1955 CADILLAC FLEETWOOD SIXTY SPECIAL

Typical onset: 80,000-150,000 mi or unknown mileage with deferred maintenance

Symptoms: Deep knocking from crankcase especially when cold, Metallic rattling at idle that worsens with RPM, Sudden catastrophic loss of oil pressure, Metal shavings in oil filter and pan

Fix: Complete teardown required. If caught early with bearing wear, machine crank journals, install oversize bearings (16-20 hours labor). If spun bearings damaged crank, you're looking at crank grinding or replacement, full lower-end rebuild with new pistons/rings while it's apart (30-40 hours labor). Most survivors need this work by now given age.

Estimated cost: $4,500-8,500

Typical onset: Any mileage on original gaskets after 65+ years

Symptoms: White smoke from exhaust on startup, Coolant loss with no visible leaks, Rough idle or misfire on adjacent cylinders, Combustion gases in cooling system, Milky oil if severe

Fix: Pull both heads, resurface if warped, install modern composite gaskets with proper torque sequence. While heads are off, mandatory valve job and guide inspection (18-24 hours labor). Given age, most need this plus hardened exhaust seats for unleaded fuel.

Estimated cost: $2,800-4,200

Typical onset: 60,000-100,000 mi or any mileage with old fluid

Symptoms: Delayed engagement into Drive or Reverse (more than 2-3 seconds), Slipping between 2nd and 3rd gear under load, No 3rd or 4th gear - stays in 2nd, Whining or grinding noises in gear, Burnt transmission fluid smell

Fix: Four-speed Hydra-Matic requires full rebuild - clutch packs, bands, seals, bushings. These are rebuildable but require specialized knowledge of this early design. Complete R&R and rebuild runs 20-28 hours. Parts availability is decent through specialty suppliers.

Estimated cost: $3,200-5,500

Symptoms: Transmission fluid dripping or spraying from front of car, Rapid transmission fluid loss, Transmission overheating after highway driving, Fluid visible on radiator core support

Fix: Steel lines rust through at mounting points and radiator connections. Replace all cooler lines, not just the leaking section - the rest will fail soon (3-4 hours labor). Upgrade to braided stainless if possible for longevity.

Estimated cost: $400-700

Symptoms: Stalling after 15-20 minutes of driving when hot, Hesitation and stumbling under acceleration, Hard starting after sitting, Fuel starvation symptoms at highway speed, Rough idle that clears up temporarily after restart

Fix: Old fuel leaves varnish throughout system. Drop tank, clean or replace, new fuel pump, rebuild carburetor, replace all rubber fuel lines, new filter (8-12 hours labor). Tank replacement often necessary due to internal rust. Cannot be fixed piecemeal - entire system needs attention.

Estimated cost: $1,200-2,200

Symptoms: Clunk when shifting from Park to Drive/Reverse, Excessive vibration at idle in gear, Transmission appears to sag visibly, Driveline vibration at certain speeds

Fix: Rubber mounts deteriorate with age even on low-mileage cars. Replace transmission mount and inspect engine mounts simultaneously (2-3 hours labor). Relatively straightforward job but requires proper jacking and support.

Estimated cost: $300-550