Specs, fluids & service · 1986–1992
Jeep Comanche MJ 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
| PLATFORM | MJ (XJ-based unibody with boxed rear frame) |
|---|---|
| PRODUCTION | 1985 (MY1986) – June 12, 1992, Toledo, Ohio |
| TOTAL BUILT | 190,446 |
| WHEELBASE | 113 in (6 ft bed) · 119.9 in (7 ft bed) |
| LENGTH | 179.2 in (SWB) · 194.0 in (LWB) |
| ENGINE | 4.0 L AMC I6 · 173–190 hp (1987–92) |
| OTHER ENGINES | 2.5 I4 · 2.8 GM V6 (1986) · 2.1 Renault TD (1986–87) |
| TRANSMISSIONS | A904 · AW4 auto · AX-4, AX-5, BA-10/5, AX-15 manual |
| TRANSFER CASE | NP231 Command-Trac / NP242 Selec-Trac, 2.72:1 |
| FRONT AXLE | Dana 30 (4WD) |
| REAR AXLE | Dana 35 · Dana 44 (Metric Ton) · Chrysler 8.25 (1991–92) |
| PAYLOAD | 1,400 lb · 2,205 lb (Metric Ton) |
By year
| YEARS | PLATFORM | ENGINE | OUTPUT | NOTES |
|---|---|---|---|---|
| 1986 | MJ (AMC), LWB only | 2.5 I4 · 2.8 GM V6 · 2.1 Renault TD | V6 slightly weaker than the I4 | Custom, X, XLS trims. NP207/NP228. A904 3-speed auto or AX-4/AX-5/BA-10/5. |
| 1987 | MJ, SWB added | 2.5 I4 · 4.0 I6 Renix | 121 hp · 173 hp / 220 lb-ft | AW4 auto. NP231/NP242. Chief, Laredo, Pioneer, SporTruck. Diesel dropped mid-year. |
| 1988–1990 | MJ (Chrysler), Renix | 2.5 I4 · 4.0 I6 | 177 hp / 224 lb-ft (4.0) | Eight-slot grille, Eliminator and Olympic Edition (1988). AX-15 replaces BA-10/5 mid-1989. |
| 1991–1992 | MJ HO | 2.5 I4 · 4.0 I6 HO | 130 hp · 190 hp / 225 lb-ft | Chrysler engine management. No automatic with the 2.5. Chrysler 8.25 rear available. |
| 1986–1992 | Metric Ton (LWB) | As above | — | Heavy-duty springs, wheels and tires and a Dana 44 rear; 2,205 lb payload. |
Fluids, capacities & service intervals
A Comanche is at least 34 years old, and most have spent years as cheap work trucks, so assume nothing has been done. The drivetrain is the XJ's, so the capacities below come from the 2001 Cherokee owner's manual as quoted on NAXJA, for the parts the two share. Check your own truck's manual and the axle tags, especially for Dana 44 and Metric Ton rear axles.
| ITEM | SPEC / CAPACITY | INTERVAL | NOTES & PARTS |
|---|---|---|---|
| Engine oil & filter | 4.0: 6.0 qt (5.7 L) with filter · 2.5: 4.0 qt (XJ figures) | Baseline now | Renix-era engines use a metric filter thread. Comanche Club members advise against Fram filters.Crown MFK8 master filter kit (oil, air, fuel), 1991–96 XJ & MJ · Quadratec ↗Comanche filter catalog (Renix years) · RockAuto ↗ |
| Ignition: plugs, wires, cap and rotor | Copper plugs, 0.035 in gap (4.0, XJ figure) | Baseline now | Clean the throttle body and IAC and set the TPS to spec while you're there; Comanche Club calls this routine on an old MJ.Crown spark plug, XJ & MJ 4.0L · Quadratec ↗Crown 83502400K2 spark plug wire set, CJ/YJ/XJ/MJ · Quadratec ↗ |
| Coolant & thermostat | 4.0: about 10.5 qt (XJ figure) confirm in manual | Flush and refill now | Check the plastic bottle for cracks. Renix trucks have the pressurized closed system.Crown 52027984 coolant bottle and cap, 1991–2001 XJ & MJ · Quadratec ↗Comanche cooling catalog · RockAuto ↗ |
| Clutch hydraulics | DOT 3 brake fluid | Inspect and flush now | Look for leaks above the fuse box.Crown 53004467 clutch master cylinder, 1987–90 XJ & MJ · Quadratec ↗ |
| Automatic transmission (AW4) | 4 qt drain-and-fill, 8 qt with filter (XJ figure) · Dexron III/Mercon per the 2001 manual quote confirm for your year | Baseline now | Do a pan drop and filter change, not a pressure flush.Crown AW4 transmission oil filter, XJ/MJ · Quadratec ↗Crown 83504032G transmission pan gasket, XJ/MJ · Quadratec ↗ |
