The TC Gemini refined everything Holden got right with the TX. Better trim, improved reliability, and subtle styling updates made it one of the most popular early Geminis — and today, one of the most restorable.
Engine & Drivetrain Restoration Checklist
Factory Engine
- 1.6L Isuzu G161Z OHV petrol
- Nikki downdraft carburettor
- 4-speed manual (most common)
- 3-speed automatic (less common)
Engine Parts to Inspect or Replace
- Full engine rebuild kit (pistons, rings, bearings)
- Timing chain & tensioner
- Oil pump
- Water pump & thermostat
- Radiator (TC units often clogged internally)
- Carburettor rebuild kit
- Fuel pump (mechanical)
- Engine mounts
- Ignition system (points, condenser, coil, leads)
Transmission, Clutch & Differential
Gearbox & Driveline Checklist
- Gearbox synchros (especially 2nd & 3rd)
- Input/output shaft seals
- Clutch kit (plate, pressure plate, release bearing)
- Clutch master & slave cylinders
- Tailshaft uni joints
- Differential bearings & seals
- Gear shifter bushes
- Transmission mount
Suspension & Steering Components
The TC uses front MacPherson struts and a live rear axle, similar to TX but with minor refinements.
Suspension Checklist
- Front strut inserts
- Coil springs (standard or mild drop)
- Upper strut mounts
- Lower control arm bushes
- Ball joints
- Tie rod ends
- Steering rack boots
- Rear trailing arm bushes
- Rear shocks
Brake System Restoration
Factory Setup
- Front disc brakes
- Rear drum brakes
Brake Parts Checklist
- Front rotors
- Calipers & rebuild kits
- Brake pads
- Rear drums, shoes & wheel cylinders
- Brake master cylinder
- Brake booster
- Rubber brake hoses
- Handbrake cables
Body Panels & Rust Repair (Very Important)
Rust is the biggest TC Gemini killer.
Known TC Gemini Rust Areas
- Front chassis rails
- Inner guards
- Battery tray
- Floor pans
- Sills & doglegs
- Rear quarter panels
- Boot floor
- Windscreen lower corners
Body Restoration Checklist
- Floor repair sections
- Sill repair panels
- Door seals
- Window rubbers
- Bonnet & boot seals
- Chrome bumpers
- TC-specific badges & emblems
Interior Restoration Parts
TC interiors improved over TX but are still fragile today.
Interior Checklist
- Seat foam & upholstery kits
- Door cards
- Dash pad (cracking is common)
- Carpet kits (moulded)
- Headliner
- Sunvisors
- Steering wheel restoration
- Interior clips & fasteners
Electrical & Lighting
Electrical Checklist
- Wiring loom inspection
- Alternator
- Starter motor
- Voltage regulator
- Battery cables & earth straps
- Fuse box refresh
- Headlights
- Tail light lenses
- Indicator lenses
- Dash bulbs & switches
Poor earthing causes most Gemini electrical issues.
Wheels, Tyres & Running Gear
Checklist
- Factory steel wheels or period alloys
- Correct hubcaps
- Wheel bearings (front & rear)
- Differential mounts
- Tyres in period-correct sizes