The 1968 Plymouth Belvedere is a robust B-body platform built during Chrysler's golden era of durability, sharing underpinnings with Road Runners and Chargers. Most issues stem from age-related deterioration rather than fundamental design flaws, though the LA-series small blocks and torsion bar suspension have predictable weak points.
Timing Chain Stretch and Gear Wear (V8 engines)
Common · medium severityTypical onset: 80,000-150,000 mi
Symptoms: Rattling noise from front of engine on cold starts that disappears when warm, Rough idle and hesitation, Backfiring through carburetor, Check timing and it's retarded 8-12 degrees from spec
Fix: Chain stretches on high-mileage engines, especially 318s and 273s. Requires timing cover removal, new chain/gear set, and front seal replacement while you're in there. Budget 4-6 hours labor for a straightforward job, more if you hit seized bolts or need to pull the radiator. Use a double-roller timing set, not the factory single-roller.
Estimated cost: $400-800
Torsion Bar Anchor Corrosion and Lower Control Arm Failure
Common · high severitySymptoms: Clunking over bumps from front end, Uneven ride height side-to-side, Visible rust perforation in rear torsion bar anchor crossmember, Wandering steering and loose feel, Lower ball joint boots torn or missing
Fix: The rear torsion bar crossmember rusts from the inside out, especially in salt states. Lower control arm bushings get sloppy and ball joints wear. A proper fix means cutting out and welding new anchor sections (3-4 hours fabrication plus alignment), or bolting in aftermarket reinforcement kits. Add control arm bushings, ball joints, and alignment. This cascades into a full front-end rebuild.
Estimated cost: $1,200-2,800
Single-Reservoir Master Cylinder Failure
Occasional · high severitySymptoms: Brake pedal slowly sinking to floor when stopped, Uneven braking or pull to one side, Fluid weeping from master cylinder rear seal, Complete brake failure with no warning
Fix: Factory single-reservoir master cylinders have no redundancy—one seal fails and you lose all braking. Originality purists rebuild them, but the smart move is converting to a dual-reservoir setup from a later A-body or aftermarket. Requires different pushrod and some brake line modifications. Budget 3-4 hours for the conversion including bleeding and testing.
Estimated cost: $300-600
Floor Pan and Trunk Rust-Through
Common · medium severitySymptoms: Visible holes in driver/passenger floor pans, Trunk floor perforated near wheelwells, Rear frame rail rust at spring mount points, Soft or spongy metal when you poke around drain plug areas
Fix: B-bodies rust in predictable spots: floor pans under carpet, trunk extensions, and lower quarters behind wheels. Patch panels are available but proper repair means cutting out rust and welding in new metal. Front floors alone are 8-12 hours if you're doing it right with full seam sealer and undercoating. Quarter patches add another 6-8 hours per side. Most shops won't touch it—you need a specialist.
Estimated cost: $2,000-5,000
Carburetor Float Bowl Leaking and Accelerator Pump Failure
Occasional · low severitySymptoms: Gas smell in garage after sitting, Hard starting when hot, Stumble or flat spot on acceleration, Fuel dripping from carburetor base or sight plugs, Black smoke on throttle tip-in
Fix: Carter AVS and Holley 2bbl carbs on these cars suffer from ethanol deterioration of gaskets and accelerator pump diaphragms. Rebuild kits run $40-80 and the job is 2-3 hours for someone familiar with the specific carburetor. Many shops just slap on a new Edelbrock instead for reliability. Original-correct rebuilds cost more because you need carburetor-specific knowledge that's disappearing.
Estimated cost: $200-500
Generator to Alternator Conversion Neglect
Occasional · low severitySymptoms: Dim lights at idle, Battery constantly needs charging, Ammeter shows discharge at idle with accessories on, Radio cuts out when brake lights applied
Fix: Many '68s still have original generators that can't keep up with modern demands (electric fans, stereos, phone chargers). Conversion to alternator is straightforward—later Mopar alternator bolts on, needs different pulley and wiring harness modifications. Figure 2-3 hours including proper voltage regulator relocation and wiring. Generators can be rebuilt but parts are expensive and output is still marginal.
Estimated cost: $300-600
Manual Steering Box Wear and Play
Occasional · medium severityTypical onset: 100,000+ mi
Symptoms: Excessive play at center—more than 2 inches at wheel rim, Wandering on highway requiring constant correction, Clunking felt through steering wheel over bumps, Binding when turning lock-to-lock
Fix: The manual steering boxes can be adjusted to take up slack but worn sector shaft bushings eventually cause slop that adjustment won't fix. Rebuilds are possible (4-5 hours R&R and rebuild) but finding someone who still does quality steering box work is tough. Many swap to later power steering—budget a weekend and $800-1,200 for used power box, pump, hoses, and bracket fabrication.
Estimated cost: $400-1,200
Absolutely buy one if you find a rust-free example with documented maintenance—mechanically simple and tough as nails, but avoid anything with serious body rust unless you're prepared for a full restoration.
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.