| Manual transmission | AX-15 and AX-5: about 3.3 qt 75W-90 GL-3/GL-4, not GL-5 (NAXJA) · BA-10/5: confirm in manual | Baseline now | NAXJA notes some manuals wrongly list GL-5 for the Aisin boxes.Comanche manual transmission catalog · RockAuto ↗ |
| Transfer case (NP231 / NP242) | NP231: 2.2 pt · NP242: 2.85 pt · ATF (XJ figures) | Baseline now | 1986 trucks have the NP207 or NP228; check the tag.Crown NP231SP small parts kit, YJ/TJ/XJ/MJ · Quadratec ↗ |
| Front axle (Dana 30) & CAD | 2.5 pt (1.2 L) SAE 75W-90 (XJ figure) | Baseline now | Check that the vacuum axle disconnect actually engages before the first trail.Yukon YCGD30 Dana 30 diff cover gasket · Quadratec ↗Crown RT23002 manual axle disconnect kit, 1984–93 XJ & MJ · Quadratec ↗ |
| Rear axle (Dana 35 / Dana 44 / 8.25) | Dana 35: 3.5 pt · 8.25: 4.4 pt (XJ figures) · Dana 44: confirm in manual · SAE 75W-90 · friction modifier with Trac-Lok | Baseline now | Read the axle tag first. Comanche Club members note that some Dana 35s have a metal fill plug, not the rubber one most people expect.Crown Dana 35 differential cover, YJ/XJ/MJ · Quadratec ↗Yukon friction modifier additive · Quadratec ↗ |
| U-joints | Front axle shafts and both driveshafts | Inspect now | Turn the front wheels to full lock and check the axle U-joints for play.Crown 8126637BC front axle U-joint, CJ/YJ/XJ/MJ · Quadratec ↗Crown J8126614 1310 driveshaft U-joint, CJ/YJ/XJ/MJ · Quadratec ↗ |
| Brakes | DOT 3 fluid · front discs, rear drums | Flush now; then every 2 years | Rear drums usually need adjusting and fresh hardware. Comanche Club has a brake-upgrade write-up.Crown 52005350KE rear drum brake service kit, YJ/TJ/XJ/MJ · Quadratec ↗Crown 52008440K front disc brake service kit, YJ/TJ/XJ/MJ · Quadratec ↗ |
| Grounds & headlights | Engine, body, taillight and fuel-tank grounds | Clean now | Comanche Club members recommend a headlight relay harness for brighter lights and less load on the switch. If you remove the bed, re-ground the harness or it won't start.Crown RT28005 H4 headlight conversion kit, YJ/XJ/MJ · Quadratec ↗ |
Capability
| Towing | 5,000 lb (2,270 kg) 1992 4.0, per KBB |
|---|---|
| Payload | 1,400–1,475 lb · 2,205 lb Metric Ton Wikipedia; KBB lists 1,475 lb for 1992 |
| Fuel tank | 18 US gal (68 L) short bed · 23 US gal (87 L) long bed 1990, per iSeeCars |
| Fuel economy | EPA 18 city / 22 hwy 1992 4.0 long bed, per KBB |
| Curb weight | 2,895–3,231 lb (1,313–1,466 kg) 1990, 2WD short bed to 4WD Eliminator |
| Turning circle | 41.2 ft (12.6 m) 1992, per KBB |
| Wheelbase | 113 in (2,870 mm) SWB · 119.9 in (3,045 mm) LWB |
| Length | 179.2 in SWB · 194.0 in LWB |
Wheels & tires
| Factory tire | 205/75R15 (base, Pioneer) · 215/75R15 (base, Pioneer) · 225/75R15 (Pioneer) · 225/70R15 (Eliminator) |
|---|---|
| Bolt pattern | 5x114.3 (5x4.5") |
| Center bore | 71.5 mm |
| Lug thread | 1/2"-20 |
| Biggest tire · Stock | 235/75R15 (≈29 in) |
| Biggest tire · Stock, trimmed | 31x10.50R15 |
| Biggest tire · 3 in | 31x10.50R15 |
Common Jeep Comanche MJ repairs
- Replace rusted floor pans and rockersDIFFICULTY 4 / 5
- Replace a leaking clutch master cylinderDIFFICULTY 2 / 5
- Hot stalls and no-starts: CPS, ballast resistor, groundsDIFFICULTY 2 / 5
- Reseal the oil filter adapterDIFFICULTY 2 / 5
- Sort out the cooling system (and the Renix closed system)DIFFICULTY 2 / 5
- Rebush the rear leaf springs and shacklesDIFFICULTY 3 / 5
- Fix or bypass the front axle disconnect (CAD)DIFFICULTY 3 / 5
- Cure death wobble: track bar and steeringDIFFICULTY 3 / 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.