The 1968 Biscayne is Chevy's bare-bones full-size workhorse built on the sturdy B-body platform. Most survivors have seen hard lives as fleet vehicles or work trucks, so expect wear consistent with high original mileage and deferred maintenance rather than inherent design flaws.
Powerglide/TH350 Transmission Failures
Common · high severityTypical onset: 90,000-150,000 mi
Symptoms: Slipping between gears especially 1-2 shift, Delayed engagement when shifting to Drive or Reverse, Burnt transmission fluid smell and dark discoloration, Loss of forward gears but reverse still works
Fix: Full rebuild required in most cases - these units were not over-built and fleet service kills them. Expect 8-12 hours labor for R&R and rebuild. Add transmission cooler if not present to prevent repeat failure.
Estimated cost: $1,800-3,200
Engine Bottom-End Failures (All V8s)
Occasional · high severityTypical onset: 120,000-180,000 mi
Symptoms: Heavy knocking from lower engine that worsens under load, Loss of oil pressure at idle, Metal shavings in oil during change, Visible smoke from breather or excessive blowby
Fix: Rod bearings and main bearings wear out from age and inadequate oil changes. Most cost-effective fix is short block replacement or full rebuild with crank turning. 18-24 hours labor for engine R&R plus machine work.
Estimated cost: $3,500-6,500
Deteriorated Frame and Body Mounts
Common · medium severitySymptoms: Clunking over bumps from body shifting on frame, Doors suddenly misaligning or becoming hard to close, Visible gaps between body and frame that change when driving, Cracked rubber mounts or completely separated metal plates
Fix: These rubber biscuits dry rot after 50+ years regardless of mileage. All 12-14 mounts should be replaced as a set. Requires supporting body while swapping mounts. 6-8 hours labor.
Estimated cost: $600-1,200
Worn Steering Box and Linkage
Common · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Excessive play in steering wheel (more than 2 inches), Wandering on highway requiring constant correction, Clunking when turning wheel back and forth, Uneven tire wear on front
Fix: Manual steering boxes wear internally and idler arms wear out. Center link and tie rod ends also common culprits. Plan to replace steering box ($400-600 rebuilt) plus all linkage components. 4-6 hours labor plus alignment.
Estimated cost: $800-1,400
Fuel System Varnish and Clogging
Common · medium severitySymptoms: Hard starting after sitting overnight, Hesitation or stumbling during acceleration, Stalling at idle after warmup, Fuel smell from carb overflow or tank vent
Fix: Old ethanol fuel leaves varnish throughout. Requires carburetor rebuild, new fuel filter, fuel pump testing, and often gas tank cleaning or replacement. Fuel lines may be crusty inside. 3-5 hours depending on tank condition.
Estimated cost: $400-900
Rear End Axle Seal and Bearing Leaks
Occasional · low severityTypical onset: 100,000+ mi
Symptoms: Gear oil on inside of rear wheels or brake drums, Whining or howling from rear end during acceleration, Clunking when changing from forward to reverse, Low differential fluid level
Fix: Axle seals dry out and bearings wear from contamination. Requires pulling axles, replacing seals and bearings. If brake contamination occurred, shoes need replacement too. 3-4 hours per side.
Estimated cost: $400-800
Buy one if you find a solid survivor with documented maintenance - parts are cheap and plentiful, but most examples have been used hard and need comprehensive mechanical freshening at this age.
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.