1977 PLYMOUTH TRAIL DUSTER

Typical onset: 80,000-120,000 mi

Symptoms: Rough idle and surging at startup, Rattling from front of engine on cold start, Loss of power and poor fuel economy, Backfiring through carburetor, Won't start or hard starting when severely worn

Fix: Replace timing chain, gears, and tensioner. Requires radiator removal on most setups. Good time to replace water pump, oil pump, and front seal. 6-8 hours labor for experienced tech, more if stuck bolts or frozen damper.

Estimated cost: $800-1,400

Symptoms: Visible rust perforation in driver/passenger floor pans, Rocker panels crumbling or missing entirely, Weak or flexing body structure when jacking, Carpet wet after rain or car wash, Exhaust fumes entering cabin

Fix: Requires cutting out rust and welding in patch panels or full floor pans. Rockers often need complete replacement. Structural integrity issue — not cosmetic. 12-20 hours labor depending on extent, plus metal fabrication skills required.

Estimated cost: $1,800-4,500

Typical onset: 60,000+ mi

Symptoms: High idle that won't come down, Stalling when coming to a stop, Black smoke and fuel smell from exhaust, Hesitation on acceleration, Poor fuel economy (under 10 mpg)

Fix: Rebuild kit addresses most issues, but throttle shafts wear oval in the body causing vacuum leaks that no rebuild fixes. Often needs complete replacement or professional re-bushing of shafts. 2-4 hours for rebuild, but many techs just swap a remanufactured unit.

Estimated cost: $300-650

Typical onset: 70,000-100,000 mi

Symptoms: Clunking over bumps from front end, Steering wander and poor return to center, Uneven tire wear on inside edges, Vehicle pulls to one side, Squeaking during turns

Fix: Lower control arm bushings deteriorate and tear. Requires pressing out old bushings and installing new ones, or swapping complete control arms. Also inspect upper bushings and ball joints while there. 4-5 hours labor for both sides including alignment.

Estimated cost: $500-850

Symptoms: Fuel gauge reads empty when tank is full, Gauge bounces erratically or sticks, Gauge reads full constantly regardless of fuel level

Fix: Sending unit float arm corrodes or rheostat wears out. Tank must be dropped to replace. Common on vehicles stored outdoors or with old ethanol fuel. 2-3 hours labor to drop tank, replace unit, and reinstall.

Estimated cost: $250-450

Typical onset: 60,000-90,000 mi

Symptoms: Clunking when engaging 4WD, Vibration during acceleration in 4WD, Grinding or squealing from front axle, Complete loss of drive to front wheels

Fix: Front axle U-joints see heavy stress and fail without regular greasing. Requires removing axle shafts and pressing out joints. If delayed, can damage axle shafts or yoke. 3-4 hours labor per side. Should replace both sides and all four joints when doing the work.

Estimated cost: $400-700

Typical onset: 80,000+ mi

Symptoms: Power steering fluid leak on frame rail below steering box, Groaning noise when turning at low speeds, Gradually worsening steering effort, Fluid level dropping in power steering reservoir

Fix: Sector shaft seal hardens and leaks. Can be replaced with box on vehicle but requires removing pitman arm and adjustment. Many techs pull the box for bench work. If internal wear is present, needs rebuild or replacement. 3-5 hours labor.

Estimated cost: $350-800