 Wrangler · RockAuto ↗ |
| Engine air filter | Panel filter in the airbox | Inspect at every oil change; more often on dusty trails | If a snorkel or aftermarket intake is fitted, check the clamps and seals as well as the element.Crown 53034018AE replacement air filter, 2007–2018 JK · Quadratec ↗ |
| Cabin air filter | Quadratec lists JK cabin filters from the 2011 model year on | Replace when dirty confirm in manual | Quadratec lists separate cabin filters for 2011–2013 and later JKs.Crown 55111302AA cabin air filter 2-pack, 2011–2013 JK · Quadratec ↗ |
| Spark plugs | 3.6 Pentastar: 0.043 in (1.10 mm) gap | KBB's schedule lists spark plugs at 100,000 mi | Pentastar plugs are under the intake plenum on the rear bank, so it's a good time to look for oil filter housing seepage. 3.8 plugs: confirm in manual.Mopar SP149125AF spark plug, 2012–2024 JK/JL 3.6 · Quadratec ↗OMIX 17248.12 spark plug, 2012–2020 JK/JL V6 · Quadratec ↗ |
| Coolant, thermostat & hoses | 3.8 and 2012 3.6: HOAT 5-year/100,000-mile, about 13 qt · 2013–18 3.6: Mopar 10-year/150,000-mile OAT (MS.90032), 10.5 qt (ExtremeTerrain) | KBB's schedule lists coolant at 100,000 mi; inspect hoses at every service | Don't mix HOAT and OAT; check what's in the tank before topping up. On a 3.6, a coolant leak in the valley can come from the oil cooler, not the water pump.Mopar 68163848AB antifreeze coolant (concentrate) · Quadratec ↗Crown 68210220AA thermostat, 2007–2011 JK · Quadratec ↗Crown 55111394AC upper radiator hose, 2012–2018 JK · Quadratec ↗ |
| Automatic transmission | W5A580 (2012–18): Mopar ATF+4, 5.3 qt service fill / 8.1 qt overhaul · 42RLE (2007–11): ATF+4, about 4.0 qt drain-and-fill / 8.8 qt total | KBB lists transmission fluid at 100,000 mi; sooner if you tow or run big tires | Driving Line says heat kills both automatics, especially with oversized tires, towing or hard off-road use, and recommends an auxiliary cooler and proper gearing. A drain-and-fill with a new filter is the usual DIY.Mopar 68218058AC ATF+4, 2009–2016 JK · Quadratec ↗Mopar 52108325AA transmission oil filter, 2012–2018 JK · Quadratec ↗ |
| Manual transmission (NSG370) | Mopar manual transmission lubricant meeting MS-9224 · 1.6 qt | Change on a truck with unknown history confirm in manual | Driving Line says the NSG370 can grind, pop out of gear and get noisy, and recommends regular fresh fluid. A 2007 lube chart gives 22 ft-lb for the fill and drain plugs.JK oils and fluids · ExtremeTerrain ↗ |
| Transfer case (NV241 Command-Trac / Rock-Trac) | Mopar ATF+4 · 2.1 qt | Change on purchase, then per the severe-service schedule confirm in manual | Remove the fill plug before the drain plug. Both are chain-driven cases with aluminum housings (Driving Line), so don't overtighten the plugs.Mopar 68218058AC ATF+4 · Quadratec ↗ |
| Front axle | GL-5 80W-90 · Dana 30 (186 FBI): 2.1 pt · Dana 44 (216 FBI, Rubicon): 2.7 pt | Change on purchase and after deep water crossings | If the oil looks milky, water has got in through the axle vent or seals.Yukon 80W-90 conventional gear oil · Quadratec ↗Gear oil 80W-90 (search) · Quadratec ↗ |
| Rear axle (Dana 44) | GL-5 80W-90 · 226 RBI: 4.75 pt · synthetic 75W-140 for trailer towing · add 4 oz Mopar limited-slip additive to Trac-Lok axles | Change on purchase; more often if you tow | A tag on the cover marks a limited-slip axle. Rubicon lockers don't need friction modifier.Yukon 80W-90 conventional gear oil · Quadratec ↗Currie CE-9013S 75W-140 gear oil · Quadratec ↗ |
| Power steering fluid | Mopar Power Steering Fluid +4 or Mopar ATF+4 | Refresh the reservoir if the fluid is dark | Big tires work the steering box hard. Look for leaks at the box and the pressure lines.Mopar 68218058AC ATF+4 · Quadratec ↗ |
| Brake & clutch fluid | Mopar DOT 3 (DOT 4 acceptable if DOT 3 isn't available) | 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 ↗ |
| U-joints & driveshafts | Front axle-shaft U-joints, plus driveshaft joints where greaseable | Inspect at every oil change; grease any zerks | Rubicon Dana 44 front U-joints take a beating with lockers and big tires, so carry a spare.Dana Spicer SPL30-7166XC Blue Series Dana 44 front axle U-joint, JK Rubicon · Quadratec ↗Dana Spicer SPL30-1350XC driveshaft U-joint, 2012–2021 JK/JL · Quadratec ↗ |
| PCV valve | Engine-specific | Inspect with the plugs | A sticking PCV valve adds to oil consumption, which matters on a 3.8.Mopar 68083202AC PCV valve, 2012–2018 JK 3.6 · Quadratec ↗ |