1969 CHEVROLET BISCAYNE

Typical onset: 90,000-150,000 mi

Symptoms: Slipping on acceleration, especially 1-2 shift, Delayed engagement when shifting into Drive, Burnt transmission fluid smell, dark or metallic fluid, Clunking or banging into gear from Park

Fix: Full rebuild required—expect 8-12 hours labor for R&R and rebuild. Powerglides are simpler (fewer clutches) but parts availability varies. TH350s more common and easier to source. Includes new clutches, bands, seals, filter, and torque converter inspection. Often find worn forward clutch drum or sun shell.

Estimated cost: $1,800-3,200

Typical onset: 120,000-180,000 mi

Symptoms: Blue smoke on startup or deceleration, Excessive oil consumption—quart every 500-800 miles, Low compression readings on multiple cylinders, Fouled spark plugs, especially on decel

Fix: Ring job requires minimum 14-18 hours—engine out, complete disassembly, hone cylinders, new rings, bearings, gaskets, timing chain. If bores are scored or tapered beyond .010, needs .030 overbore and pistons, adding cost. Many shops go straight to short block swap (12-16 hours) rather than risk machine work on tired blocks.

Estimated cost: $2,500-4,800

Symptoms: Visible rust-through on frame rails behind front wheels, Body mounts crumbling—rubber separates from metal, Doors misaligned or hard to close as body sags, Floor pan soft spots or holes near rocker panels

Fix: Northern/rust-belt cars suffer worst. Body mounts alone: 6-8 hours to jack body, replace all 12-14 mounts. Frame rust repair depends on severity—surface scale vs. structural holes. Welding in frame sections: 12-20 hours plus metal, only practical if rest of car is solid. Many find rear frame kick-ups rotted where rear springs mount.

Estimated cost: $800-1,400 (mounts only), $3,000-6,000+ (frame welding)

Symptoms: Hard starting when cold, requires excessive cranking, Stumbling or hesitation at idle or light throttle, Stalling in traffic or when warm, Black smoke or extreme richness—choke not opening

Fix: Cars sitting for months or years develop varnish in Rochester or Holley carbs. Complete rebuild: 3-4 hours including tank drop, fuel line flush, new filter, pump check, and carb disassembly. Often find stuck floats, clogged jets, corroded choke pulloffs. Ethanol fuel accelerates this. Tank may need boiling out if heavily contaminated.

Estimated cost: $450-850

Typical onset: 80,000-130,000 mi

Symptoms: Gear oil dripping from axle tube ends onto brakes, Rear brake contamination causing pull or reduced stopping, Rumbling or grinding noise from rear, speed-related, Differential whine on deceleration

Fix: Common on 10- and 12-bolt rears. Axle seal replacement: 2-3 hours per side, includes pulling drums, axles, and pressing new seals. If bearings are grooved, add bearing and possibly axle replacement—bearings pressed on shaft. Many find axles rusted into tubes on high-mileage cars, requiring penetrant and heat. If diff itself is noisy, full rebuild: 6-10 hours.

Estimated cost: $350-650 (seals/bearings per side), $1,200-2,200 (differential rebuild)

Symptoms: Misfiring at highway speeds or under load, Erratic idle or sudden RPM drop, Hard starting despite good fuel delivery, Points burning or excessive gap change in under 5,000 miles

Fix: Points-type ignition requires service every 10,000-12,000 miles—many owners neglect this. Worn distributor bushings cause point gap variation and timing scatter. Bushing replacement: 2-3 hours with dist removal, or swap to HEI or Pertronix electronic conversion (1.5 hours)—eliminates problem permanently. Check condenser, cap, rotor, plug wires while in there.

Estimated cost: $180-350 (tune with bushing), $250-450 (electronic conversion)