The VB, VC and VH Commodore represent an important chapter in Australian motoring history. Introduced in 1978, the VB Commodore marked Holden’s transition from the large Kingswood platform to a more modern, European-inspired design based on the Opel Rekord and Senator. The VC followed in 1980, while the VH arrived in 1981 and became one of Holden’s most successful early Commodore models.
Today, these first-generation Commodores are highly sought after by collectors, restorers and enthusiasts. However, one issue continues to affect almost every surviving example: rust.
Despite improvements in manufacturing and corrosion protection compared with earlier Holdens, VB, VC and VH Commodores are now more than 40 years old. Water traps, poor drainage, damaged paint and decades of Australian conditions have allowed rust to become a major concern.
In many cases, rust damage is far more serious than engine, transmission or suspension problems because structural repairs can be extremely expensive and time-consuming.
Why VB-VH Commodores Rust
Although more modern than previous Holdens, early Commodores still suffered from several rust-prone areas.
Common Causes
- Water retention
- Blocked drain holes
- Damaged paint
- Moisture trapped in seams
- Poor previous repairs
- Coastal environments
Many vehicles now have multiple rust issues developing simultaneously.
Front Windscreen Rust
One of the most common rust areas on VB, VC and VH Commodores is around the windscreen.
Symptoms
- Bubbling paint
- Rust stains
- Water leaks
- Visible corrosion under rubber seals
Why It Happens
Moisture becomes trapped beneath the windscreen rubber and slowly attacks the metal.
In severe cases, rust can spread into the A-pillars.
Rear Windscreen Rust
The rear window opening is equally susceptible.
Common Symptoms
- Water leaks into boot
- Rust bubbles around glass
- Damp carpet
Inspection Tips
Carefully inspect beneath the rubber seal and inside the boot area.
Many vehicles hide significant rust beneath apparently good paint.
Plenum Chamber Rust
The plenum chamber sits beneath the windscreen and supplies fresh air to the cabin.
Why It Rusts
- Leaves accumulate
- Drain holes block
- Water becomes trapped
Symptoms
- Water leaks inside cabin
- Rust around firewall
- Damp carpets
Repairing severe plenum rust can be labour intensive.
Firewall Rust
Rust frequently develops where water becomes trapped between panels.
Common Areas
- Plenum joins
- Heater box openings
- Wiring pass-throughs
Why It Matters
Firewall rust can be difficult to access and repair properly.
Front Guard Rust
Front guards are among the first visible areas to show corrosion.
Common Locations
- Lower rear guard sections
- Wheel arch lips
- Guard mounting points
Causes
- Mud accumulation
- Moisture retention
- Damaged paint
Replacement guards are becoming increasingly difficult to source.
Best Rust Converter
Recommended Product: Ranex Rust Converter
Benefits
- Converts surface rust
- Easy application
- Suitable for restoration projects
Best For
- Early-stage corrosion
- Rust prevention work
- Maintenance
Front Floor Pan Rust
Floor pans are a major concern on early Commodores.
Causes
- Windscreen leaks
- Door seal failure
- Heater box leaks
Symptoms
- Soft flooring
- Damp carpet
- Visible corrosion underneath vehicle
Always inspect beneath the carpet during pre-purchase inspections.
Rear Floor Rust
Rear floor damage often originates from front leaks.
Common Causes
- Water migration under carpet
- Rear window leaks
- Door seal deterioration
Rust can remain hidden for years beneath underlay.
Boot Floor Rust
Boot floors are another notorious Commodore rust area.
Common Causes
- Rear window leaks
- Tail light seal failure
- Boot seal deterioration
Inspection Tips
Remove boot mats and inspect thoroughly.
Look for:
- Surface rust
- Water staining
- Previous repairs
Spare Wheel Well Rust
The spare wheel well frequently traps moisture.
Symptoms
- Standing water
- Surface rust
- Pin holes
This area often indicates whether the vehicle has experienced long-term water leaks.
Door Bottom Rust
Door rust is extremely common on VB-VH Commodores.
