Jeep Comanche • Best & Worst Years (1986–1992)
The Ultimate Full-Detail Reliability Guide
📖 What Defines a “Best” or “Worst” Year?
The Comanche’s reputation hinges on three core components: engine, transmission, and rust prevention. The best years (1988–1990) feature the rugged 4.0L AMC inline-six (Renix) paired with the Aisin AW-4 auto or AX-15 manual. The worst years (1986 and early 1987) suffer from the GM 2.8L V6 (prone to overheating, blown heads) and the Peugeot BA-10/5 manual – a transmission with glass internals. Later 1991-92 4.0L HO are good but have minor sensor quirks.
📊 Year-by-Year Detailed Analysis: Ratings & Red Flags
| Year | Engines Available | Transmission (problematic?) | Reliability Score | Verdict & Known Issues |
|---|---|---|---|---|
| 1986 | 2.5L I4 (good), 2.8L V6 (awful) | BA-10/5, TF904 auto | ⭐ 1.5/5 | AVOID – V6 overheats, cracks heads; weak rear axle; electrical gremlins. Only buy for full drivetrain swap. |
| 1987 | 2.5L, 2.8L, early 4.0L | BA-10/5 (standard manual) | ⭐⭐ 2.3/5 | CAUTION – 4.0L is decent but BA-10 fails. Late 87 saw limited AX-15? Rare. Avoid 2.8L. |
| 1988 | 4.0L Renix, 2.5L | AX-15 / AW-4 (best) | ⭐⭐⭐⭐⭐ 5/5 | BEST YEAR – Renix 4.0L matured, bulletproof cooling, robust electrical grounds. Rust minimal in southern trucks. |
| 1989 | 4.0L Renix, 2.5L | AX-15 / AW-4 | ⭐⭐⭐⭐⭐ 5/5 | ELITE – identical to 1988, high collector demand. Excellent part availability. |
| 1990 | 4.0L Renix | AX-15 / AW-4 | ⭐⭐⭐⭐⭐ 4.9/5 | TOP PICK – final Renix, peak reliability + upgraded serpentine belt system. |
| 1991 | 4.0L High Output | AX-15 / AW-4 | ⭐⭐⭐⭐½ 4.5/5 | More power (190hp), but HO electronics and occasional idle issues; rust continues. |
| 1992 | 4.0L HO, rare 2.5L | AX-15 / AW-4 | ⭐⭐⭐⭐ 4.2/5 | Good but low production; some interior trim brittle. Still miles better than pre-88 V6. |
🔍 Detailed Year Cards: What You Get (Best & Worst Highlights)
1986
❌ Worst ever: 2.8L V6 115hp, BA-10 transmission grenades, rust prone. Definition of “worst” – only for restomods.
1987
4.0L appears but BA-10 remains fragile. Avoid 2.8L. Check transmission carefully.
1988
Best Year – 4.0L Renix + AX-15/AW-4 combo, Dana 44 possible. Rust treatment improved.
1989
Identical to 1988, easy to find spares, bulletproof cooling. Excellent off-road platform.
1990
Renix final iteration. Robust. Some MJ specific interior parts unique.
1991–92
4.0L High Output, AX-15, better fuel injection, but odd electrical gremlins possible.
🧩 Types of Jeep Comanche: Trims, Bed Styles & 4×4 Systems
Comanche types include: Base, Custom, Pioneer (upgraded interior), Chief (off-road decals, fog lights), Laredo (luxury bucket seats, carpet), Eliminator (sporty bodywork, 1991-92). Bed lengths: 6-foot (short bed) and 7-foot (long bed). 4×4 utilizes Command-Trac NP231 transfer case (except early NP207). The best type for off-road is a 1988-1990 Chief or Laredo with 4.0L, Dana 44 rear axle (rare but legendary). Avoid 2WD if you want resale value.
🛠️ How to Inspect a Used Jeep Comanche (Pre-purchase Bible)
🔧 Step-by-Step Inspection Checklist
- 🔍 Rust hot zones: Floor pans, rear “torque boxes” (near rear leaf spring mounts), lower door skins, and bed floor above rear axle. Frame unibody rust is terminal.
- ⚙️ Engine: If it has 2.8L V6 – walk away. 4.0L: check for oil leaks (rear main seal common), listen for knock, perform compression test (min 120 psi).
- 📀 Transmission: Identify BA-10 (10-bolt top) → avoid. AX-15 (cast iron top cover) or AW-4 are gold. Test drive: smooth shifts, no grinding.
- 🌡️ Cooling system: Overheating kills Renix 4.0L heads. Check for milky oil, pressurized coolant tank.
- ⚡ Electrical: Renix era grounds fail — inspect battery ground, engine ground strap. Test all lights, HVAC blower.
- 🧰 Rear axle: Dana 35 (c-clip) vs Dana 44 (stronger, more valuable). Look for rear diff tags or count bolts.
- 📜 Proof of maintenance: Records of recent cooling system, transmission fluid changes, rust repair.
💡 Pro tip: Bring a small mirror and flashlight to check hidden frame sections. The best Comanches come from dry Southwestern states (Arizona, Nevada).
⚠️ Is the Jeep Comanche Safe? Modern vs Historical Safety
Is it safe by 2025 standards? No. The Comanche has no airbags, no anti-lock brakes, no electronic stability control, and a primitive crumple zone. Crash protection is minimal; the NHTSA never tested it. However, with 3-point seatbelts (retrofit later models) and rust-free structure, it can be driven cautiously. Worst safety years: 1986-1987 lack shoulder belts for rear passengers. Advantage: Excellent visibility and maneuverability. For daily highway use, not recommended; best for backroads, farm duty, or off-road adventure.
✅ Advantages of the Best Years (1988-1990)
- Legendary 4.0L straight-six: easily 300k+ miles, endless torque.
- Simplicity & DIY friendly: parts shared with XJ Cherokee (millions made).
- Solid front axle (Dana 30) – excellent off-road articulation.
- Compact size – fits tight trails, easy to park.
- Aftermarket support: lift kits, bumpers, lockers widely available.
❌ Disadvantages & Worst-Year Pitfalls
- Structural rust is the number one killer – expensive to repair.
- 1986-1987 2.8L V6 – unreliable, gutless, parts obsolete.
- Peugeot BA-10 transmission – fails between 80k-120k miles.
- Poor fuel economy: 4.0L averages 13–17 MPG.
- Unibody weakness when overloaded – avoid heavy towing.
🚜 Use Cases: Daily, Off-Road, Farm, Restoration
Best use for a Comanche: light-duty off-roading, overlanding, ranch truck, or collector vehicle. The 1988-1990 4×4 long bed is ideal for hauling gear and camping. If you want a daily driver, budget for cooling system upgrades (open radiator conversion) and rust prevention. Worst use case: heavy towing (max capacity ~2,000 lbs) or salted winter roads without rustproofing. Many enthusiasts swap in later XJ parts for modern reliability. The Comanche shines as a vintage adventure rig.
