1975 PONTIAC LEMANS

Typical onset: 80,000-120,000 mi

Symptoms: delayed engagement when shifting into gear, slipping between 1-2 or 2-3 shifts under load, burnt transmission fluid smell, no reverse or stuck in one gear

Fix: Full rebuild required — clutch packs, bands, seals, filter, fluid, torque converter inspection. Budget 12-16 hours labor for removal, rebuild, reinstall. TH400s behind 455s fail earlier due to torque abuse. Cooler lines rust through and starve fluid.

Estimated cost: $1,800-2,800

Symptoms: stumbling on acceleration, black smoke from exhaust, hesitation or flooding when cold, rough idle that smooths out at higher RPM, fuel leaking from accelerator pump

Fix: Ethanol fuel deteriorates rubber components, clogs jets, warps float. Full rebuild kit with non-ethanol-compatible parts runs 4-6 hours including removal, disassembly, cleaning, reassembly, tuning. Many shops won't touch them anymore — carb specialists charge premium.

Estimated cost: $450-850

Typical onset: 60,000-90,000 mi

Symptoms: knocking from lower engine block at idle, oil pressure drops below 10 psi hot, metallic rattling that worsens with RPM, oil contamination with metal flakes

Fix: Odd-fire V6 design causes harmonic imbalance that hammers main and rod bearings. Requires engine removal, full teardown, crank inspection/machining, bearing replacement, possibly line boring. 20-28 hours labor. Many techs recommend swapping in a 350 V8 instead for similar cost.

Estimated cost: $2,200-3,800

Symptoms: body creaking over bumps, visible rust perforation on frame rails behind front wheels, doors misalign or won't latch properly, floor pan rust-through in footwells, sagging body at rear quarters

Fix: A-body frames rust from inside out — especially in salt states. Body mounts (rubber biscuits) rot and crush, allowing body flex. Proper fix requires body-off restoration with frame sandblasting and POR-15, new mounts. Patch jobs never last. 30-50 hours labor depending on extent. Parts are cheap, labor is brutal.

Estimated cost: $3,500-7,000

Typical onset: 70,000-110,000 mi

Symptoms: loss of power especially at highway speeds, engine overheating under load, rotten egg smell from exhaust, backfiring through carburetor, cat glowing red-hot after hard driving

Fix: First-year cats (1975) are primitive and clog from rich-running carbs. Backpressure test confirms. Remove cat, install test pipe or modern high-flow cat. 2-3 hours labor. Legality varies by state — some allow pre-1976 exemption. Often reveals other exhaust rot that needs welding.

Estimated cost: $280-600

Symptoms: fuel gauge reads empty when tank is full or stuck at one position, fuel smell near tank, rust particles clogging fuel filter repeatedly, hard starting after sitting, visible rust staining on tank exterior

Fix: Ethanol corrodes original steel tanks and zinc sending units. Tank removal requires dropping rear axle or cutting floor. Budget 4-6 hours. New reproduction tanks run $200-300, sending unit another $80. Fuel lines often need replacement simultaneously due to rust. Flush entire system after tank swap.

Estimated cost: $550-950

Typical onset: 90,000-140,000 mi

Symptoms: 3-4 inches of steering wheel play before wheels respond, constant correction needed to stay in lane, clunking from steering column over bumps, groaning when turning at low speed

Fix: Saginaw manual steering boxes wear internally — sector shaft and worm gear develop slop. Adjustment helps temporarily but rebuild or replacement needed. Rebuilt boxes available $200-300 core exchange. 3-5 hours labor including alignment. Power steering boxes leak at sector shaft seal — less play but messy.

Estimated cost: $450-750