1987 AMC EAGLE

Typical onset: 80,000-140,000 mi

Symptoms: Slipping between gears, especially 1-2 shift, Delayed engagement when shifting into drive, Overheating (trans temp warning or burnt fluid smell), Metal shavings in pan during fluid changes

Fix: The Chrysler automatics weren't engineered for constant AWD duty and the viscous coupling adds heat and stress. Transmission cooler lines and the cooler itself fail, leading to overheating and clutch pack/band failure. Rebuild with upgraded clutches and bands runs 12-16 hours labor, plus external cooler upgrade recommended. Full replacement with junkyard unit is common cost-saving alternative.

Estimated cost: $1,800-3,200

Typical onset: All ages/mileages due to rubber degradation

Symptoms: Front hubs won't engage (loss of AWD, becomes RWD-only), HVAC stuck on defrost regardless of control position, Cruise control inoperative or surging, Hissing sounds under dash or near transfer case

Fix: The Eagle uses vacuum for front axle engagement, HVAC doors, and cruise. 35+ year-old rubber lines crack and collapse. Requires systematic tracing and replacement of vacuum lines from intake manifold to axle disconnect solenoids, HVAC actuators, and cruise servo. Budget 4-6 hours for thorough diagnosis and replacement of all suspect lines.

Estimated cost: $300-600

Typical onset: 120,000-180,000 mi

Symptoms: Deep knocking from lower block, worse when cold or under load, Oil pressure dropping below 10 psi at hot idle, Metallic debris in oil filter during changes, Visible bearing material on oil pan magnet

Fix: The 258 I6 is legendary for longevity BUT neglected oil changes or using non-detergent oils (common in the '80s/'90s) leads to sludge and bearing failure. In-chassis bearing replacement requires oil pan, timing cover, and crankshaft main cap removal—14-18 hours for mains and rods. Many opt for used long block swap instead at 12-15 hours.

Estimated cost: $2,200-4,000

Typical onset: 100,000-150,000 mi

Symptoms: Grinding or growling noise from center of vehicle, Vibration at highway speeds that changes with throttle input, Milky or metallic fluid on dipstick, Difficulty shifting into or out of low range

Fix: The NP119 or NP129 transfer case runs continuously and fluid is often never changed. Viscous coupling wears, chain stretches, bearings fail. Fluid service every 30k can prevent this, but most are neglected. Rebuild requires case removal (6-8 hours), plus internal parts. Used replacements from salvage are common fix.

Estimated cost: $1,200-2,000

Symptoms: Hard starting when cold, requires excessive cranking, Hesitation or stumble during acceleration, Black smoke from exhaust (running rich), Rough idle, especially when warm, Poor fuel economy (under 14 mpg city)

Fix: The Carter BBD two-barrel is simple but suffers from dried-out accelerator pump diaphragms, clogged jets from ethanol fuel, and worn throttle shafts causing vacuum leaks. Complete rebuild kit with careful attention to float level and choke adjustment takes 3-4 hours for someone experienced with carbs. Many owners convert to Weber 32/36 or Motorcraft 2150 instead.

Estimated cost: $250-500

Typical onset: 60,000-120,000 mi

Symptoms: Clunking from front axle when starting from stop, Grinding noise when turning at low speed, Inability to engage front axle (RWD-only operation), Four-wheel-drive indicator light flashing or inoperative

Fix: The vacuum-operated front axle disconnect uses a shift motor and solenoid that corrode internally or lose vacuum. Axle must be partially disassembled to access shift collar and motor. Many owners eliminate the disconnect system entirely and run full-time AWD with welded or aftermarket hubs. Repair takes 3-5 hours per side.

Estimated cost: $400-800

Symptoms: Ticking or tapping noise from engine bay, worse when cold, Exhaust smell in cabin with heater on, Visible soot streaks on manifold surface, Failed emissions test due to pre-cat oxygen sensor readings

Fix: Cast iron manifolds crack between ports 3-4 from thermal cycling. The 258's manifold is relatively accessible—removal and replacement with new or used manifold takes 3-4 hours. Studs often break during removal, adding time for extraction and retapping.

Estimated cost: $350-650