The 1973 Plymouth Duster is a solid A-body platform with legendary slant-six and small-block V8 reliability, but 50+ year-old metallurgy, emission controls, and discontinued rubber parts create predictable headaches.
Timing Chain Stretch and Gear Wear (All Engines)
Common · high severityTypical onset: 80,000-150,000 mi
Symptoms: Hard starting when hot, Retarded ignition timing that won't stay adjusted, Rattling from front of engine on cold start, Loss of power and poor fuel economy
Fix: Replace timing chain, gears, and front seal while you're in there. Slant-six takes 4-5 hours due to cramped access; V8s are 3-4 hours. Original nylon-toothed cam gears shed teeth after decades. Use double-roller chain kit, not single-row OEM replacement.
Estimated cost: $450-800
Torsion Bar Corrosion and Lower Control Arm Bushings
Common · medium severitySymptoms: Uneven ride height side-to-side, Clunking over bumps, Wandering steering, Excessive tire wear on inner edges
Fix: Torsion bars rust through at the hex ends after decades in salt states. Lower control arm bushings turn to powder. Complete front-end rebuild with new bars, bushings, ball joints, and alignment: 6-8 hours. Bars themselves are getting hard to source.
Estimated cost: $800-1,400
Fuel Tank and Sender Unit Failure
Occasional · medium severitySymptoms: Fuel gauge reads empty or erratic, Fuel leaks at tank seams, Smell of raw gas in trunk area, Won't draw fuel below 1/4 tank
Fix: Original tanks rust from inside out; ethanol fuel accelerated this. Sending units fail electrically or the float arm corrodes off. Tank replacement requires dropping exhaust and rear axle slightly: 4-5 hours. Aftermarket tanks are hit-or-miss on fit.
Estimated cost: $600-950
Carter BBD Carburetor Issues (318/360 Engines)
Common · low severitySymptoms: Rough idle when warm, Stumble on acceleration, Black smoke from exhaust, Won't pass emissions in tested states
Fix: The 1973 emissions carbs have vacuum-operated secondary systems that leak and stick. Rebuild kits help temporarily, but worn throttle shafts allow vacuum leaks you can't fix. Plan 2-3 hours for proper rebuild, or 1 hour to swap on an Edelbrock replacement and tune.
Estimated cost: $250-400 rebuild, $450-600 Edelbrock swap
Rear Window Seal Leaks and Quarter Panel Rust
Common · medium severitySymptoms: Water in trunk after rain, Wet carpet behind rear seat, Bubbling paint at quarter panel lower edges, Trunk floor rust-through
Fix: Rear window rubber shrinks and cracks; water runs down inside quarters and rots them from inside. If caught early, reseal window and treat rust: 3-4 hours. If quarters are gone, you're into patch panels or replacement quarters: 12-20 hours bodywork.
Estimated cost: $300-500 reseal, $1,800-3,500 quarter panel repair
Electronic Ignition Module Failure (If Not Already Converted)
Occasional · high severitySymptoms: Sudden no-start when hot, Intermittent stalling, Runs fine cold, dies after 20 minutes, No spark from coil
Fix: If still running original points, convert to electronic ignition (1 hour). If already electronic, the ECU box fails with heat cycling. Keep spare module in glovebox. Swap takes 15 minutes roadside with screwdriver.
Estimated cost: $120-220 conversion kit, $80-150 replacement module
Steering Column Bearing and Coupler Wear
Occasional · medium severityTypical onset: 100,000+ mi
Symptoms: Clunking when turning wheel, Steering wheel off-center but car tracks straight, Play in steering wheel independent of front-end play, Rubbing noise when turning
Fix: Upper bearing dries out, rag coupler at steering box deteriorates. Column must be dropped to replace bearing and coupler: 3-4 hours including steering wheel removal. Tilt columns add an hour.
Estimated cost: $350-550
Buy it if rust-free and the engine runs smooth—mechanical parts are available and straightforward, but bodywork will bankrupt you on a rusty one.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.