The 1964 Buick Skylark is a compact-for-the-era GM A-body with either the 225ci V6 or 300ci V8. The two-speed automatic transmissions and aging engine internals dominate the repair landscape—these are 60-year-old cars now, so expect comprehensive rebuilds rather than component swaps.
Two-Speed Automatic Transmission Failure (ST-300 / Dual-Path Turbine Drive)
Common · high severityTypical onset: Original units often fail between 80,000-120,000 mi, but many have been rebuilt multiple times by now
Symptoms: Slipping between gears or won't shift out of first, Whining or grinding under acceleration, Leaking fluid from cooler lines or pan seals, Harsh engagement into reverse
Fix: Full rebuild is standard—expect 12-16 hours labor. Hard parts (clutches, bands, seals, bushings) plus machine work. External cooler lines and mounts typically replaced simultaneously. Skilled ST-300 shops are scarce; some owners convert to TH350.
Estimated cost: $2,200-3,800
225ci V6 Odd-Fire Engine Vibration and Bearing Wear
Common · medium severityTypical onset: Manifests after 70,000 mi if original, but most survivors have been rebuilt
Symptoms: Persistent vibration at idle that smooths slightly under load, Low oil pressure hot (under 20 psi at idle), Knocking from lower end—main or rod bearings, Blue smoke on startup indicating worn rings
Fix: The odd-fire 225 wears mains and rods unevenly. Full teardown, mag-flux crank, bore/hone cylinders, new bearings, rings, timing set. Plan 20-24 hours labor. Many owners swap to a 300ci or later even-fire V6 instead of rebuilding the 225.
Estimated cost: $3,200-5,000
300ci V8 Crankshaft and Main Bearing Failure
Occasional · high severityTypical onset: 90,000-140,000 mi on original bottom end
Symptoms: Deep knocking that worsens with RPM, Metal shavings in oil or filter, Sudden loss of oil pressure, Engine seizes if bearing fragments block pickup
Fix: Crank removal, inspection, and grind/polish (if salvageable) or replacement. New mains, rod bearings, rear seal. Engine must come out. 18-22 hours labor. If crank is toast, sourcing a good core adds weeks and cost.
Estimated cost: $2,800-4,500
Transmission Oil Cooler Line Corrosion and Leaks
Common · medium severitySymptoms: Transmission fluid puddle under radiator area, Low fluid level leading to slipping or overheating, Rusty scale visible on steel cooler lines, Fluid weeping at crimped fittings
Fix: Replace steel lines with pre-bent reproductions or custom-bent stainless. 2-3 hours labor. Often done during transmission rebuild to prevent immediate re-failure. Cooler itself may need flushing or replacement if contaminated.
Estimated cost: $250-500
Engine and Transmission Mount Deterioration
Common · low severitySymptoms: Excessive engine rocking on acceleration or deceleration, Clunking when shifting into gear, Driveline vibration at highway speed, Visible cracking or separation of rubber from metal brackets
Fix: Replace all mounts—front engine, rear transmission, and side mounts. Rubber compounds fail after decades even with low miles. 3-4 hours labor total. Significantly improves drivability and reduces stress on exhaust and linkage.
Estimated cost: $400-700
Carburetor Flooding and Fuel System Varnish (Rochester 2GC/2GV)
Occasional · medium severitySymptoms: Hard starting when hot, floods easily, Fuel smell in cabin or garage, Rough idle, stumbling on acceleration, Black smoke from exhaust under load
Fix: Carburetor rebuild with all new gaskets, float, needle/seat, accelerator pump. Clean all passages. Fuel filter replacement mandatory. If sitting for years, tank may need cleaning or replacement. 4-6 hours for thorough carb service and fuel system cleaning.
Estimated cost: $350-650
Buy only if you have a trusted vintage GM mechanic or DIY skills—budget $3,000-5,000 for deferred engine/transmission work on any 'driver' example, more for neglected cars.
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.