1968 CHEVROLET CAPRICE

Symptoms: Burnt transmission fluid smell, Slipping or delayed engagement, especially when hot, Fluid leaks at cooler lines or radiator connections, Brown fluid in radiator if internal cooler fails

Fix: Replace transmission oil cooler lines (often rusted through at fittings), flush cooler, replace fluid and filter. If internal radiator cooler fails, contamination requires full transmission rebuild. Cooler line replacement: 1.5-2 hours. Full rebuild with contamination: 12-16 hours.

Estimated cost: $300-600 for lines and service, $2,200-3,800 for rebuild

Symptoms: Clunking on acceleration or deceleration, Transmission tail shaft visible sag when inspected, Vibration through floor at idle in gear, Harsh gear changes

Fix: Rubber mount deteriorates with age and heat. Requires trans support, remove crossmember, replace mount. Often done with U-joint service. 1-1.5 hours labor.

Estimated cost: $150-280

Typical onset: 80,000-150,000 mi

Symptoms: Deep knocking from bottom of engine, worse under load, Low oil pressure at idle when warm, Metallic debris in oil pan, Sudden catastrophic failure if ignored

Fix: Main bearings or rod bearings worn beyond spec, often from years of low oil pressure or infrequent changes. Requires engine teardown, crank inspection/machining, new bearings, often new oil pump. If crank needs grinding: 18-24 hours. Many owners opt for full rebuild at this point since engine is apart. Machine work adds cost.

Estimated cost: $2,800-4,500 for in-chassis bearing replacement with crank work, $4,500-7,500 for full rebuild

Typical onset: 60,000-100,000 mi

Symptoms: Blue smoke on startup or deceleration, Oil consumption 1 quart per 500-800 miles, Fouled spark plugs, Rough idle when cold

Fix: Valve seals harden with age, guides wear oval. Complete valve job includes head removal, new guides/seals, valve grinding, spring inspection. 12-16 hours for both heads. Can sometimes get by with seal replacement only (heads on car) for 6-8 hours if guides are acceptable.

Estimated cost: $1,200-2,400 for seal replacement, $2,000-3,500 for complete valve job

Symptoms: Hard starting after sitting, Stumbling or dying at idle, Loss of power under load, Fuel starvation symptoms

Fix: Old fuel varnishes lines, clogs inline filter, gums up carburetor. Replace fuel filter (often neglected), clean or rebuild carb, inspect steel lines for internal rust. Modern ethanol fuel accelerates this. Filter change: 0.3 hours. Carb rebuild: 2-3 hours.

Estimated cost: $25-60 for filter, $350-650 for carburetor rebuild with kit

Typical onset: 100,000-180,000 mi

Symptoms: Excessive crankcase pressure, oil filler cap pops off, Heavy blue smoke under acceleration, Poor compression across multiple cylinders, Oil consumption over 1 quart per 300 miles

Fix: Rings lose tension, bores wear tapered or out-of-round. Requires full teardown, bore/hone, new pistons or rings, bearings while you're in there. 20-28 hours for complete job. Most techs recommend full rebuild at this point rather than ring-only job.

Estimated cost: $3,500-6,000 depending on machine work and parts quality