Specs, fluids & service · 2004–2006
Jeep Wrangler Unlimited (LJ) specs, fluids and service intervals
The numbers you need in the garage, on one page: spec sheet, capacities and service intervals, wheels and tires, and the parts to order. Sourced from owners, specialists and the factory; tags marked confirm in manual haven't been checked against a factory source yet.
Spec sheet
| CODE | LJ (TJ long wheelbase) |
|---|---|
| MODEL YEARS | 2004.5–2006 |
| ASSEMBLY | Toledo, Ohio |
| ENGINE | 4.0 L OHV I6, 190 hp / 235 lb-ft |
| TRANSMISSIONS | 42RLE 4-spd auto · NSG370 6-spd manual (2005–06) |
| TRANSFER CASE | NV231 (2.72:1) · NV241 Rock-Trac (4:1, Rubicon) |
| AXLES | Dana 30 / Dana 44 LSD · Rubicon: Dana 44 / Dana 44, air lockers |
| WHEELBASE | 103.4 in |
| LENGTH | 167 in (171 in with spare) |
| DEPARTURE / BREAKOVER | 27.7° / 21.4° |
| TOWING | 3,500 lb |
| FUEL TANK | 19 gal |
| PRODUCTION | ≈46,000–47,000 (Driving Line, Jalopnik) |
By year
| YEARS | PLATFORM | ENGINE | OUTPUT | NOTES |
|---|---|---|---|---|
| 2004.5 | LJ (Unlimited) | 4.0 L I6 | 190 hp / 235 lb-ft | Launched April 2004 at $24,995. Dana 44 limited-slip rear (3.73), NV231 transfer case; Jeep's 2004½ spec sheet lists the 42RLE automatic. |
| 2005–2006 | LJ (Unlimited) | 4.0 L I6 | 190 hp / 235 lb-ft | NSG370 six-speed replaces the five-speed manual. Watch for OPDA wear on 2005–06 engines. |
| 2005–2006 | LJ Rubicon (Rubicon Unlimited) | 4.0 L I6 | 190 hp / 235 lb-ft | Dana 44 front and rear with air lockers, 4:1 Rock-Trac, 4.10 gears, LT245/75R16 MT/Rs, diamond-plate rockers. |
| 2005 | Sahara Edition Unlimited Rubicon | 4.0 L I6 | 190 hp / 235 lb-ft | 1,000 numbered, all Light Khaki, tied to the film Sahara. Manual and automatic versions. |
| 1997–2006 | TJ (short wheelbase), for reference | 2.5 / 2.4 I4, 4.0 I6 | Up to 190 hp | 93.4 in wheelbase, 2,000 lb tow rating, Dana 35 rear on many trims. See the TJ page. |
Fluids, capacities & service intervals
Assume nothing has been done. Even a low-mile LJ is now 20 years old, so rubber, coolant and gear oil have aged regardless of mileage. On 2005–06 trucks, put the OPDA at the top of the list. On every LJ, put the frame inspection there too, before you spend a cent on mods.
| ITEM | SPEC / CAPACITY | INTERVAL | NOTES & PARTS |
|---|---|---|---|
| Engine oil & filter | SAE 10W-30 · 6 qt with filter (4.0 L) | Then per the owner's manual schedule confirm in manual | Look at the oil-filter adapter gasket and the rear main seal while you're under there: both are common 4.0 leak points.Mopar 05281090AB engine oil filter, 2001–07 TJ · Quadratec ↗ |
| Oil pump drive assembly (2005–06) | Updated OPDA with relocated seal | Once, unless there are receipts | Listen for the 'laughing monkey' squeal; the replacement must be indexed to keep the cam sensor in sync.Crown oil pump drive, 2005–06 4.0 TJ · ExtremeTerrain ↗ |
| Engine air filter | Factory airbox element | Inspect at every oil change; more often on dusty trails | confirm part fitment for your intakeTJ replacement air filters · Quadratec ↗ |
| Spark plugs | 6 plugs (Crown 56041402AB listed for 1999–06 TJ & Unlimited) | Replace now if there's no record confirm in manual | Check the plug wires and coil while you're there.Crown Automotive 56041402AB spark plug · Quadratec ↗ |
| Coolant, thermostat & hoses | 10.5 qt (4.0 L); coolant type per the cap/manual confirm in manual | Flush now; replace the thermostat and hoses if they're original | Inspect the radiator's plastic end tanks for seepage at the upper seams, a known 100k-mile failure.Mopar 52028186AC thermostat, 1997–06 TJ · Quadratec ↗Fairchild MCH1064 upper radiator hose, TJ 4.0 · Quadratec ↗TJ water pumps · Quadratec ↗ |
| Serpentine belt | Crown 4060882 listed for 2000–06 TJ & Unlimited 6-cyl | Replace if it's cracked, glazed or of unknown age | Spin the tensioner and idler pulleys while the belt is off.Crown Automotive 4060882 accessory drive belt · Quadratec ↗ |
| Automatic transmission (42RLE) | ATF+4 · 4 qt service fill | Drain and refill now, with a new filter | A service fill only replaces part of the fluid. Do two drain-and-fills rather than a high-pressure flush.ATF+4 (search) · Quadratec ↗ |