Why It Happens
- Blocked drain holes
- Moisture retention
- Failed rust protection
Inspection Areas
- Bottom seams
- Drain openings
- Internal door structure
Replacement doors are becoming increasingly valuable.
Best Rust Prevention Spray
Recommended Product: Lanox MX4
Benefits
- Moisture displacement
- Corrosion protection
- Excellent penetration
Best For
- Door cavities
- Chassis sections
- Hidden rust-prone areas
Sill Panel Rust
Sills are a structural component and should be inspected carefully.
Symptoms
- Bubbling paint
- Swelling seams
- Soft metal
Causes
- Water ingress
- Blocked drain holes
- Previous poor repairs
Structural rust in the sills can significantly affect vehicle value.
Jacking Point Rust
The factory jacking points frequently trap moisture.
Common Issues
- Crushing damage
- Corrosion
- Structural weakness
Many owners discover sill rust when lifting the vehicle.
Wheel Arch Rust
Rear wheel arches are among the most visible rust-prone areas.
Causes
- Stone chips
- Moisture retention
- Mud accumulation
Common Symptoms
- Bubbling paint
- Rust around arch lip
- Previous repairs
Proper repair often requires cutting out affected metal.
Hatch and Tailgate Rust
For wagon models, tailgate rust is a frequent problem.
Areas to Inspect
- Lower tailgate seam
- Window surrounds
- Internal frame sections
Water accumulation is the primary cause.
Chassis Rail Rust
While less common than body rust, chassis corrosion should never be ignored.
Inspection Areas
- Rear suspension mounts
- Front chassis rails
- Fuel tank mounting points
Structural rust can quickly become expensive.
Best Weld-Through Primer
Recommended Product: U-POL Weld Through Copper Primer
Benefits
- Protects repaired panels
- Improves corrosion resistance
- Suitable for restoration work
Best For
- Rust repairs
- Panel replacement
- Fabrication work
Hidden Rust Areas
Many VB-VH Commodores hide corrosion extremely well.
Common Hidden Areas
- Under sound deadening
- Behind kick panels
- Beneath battery trays
- Inside quarter panels
- Under fuel filler areas
Always inspect thoroughly before purchasing.
Battery Tray Rust
Battery acid and moisture often damage the battery tray area.
Symptoms
- Surface corrosion
- Rust holes
- Paint damage
This area should always be checked during inspections.
Best Inspection Tool
Recommended Product: LED Inspection Camera (Borescope)
Benefits
- Access hidden cavities
- Detect concealed rust
- Easy to use
Best For
- Pre-purchase inspections
- Restoration projects
- Hidden rust detection
Common Rust Repair Mistakes
Repairing Over Rust
Rust should always be removed completely.
Ignoring Water Leaks
The source of moisture must be fixed first.
Using Body Filler as a Repair
Filler hides rust but does not stop it.
Skipping Internal Rust Protection
Many repairs fail because hidden cavities are left untreated.
Recommended Rust Prevention Package
For VB, VC and VH Commodores, a comprehensive rust prevention package should include:
- Ranex Rust Converter
- Lanox MX4 cavity protection
- U-POL Weld Through Primer
- Regular drain cleaning
- Window seal inspections
- Annual rust checks
These products help protect both restored and original vehicles.
Are VB-VH Commodores Worth Repairing?
The answer increasingly depends on rarity and overall condition.
Models such as:
- VH SS Commodore
- VC HDT Commodore
- VH SL/E
- Factory V8 examples
are becoming valuable enough to justify significant restoration work.
However, severe structural rust can quickly exceed the value of a project car.
Rust remains the biggest threat to surviving VB, VC and VH Commodores. While the engines, transmissions and suspension systems are generally straightforward to repair, rust can consume enormous amounts of time and money if left unchecked.
The good news is that most rust-prone areas are now well understood by enthusiasts and restorers. With careful inspection, early intervention and proper rust prevention, these classic Commodores can continue to survive for future generations.
Whether you’re buying your first VH Commodore or restoring a rare VC V8, understanding where rust forms and how to stop it is one of the most valuable pieces of knowledge an owner can have.
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