1970 DODGE CORONET

Typical onset: 80,000+ mi or unknown history

Symptoms: Rough idle with retarded cam timing, Hard starting when hot, Metallic rattling from front of engine at startup, Loss of power, misfiring under load

Fix: Replace timing chain, gears, and tensioner as a set. The nylon cam gear teeth disintegrate over time. Requires front cover removal, harmonic balancer puller, new gaskets, and timing degree check. 4-6 hours labor for a 318/383, add 1-2 hours for bigger blocks due to accessory crowding.

Estimated cost: $600-1,200

Symptoms: Hard hot restarts, engine floods after sitting, Black smoke, fuel smell in engine bay, Fuel dripping from carb base or bowls, Hesitation, stumble off idle when hot

Fix: Old ethanol-degraded gaskets and dried-out needle/seat assemblies leak. Heat soak from modern fuel causes vapor lock. Full carb rebuild with ethanol-compatible kit, or swap to electric fuel pump with return line. 2-4 hours for rebuild and tuning.

Estimated cost: $300-700

Symptoms: Front end sitting noticeably low, Uneven ride height side-to-side, Clunking from front crossmember over bumps, Torsion bar socket rust-through in lower control arm

Fix: Torsion bars themselves rarely fail, but the adjusting bolts seize and the rear anchors corrode in the crossmember. Worst cases need crossmember repair or replacement. Sag is fixed by cranking adjusters or replacing bars with HD units. Bushing and ball joint refresh while you're in there. 6-10 hours for full front suspension overhaul.

Estimated cost: $800-2,000

Typical onset: 60,000+ mi or after long storage

Symptoms: Oil dripping from bellhousing area or pan rails, Puddles under car after sitting overnight, Oil consumption without visible exhaust smoke

Fix: The rope-style rear main seal hardens and shrinks with age. Oil pan gaskets are cork and disintegrate. Rear main requires transmission removal (5-7 hours for auto, 4-6 for manual). Oil pan is easier but crossmember may need to be dropped. Often both done together.

Estimated cost: $700-1,400

Symptoms: Transmission won't downshift for passing, Sluggish acceleration, stays in high gear too long, Harsh or late upshifts

Fix: The external kickdown rod from carb to trans gets bent, seized, or disconnected during engine work. Without proper adjustment, line pressure drops and clutches slip prematurely. Adjustment is critical—too tight causes harsh shifts, too loose burns clutches. 0.5-1 hour for linkage service and adjustment.

Estimated cost: $80-200

Typical onset: 70,000+ mi

Symptoms: Excessive play at steering wheel (more than 2 inches of slop), Wandering on highway, constant correction needed, Clunking felt through steering column over bumps

Fix: Manual steering boxes wear internally and develop lash. Power steering boxes leak and lose adjustment. Pitman and idler arms wear out their tapered shafts. Full steering rebuild includes box rebuild/exchange, pitman, idler, tie rod ends, and alignment. 5-8 hours total.

Estimated cost: $600-1,300

Symptoms: Overheating in traffic or on highway, Coolant leaking from radiator seams or tubes, Sweet smell in cabin, fogged windshield, wet passenger floor

Fix: Original copper/brass radiators corrode through after decades. Heater cores fail internally and leak into the cabin—requires full dash pad removal on non-AC cars, entire evaporator housing on AC cars. Radiator swap is 2-3 hours. Heater core is 8-12 hours due to dash disassembly.

Estimated cost: $400-800 radiator, $800-1,800 heater core