1971 AMC HORNET

Symptoms: Clunking when shifting between drive and reverse, Excessive drivetrain vibration at idle, Visible sag of transmission tailshaft

Fix: Rubber mounts deteriorate badly after 50 years regardless of mileage. Replacement requires lifting transmission slightly, 1.5-2 hours labor. Often both engine and trans mounts are done together since access is similar.

Estimated cost: $150-300

Typical onset: 80,000-150,000 mi

Symptoms: Oil pooling on garage floor behind engine, Oil coating bellhousing and transmission front, Gradual oil consumption without visible leaks elsewhere

Fix: The two-piece rear main seal design is notorious for weeping. Proper fix requires transmission removal, 6-8 hours labor. Many owners just monitor oil level and live with minor seepage unless transmission is already out for other work.

Estimated cost: $450-800

Symptoms: Red ATF puddles under vehicle, Transmission overheating, Low fluid level warnings or slipping gears, Visible rust perforation on steel cooler lines

Fix: Original steel lines rust through, especially where they route near the frame. Line replacement is 2-3 hours, but if you lose fluid while driving, transmission damage follows quickly. Upgrade to braided stainless lines recommended.

Estimated cost: $200-400

Symptoms: Hard starting after sitting, Stalling at idle when warm, Hesitation under acceleration, Fuel smell from evaporated varnish in tank

Fix: Ethanol fuel plus decades of sitting creates varnish buildup in tank, lines, and carburetor. Inline filter clogs quickly. Full cleaning involves tank removal and boiling/coating (4-6 hours), carburetor rebuild (2-3 hours), and new fuel lines. Filter replacement alone is 0.5 hours but temporary if system isn't cleaned.

Estimated cost: $400-900

Typical onset: 120,000-180,000 mi

Symptoms: Rattling from front of engine on cold start, Poor idle quality, Backfiring through carburetor, Timing drifts retarded despite distributor adjustment

Fix: AMC sixes are tough but chains do stretch. Replacement requires front cover removal, 4-5 hours labor. Smart to do water pump, front seal, and valve cover gasket while you're in there. Not an emergency but ignoring it risks jumped timing.

Estimated cost: $350-650

Symptoms: Visible rust perforation in driver's floor or rear seat area, Soft spots when pushing on floor with foot, Surface rust bubbling through undercoating on frame rails, Failed inspection due to structural corrosion

Fix: Hornets rust badly in the floor pans, particularly driver's side and rear torque box areas. Patch panels available but proper repair involves cutting out rust and welding in new metal, 8-15 hours depending on severity. Frame rail rust can be structural—walk away if advanced.

Estimated cost: $800-2,500