The 1968 Firebird is a first-generation F-body with solid bones but 55+ years of age showing. Expect transmission issues, engine sealing problems, and typical GM rust/electrical gremlins from the era.
Powerglide/TH350 Transmission Failure
Common · high severityTypical onset: 80,000-120,000 mi
Symptoms: Slipping between gears especially 1-2 shift, Delayed engagement when shifting to Drive, Burnt transmission fluid smell, No movement in any gear
Fix: Full rebuild required in most cases — expect 12-16 hours labor for removal, rebuild, and reinstallation. Powerglide simpler than TH350 but parts getting scarce. Many originals have never been rebuilt and are living on borrowed time.
Estimated cost: $2,200-3,800
Rear Main Seal and Oil Pan Gasket Leaks
Common · medium severityTypical onset: 60,000+ mi
Symptoms: Oil pooling under engine after sitting, Oil spots on driveway consistently in same location, Low oil level between changes, Oil coating bellhousing and starter
Fix: Rear main seal requires transmission removal — 8-10 hours labor. Oil pan gasket can be done in 4-5 hours but cork gaskets from this era harden and leak. Often both done simultaneously since trans is already out.
Estimated cost: $800-1,600
Carburetor Issues (Rochester 2GC/Quadrajet)
Common · medium severitySymptoms: Hard starting when cold, Rough idle and stalling at stop lights, Black smoke from exhaust under acceleration, Fuel leaking from carb base or accelerator pump
Fix: Most original carbs need full rebuild with modern ethanol-resistant gaskets and seals — 3-4 hours labor. Accelerator pump diaphragms fail frequently. Many have been replaced with Edelbrocks by now, which reduces issues.
Estimated cost: $450-900
Floor Pan and Torque Box Rust
Common · high severitySymptoms: Visible rust holes in driver/passenger floor, Soft or spongy floor when pressed, Water entering cabin during rain, Cracking sound from rear frame rails over bumps
Fix: Floor pans and torque boxes rust through from road salt and trapped moisture. Proper fix requires cutting out old metal and welding in replacement panels — 20-30 hours labor depending on extent. Structural safety issue that affects resale.
Estimated cost: $2,500-5,500
Distributor Gear and Timing Chain Wear
Occasional · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Timing keeps drifting out of spec, Rattling noise from front of engine on startup, Loss of power and misfiring, Metal shavings in oil
Fix: Original nylon-tipped timing gears disintegrate and chains stretch. Distributor gear wears on shaft. Timing set replacement is 6-8 hours with front cover removal. Distributor rebuild adds 2-3 hours. Do both together.
Estimated cost: $900-1,600
Fuel Tank and Sending Unit Corrosion
Occasional · medium severitySymptoms: Fuel gauge reading erratic or stuck, Fuel smell around rear of car, Rust particles clogging fuel filter repeatedly, Tank visibly rusted when inspected
Fix: Steel tanks rust from inside out, especially with ethanol fuel. Sending units corrode and fail. Tank removal is 3-4 hours, replacement or professional cleaning/sealing adds cost. New reproduction tanks widely available.
Estimated cost: $650-1,200
Worn Suspension Bushings and Ball Joints
Common · medium severityTypical onset: 50,000-80,000 mi
Symptoms: Clunking over bumps from front end, Wandering steering and poor tracking, Uneven tire wear especially inside edges, Steering wheel off-center after hitting bumps
Fix: Control arm bushings, ball joints, and idler arm wear out. Originals are rubber and deteriorate. Full front-end rebuild with alignment is 8-10 hours. Polyurethane upgrades available but harsher ride.
Estimated cost: $1,200-2,000
Buy one if you're handy and it's rust-free — mechanicals are straightforward but corrosion is the real budget killer on these.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.