1972 GMC K1500

Typical onset: 80,000-150,000 mi

Symptoms: Rattling noise on cold start that disappears after oil pressure builds, Rough idle and hesitation, Check timing and find it's retarded several degrees, Hard starting when warm

Fix: Replace timing chain, gears, and tensioner. Original nylon-toothed cam gears deteriorate and nylon teeth break off. Requires front cover removal. 4-6 hours labor for experienced tech. Always replace oil pump and front seal while you're in there.

Estimated cost: $600-1,200

Symptoms: Visible rust perforation in cab corners and rockers, Spongy or rusted-through floor pans especially driver side, Bed floor rust near stake pockets and wheel wells, Rust jacking at cab mounts

Fix: Rust repair ranges from patch panels to full floor replacement. Cab corners and rockers are available as reproduction panels. Floor pans require cutting out old metal and welding in new. 12-40 hours depending on extent. Worst cases need professional restoration shop.

Estimated cost: $1,500-8,000

Symptoms: Black smoke and flooding from worn needle/seat, Hesitation and stumble on acceleration, Difficult hot starts, Fuel leaking from accelerator pump or base gasket, Poor fuel economy

Fix: Rebuild with quality kit addressing all wear points, or replace with remanufactured unit. DIY rebuild takes 3-5 hours if you know Quadrajets; first-timers double that. Consider electric choke conversion if manual choke is sticking. Ethanol fuel accelerates deterioration of original rubber parts.

Estimated cost: $150-450

Typical onset: 60,000-100,000 mi

Symptoms: Clicking or popping during turns in 4WD, Vibration that increases with speed, Growling noise from front wheels, Excessive play in front wheel when checking for wear

Fix: Dana 44 front axle uses u-joints in the axle shafts that wear from lack of grease and water intrusion. Wheel bearings also fail from age and contamination. Replace u-joints and bearings together. 4-6 hours per side including hub service. Requires special tools for inner axle shaft removal.

Estimated cost: $800-1,400

Typical onset: 70,000-120,000 mi

Symptoms: Excessive play in steering wheel before wheels respond, Wandering on highway requiring constant correction, Clunking over bumps, Uneven tire wear, Failed inspection due to excessive play

Fix: Original steering components wear out from age and use. Idler arm bushings collapse, tie rod ends loosen, Pitman arm develops play. Replace entire linkage as a system for best results. 3-5 hours labor plus alignment. Don't cheap out on parts—use quality Moog or equivalent.

Estimated cost: $600-1,000

Symptoms: Soft or spongy brake pedal that doesn't firm up after bleeding, Brake fluid leak at master cylinder, Corroded brake lines at frame rail bends and rear axle, Rear brakes locking up prematurely from stuck proportioning valve

Fix: Single-reservoir master cylinders were still common in '72 and fail internally. Steel brake lines rust through at bends and clips. Replace master cylinder, inspect all hard lines, replace any with surface rust. Consider upgrading to dual-reservoir master. 4-8 hours depending on line replacement extent.

Estimated cost: $500-1,200

Typical onset: 80,000+ mi

Symptoms: Gear oil dripping from front driveshaft connection, Low transfer case fluid level, Whining noise from transfer case under load

Fix: Full-time 4WD NP203 transfer case front output seal leaks from age and worn companion flange. Requires removing front driveshaft and companion flange. 2-3 hours labor. Check fluid level regularly—running low damages chain and bearings.

Estimated cost: $250-450