1971 DODGE CORONET

Typical onset: 80,000-150,000 mi or unknown history

Symptoms: rattling on cold start that fades as oil pressure builds, rough idle and poor performance, backfiring through carburetor, won't start or hard starting with ignition timing jumping around

Fix: Replace timing chain, gears, and tensioner. Original single-row chains stretch badly. Expect 4-6 hours labor for accessible engines like 318/360, up to 8 hours for big-blocks with AC and power steering. Double-roller chain upgrade recommended. Cam inspection while open adds minimal time.

Estimated cost: $600-1,200

Symptoms: clunking over bumps, uneven ride height side-to-side, excessive tire wear on inside edges, steering wander and vague handling, visible rust through frame rails at torsion bar sockets

Fix: Torsion bar anchors rust out from road salt and moisture. Lower control arm bushings fail, and ball joints wear. Requires frame inspection—if anchor pockets are gone, welding/plating needed before suspension rebuild. Plan 8-12 hours for full front-end overhaul including alignment. Some frames are too far gone.

Estimated cost: $1,200-2,800

Symptoms: visible holes in driver/passenger floor under carpet, trunk floor feels spongy or has rust holes near quarters, fuel smell in cabin from tank strap area rust, dampness and mold smell inside

Fix: B-body floors trap water from clogged drain holes and leaking windshield seals. Patch panels exist but proper repair requires cutting out old metal and welding in new. DIY with welder: 20-30 hours. Shop labor: 16-25 hours depending on extent. Fuel tank must come out for trunk floor work.

Estimated cost: $1,800-4,500

Symptoms: hard starting when hot, rough idle and stalling at stops, flooding and fuel smell, black smoke from exhaust, hesitation on acceleration

Fix: Original carbs are now 50+ years old. Gaskets harden, accelerator pump diaphragms crack, float needles stick. Full rebuild kit runs $50-80, labor 2-3 hours if staying with original. Many owners swap to Edelbrock Performer or Holley for reliability. Tuning these old carbs properly requires experience.

Estimated cost: $200-600

Symptoms: flickering headlights or dash lights, ammeter needle swinging wildly or stuck, burning smell from dash, intermittent electrical failures, melted wiring at firewall bulkhead connector

Fix: Factory bulkhead connectors corrode and create high resistance, causing heat and failure. Ammeter circuit can overheat and start fires. Proper fix: clean and re-pin bulkhead (3-4 hours) or install MAD Electrical bypass. Ammeter bypass adds 2 hours. Voltage regulator and alternator often need replacement concurrently.

Estimated cost: $400-900

Typical onset: 60,000-120,000 mi

Symptoms: gear oil dripping from axle tubes onto brakes, whining or howling from rear on acceleration or deceleration, clunking when engaging drive, axle shaft play in/out

Fix: Axle seals dry out and fail, contaminating rear brakes. Pinion seal leaks are also common. Differential bearings wear if fluid was neglected. Seal replacement: 2-3 hours per side. Full differential rebuild if noisy: 6-8 hours including gear setup. 8.75" (Dana-style) is rebuildable; parts available.

Estimated cost: $300-1,400

Symptoms: groaning or whining when turning at low speed, fluid puddles under front of car, heavy steering effort when cold, hissing noise from pump

Fix: Factory Saginaw pumps and gearboxes leak from aged seals. Pump rebuild or replacement: 2 hours. Gearbox reseal/rebuild: 4-6 hours if you pull and bench-rebuild it. Hoses also crack and weep. Aftermarket pumps are hit-or-miss; quality rebuilds preferred. Flush system with fresh ATF after repair.

Estimated cost: $350-800