1973 PONTIAC FIREBIRD TRANS AM

Typical onset: original mounts typically fail by 60,000-80,000 mi, but most surviving examples have aged-out rubber regardless of miles

Symptoms: Severe clunking when shifting into Drive or Reverse, Excessive drivetrain movement visible from outside during acceleration, Transmission tunnel contact noise over bumps, Shifter vibration at idle

Fix: Replace transmission mount and crossmember bushings; inspect engine mounts simultaneously as they fail from same age-related degradation. 2-3 hours labor for transmission mount, add 1.5 hours if doing engine mounts同时

Estimated cost: $300-600

Typical onset: typically surfaces after 40+ years regardless of mileage due to rubber hose deterioration and steel line corrosion

Symptoms: ATF puddles under front of vehicle, Transmission overheating and slipping under load, Pink or brown coolant in radiator (if internal cooler leaks), Delayed or harsh shifting when hot

Fix: Replace all rubber cooler lines and inspect steel lines for rust-through; flush and refill TH400 with fresh Dexron. If radiator internal cooler compromised, requires radiator replacement or external cooler conversion. 2-4 hours labor depending on routing complexity and radiator condition.

Estimated cost: $400-1,200

Typical onset: depends entirely on maintenance history; poor oil change intervals cause failure 60,000-100,000 mi, but well-kept engines exceed 150,000 mi

Symptoms: Deep knocking from crankcase at idle, worse under load, Oil pressure drops below 10 psi hot at idle, Metallic debris in oil filter or pan, Sudden catastrophic loss of power with violent internal noise

Fix: Full engine-out rebuild: crankshaft inspection and possible turning or replacement, all main and rod bearings, piston rings minimum. If crank damaged beyond .030" undersize, aftermarket crank required. Expect 40-60 shop hours for proper disassembly, machine work coordination, reassembly, break-in.

Estimated cost: $5,500-12,000

Symptoms: Hesitation or stumble on acceleration from idle, Raw fuel smell and black smoke at idle or cruise, Hard starting when hot, floods easily, Fuel weeping from accelerator pump or base gasket, Idle speed hunting or stalling

Fix: Quadrajet rebuild with correct jetting for 455 SD; replace fuel filter, inspect fuel pump pressure (5-7 psi spec), verify choke operation. Most survivors need complete carb overhaul plus fuel line inspection for leaks. 4-6 hours labor for proper rebuild and tuning.

Estimated cost: $600-1,100

Typical onset: 100,000-150,000 mi on original rings, or prematurely if poorly broken-in or overheated

Symptoms: Blue smoke on deceleration or startup, Oil consumption exceeding 1 quart per 500 miles, Loss of compression (below 140 psi in one or more cylinders), Reduced power and throttle response

Fix: If cylinder walls salvageable, hone and re-ring with modern moly rings (engine out, heads off, 25-35 hours). If glazing severe or taper exceeds .006", requires bore and oversized pistons. Many techs recommend full rebuild at this point given age and parts availability.

Estimated cost: $3,500-7,500

Typical onset: points require replacement every 10,000-12,000 mi; distributor bushing wear becomes issue after 80,000+ mi

Symptoms: Misfiring at high RPM or under load, Difficulty starting, inconsistent idle quality, Timing drifts and requires frequent adjustment, Distributor shaft visible side-play (worn bushings)

Fix: Convert to electronic ignition (Pertronix or similar) to eliminate points maintenance; if distributor bushings worn, rebuild or replace distributor. Electronic conversion: 1-2 hours. Distributor rebuild: 3-4 hours with proper shimming.

Estimated cost: $250-650