1973 AMC JAVELIN

Typical onset: 80,000-120,000 mi

Symptoms: Delayed engagement from Park to Drive, Slipping between 2nd and 3rd gear under load, Burnt transmission fluid smell and dark discoloration, Harsh downshifts or refusal to downshift

Fix: Complete transmission rebuild required, typically 12-16 hours labor. The Torque Command units behind the 360/401 especially suffer from inadequate cooling and clutch pack wear. Most need hard parts replaced including planetary gears and thrust washers.

Estimated cost: $2,200-3,800

Typical onset: 70,000-110,000 mi

Symptoms: White smoke from exhaust on cold start, Coolant loss with no visible leaks, Milky oil on dipstick or oil cap, Overheating under load or in traffic, Rough idle with occasional misfire

Fix: Head gasket replacement on both banks, 14-18 hours labor. AMC V8s are prone to head gasket failure due to thin deck surfaces and inadequate clamping force. Heads should be checked for warpage and resurfaced. Often find cracked heads on 401s that ran hot.

Estimated cost: $1,800-2,900

Typical onset: 100,000-140,000 mi

Symptoms: Excessive blue smoke on acceleration, Oil consumption over 1 quart per 500 miles, Low compression readings across multiple cylinders, Hard starting when engine is hot, Loss of power particularly on highway

Fix: Full engine rebuild with bore/hone, new pistons, rings, bearings. 25-35 hours labor for removal, rebuild, and reinstallation. AMC cast-iron blocks are generally sound but ring lands wear due to poor oil control and heat cycling. 401s particularly prone due to thin cylinder walls.

Estimated cost: $4,500-7,500

Typical onset: 60,000-90,000 mi

Symptoms: Clunk when shifting from Park to Drive or Reverse, Vibration through floorboard at idle in gear, Visible sagging of transmission tailshaft, Shifter feels loose or imprecise

Fix: Replace transmission mount and crossmember bushings, 1.5-2.5 hours labor. The rubber mounts compress and separate under the weight of the Torque Command transmission, especially with V8 torque. Often find the crossmember cracked as well on high-mileage examples.

Estimated cost: $180-350

Symptoms: Hard starting after sitting for days, Rough idle that smooths out after warmup, Hesitation or stumble on acceleration, Flooding with fuel smell in cabin, Stalling at stop signs when hot

Fix: Carburetor rebuild and fuel system cleaning, 3-5 hours labor. The Motorcraft 2100 (304) and Carter AFB/AVS (360/401) carburetors gum up from modern ethanol fuel. Accelerator pump circuits clog, float needles stick. In-tank sock filters collapse. Complete fuel filter replacement and carb rebuild needed.

Estimated cost: $450-800

Typical onset: 90,000-130,000 mi

Symptoms: Metallic knocking that changes with clutch engagement (manual), Excessive crankshaft endplay felt through vibration, Clutch pedal pulsation (manual transmission), Oil pressure drop at idle

Fix: Crankshaft removal and thrust bearing replacement, 18-24 hours labor including engine removal on most examples. AMC V8s use a rear thrust bearing that wears from clutch abuse or automatic converter ballooning. Requires complete disassembly, crank polishing, and new bearings throughout.

Estimated cost: $3,200-5,000