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.

Related Articles

• How to Inspect a VB, VC or VH Commodore Before Buying
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• VB VC VH Commodore Suspension Problems
• Best Rust Prevention Products for Classic Holdens