1972 DODGE CHALLENGER

Typical onset: 60,000-100,000 mi

Symptoms: rattling noise from front of engine at startup, rough idle and poor performance, backfiring through carburetor, difficulty starting when hot, sudden loss of power if chain jumps or breaks

Fix: Replace timing chain, gears, and tensioner. On small-blocks (318/340/360), this is a front cover-off job requiring 6-8 hours. Big-blocks (383/400/440) take 8-10 hours due to tighter engine bay. Should also replace oil pump drive gear and front seal while in there. Original single-row chains wear faster than modern double-row replacements.

Estimated cost: $800-1,500

Symptoms: hard starting especially when warm, fuel smell in engine bay, hesitation or stumbling on acceleration, black smoke from exhaust, gas dripping from carb or air cleaner

Fix: Original Carter or Holley carbs develop worn needle/seat assemblies, stuck floats, and deteriorated accelerator pump diaphragms after sitting. Full rebuild takes 3-4 hours including removal, bench work, and tuning. Many owners upgrade to Edelbrock or newer Holley units. Fuel lines and rubber hoses also crack with age requiring replacement.

Estimated cost: $400-900

Typical onset: 80,000+ mi

Symptoms: front end sits low with uneven ride height, clunking over bumps, wandering steering, excessive body roll in turns, uneven tire wear

Fix: Torsion bars themselves rarely fail but supporting components do. Upper and lower control arm bushings deteriorate causing play. Ball joints wear and create dangerous looseness. Sway bar links and bushings need replacement. Complete front suspension rebuild with torsion bar adjustment takes 10-12 hours. Often need to heat and penetrate seized adjustment bolts.

Estimated cost: $1,200-2,200

Symptoms: intermittent or no-start conditions, gauges reading erratically or not at all, dimming lights, alternator not charging properly, electrical accessories cutting out

Fix: Five decades of heat cycles destroy wiring insulation, especially in bulkhead connector and under-dash harnesses. Ammeter bypass is critical safety modification (2 hours). Expect to chase multiple grounds and connections. Voltage regulator and ignition switch failures common. Full electrical diagnosis and repair of typical issues takes 6-10 hours depending on what's been modified or hacked over the years.

Estimated cost: $500-1,800

Typical onset: 70,000-120,000 mi

Symptoms: clunking when engaging drive or reverse, whining or howling at highway speeds, gear oil leaking from pinion seal or axle tubes, vibration during acceleration

Fix: 8.25" and 8.75" Dana/Chrysler rear ends are robust but suffer from worn carrier bearings and pinion seals. Pinion seal replacement is 2-3 hours but often leads to discovering worn bearings requiring full rebuild (8-12 hours). Ring and pinion noise indicates imminent failure. Sure-Grip limited slip units need clutch pack service or replacement. U-joints in driveshaft fail and can damage yoke or transmission output shaft if neglected.

Estimated cost: $600-2,500

Symptoms: ticking or tapping sound from engine bay, exhaust smell in cabin, visible cracks in cast iron manifolds, failed emissions test if applicable

Fix: Cast iron exhaust manifolds crack from heat cycling, especially on big-blocks where engine bay heat is extreme. Passenger side more prone due to tighter clearances. Replacement requires removing multiple accessories and heat shields. Allow 4-6 hours per side. Aftermarket headers are common upgrade but create their own fitment and clearance headaches. Studs often break requiring extraction.

Estimated cost: $400-1,000