| Manual transmission (NSG370) | 3.17 pints; Mopar Manual Transmission Lubricant (as specified for the NSG370) confirm in manual | Change now if there's no record | The NSG370 uses a hydraulic clutch with a dual-mass flywheel. Check the clutch fluid (DOT 3) too.Mopar manual transmission lubricant (search) · Quadratec ↗ |
| Transfer case | NV231: 2.2 pints · NV241 Rock-Trac: 4.2 pints · ATF+4 | Change now | Check the output seals and the shifter-linkage bushings at the same time.ATF+4 (search) · Quadratec ↗ |
| Front & rear differentials | Dana 30: 2.5 pints · Dana 44: 4.0 pints · GL-5 80W-90 or 75W-140 synthetic; Rubicon 75W-140; Trac-Lok rear needs 4 oz of limited-slip additive | Change both now, and after any deep water crossing | Standard LJs have a limited-slip Dana 44 rear, so don't forget the friction modifier.75W-140 synthetic gear oil (search) · Quadratec ↗Limited slip additive (search) · Quadratec ↗ |
| Driveshaft & front axle U-joints | Greasable 1310 driveshaft joints · axle-shaft U-joints | Grease now and at every oil change if greasable | Check for play by hand. A front axle U-joint that binds on slow turns is due.Crown Automotive 8126614SP greasable 1310 U-joint, TJ & Unlimited · Quadratec ↗Crown Automotive 8126638SP front axle U-joint · Quadratec ↗ |
| Brake & clutch fluid | DOT 3 | Flush now, then every 2–3 years confirm in manual | Manual LJs share the brake fluid type in the clutch hydraulics.Brake fluid (search: DOT 3) · Quadratec ↗ |
| Front-end inspection & toe | Track bar, tie rods, drag link, ball joints, bushings | Now, and after any lift or hard trail day | Re-torque the front-end hardware. Set toe to about 1/16 in in, then get a proper alignment.Crown Automotive 52088431 front track-bar bushing · Quadratec ↗ |
| Frame & body-mount inspection | Rear lower control-arm mounts, transfer-case crossmember, center body mounts | Now, then every spring in salt country | Clean, treat and oil the frame inside and out. Catching surface rust now saves a welder later.Rust Buster TJ frame sections · Quadratec ↗ |
Capability
| Towing | 3,500 lb (1,588 kg) against 2,000 lb for a short-wheelbase 4.0 TJ |
|---|---|
| Payload | 800 lb (363 kg) |
| Fuel tank | 19 US gal (72 L) |
| Ground clearance | 8.3 in (212 mm) rear axle · 9.2 in (235 mm) running 2004½ Unlimited |
| Approach / departure / breakover | 43.1° / 27.7° / 21.4° 2004½ Unlimited |
| Turning circle | 36 ft (11.2 m) curb to curb |
| Curb weight | 3,721 lb (1,689 kg) Unlimited · 3,977 lb (1,804 kg) Unlimited Rubicon Unlimited figure from Jeep's 2004½ spec sheet (Rockcrawler); Rubicon Unlimited figure confirm in your manual against a 2005–06 spec sheet |
| Cargo volume | 28.5 cu ft (0.807 m³) |
| Fuel economy | EPA 13 city / 16 hwy (auto) · 13 / 17 (six-speed) 2005–06 Wrangler 4.0 ratings; EPA has no separate Unlimited listing |
Wheels & tires
| Factory tire | 30x9.5R15 LT on 15x8 cast-aluminum wheels (Unlimited) · 245/75R16 Goodyear MT/R (Unlimited Rubicon) |
|---|---|
| Bolt pattern | 5x114.3 (5x4.5") |
| Center bore | 71.5 mm |
| Lug thread | 1/2"-20 (60° cone seat) |
| Biggest tire · Stock | 31 in |
| Biggest tire · 2 in | ≈31 in |
| Biggest tire · 3 in | 33 in |
Open the Jeep Wrangler Unlimited (LJ) in the tire fitment tool →
Common Jeep Wrangler Unlimited (LJ) repairs
- Replace the oil pump drive assembly (2005–06 4.0)DIFFICULTY 3 / 5
- Repair rotted rear control-arm frame mountsDIFFICULTY 5 / 5
- Hunt down death wobble and set toe in the drivewayDIFFICULTY 2 / 5
- Replace the radiator before the plastic tank lets goDIFFICULTY 2 / 5
- Replace a throttle position or crank sensorDIFFICULTY 1 / 5
- Fix a transfer case that won't go into 4-LowDIFFICULTY 1 / 5
- Replace a front axle U-joint and unit bearingDIFFICULTY 3 / 5
- Stop the rear main seal leakDIFFICULTY 4 / 5
Always confirm torque figures, fluids and capacities against the factory service manual for your VIN. See the disclaimer; some parts links are affiliate links.