1987 CHEVROLET CELEBRITY

Typical onset: 80,000-140,000 mi

Symptoms: Slipping between 1st and 2nd gear, especially when cold, Delayed engagement into Drive or Reverse, Whining noise from torque converter, Shuddering during light throttle acceleration

Fix: The 3-speed THM-125C (also called 3T40) has weak direct clutches and governor issues. Rebuild requires 8-12 hours labor. Many shops recommend replacing oil cooler lines and external filter simultaneously. Fluid neglect kills these early—if it's never been serviced past 100K, budget for replacement not rebuild.

Estimated cost: $1,200-2,200

Typical onset: 70,000-120,000 mi

Symptoms: Coolant loss with no visible external leaks, White smoke from exhaust on cold start, Rough idle and misfire when warmed up, Milky residue on oil cap (if severe)

Fix: The composite intake gaskets deteriorate and allow coolant into the crankcase or cylinders. Requires 4-6 hours to remove plenum, replace gaskets, and reassemble. Always use updated Fel-Pro gasket set. Check for oil contamination—if coolant mixed into oil for more than a week, main bearings may be damaged.

Estimated cost: $450-750

Typical onset: 150,000-200,000 mi

Symptoms: Metallic knocking that changes with clutch engagement (manual trans), Excessive crankshaft endplay—can feel wobble at harmonic balancer, Clutch won't fully disengage or grinds going into gear

Fix: The Iron Duke's thrust bearing (center main) wears from clutch riding or heavy loads. Requires full engine removal and teardown—16-20 hours labor. Often discovered during clutch jobs. At this mileage and labor cost, many opt for junkyard long block swap instead of rebuild.

Estimated cost: $1,800-3,200

Typical onset: 60,000-100,000 mi

Symptoms: Clunking when shifting from Park to Drive, Excessive engine movement visible from wheel well during acceleration, Vibration at idle that worsens with A/C on

Fix: The rubber transmission mount deteriorates and the trans sags, stressing cooler lines and shift linkage. Replacement takes 1.5-2 hours with proper support of the powertrain. Always inspect cooler lines during this job—they crack where they contact the sagging trans.

Estimated cost: $150-280

Symptoms: No-start with no fuel pump prime sound when key turned on, Intermittent stalling that returns after car sits and cools, Starts fine cold, dies after 20 minutes of driving

Fix: The fuel pump relay (in engine compartment fuse block) develops cracked solder joints from heat cycling. Starts intermittently failing hot, then fails completely. Diagnosis takes 0.5 hours, relay replacement is 0.3 hours. Some techs resolder the board instead of replacing—works but not a permanent fix.

Estimated cost: $80-150

Symptoms: Brake fluid loss with visible drips near rear axle, Soft brake pedal that goes to floor, Rust perforation visible on steel brake lines above rear axle

Fix: Steel brake lines that run along the rear axle and over the fuel tank rust through in salt states. Requires replacing entire rear section from proportioning valve back—4-6 hours with proper double-flaring and bleeding. Cannot patch—must replace full sections with pre-bent lines or NiCopp.

Estimated cost: $400-700