Old Hilux interior plastic cracks because decades of sunlight and heat slowly break down the plastic itself, until it turns brittle and gives way at stress points like screw tabs and openings. Replacing a cracked piece with a reproduction in a heat resistant material is the practical fix. Here is what is going on, what to look for, and your options.
Why does old plastic trim crack?
Plastic is made of long molecular chains. When sunlight (UV) and oxygen attack those chains, they break into shorter pieces. Materials testing labs describe this as photo-oxidative degradation, and list the visible results as yellowing or discolouration, loss of strength, embrittlement and cracking.
Heat makes it worse. A NIST study on accelerated weathering of a common plastic (HDPE, not the plastic used in a Hilux) found that it lost its ability to stretch faster when UV intensity and temperature were higher. The damage also starts at the surface, which is why an old part can look fine from the front and still snap when you handle it.
A Hilux dash sits right behind a big sloping windscreen, in the Australian sun, for years at a time. That is about as hard a life as interior plastic gets.
What cracking looks like on an early Hilux
From the parts we have handled and described on our product pages, original early Hilux trim tends to show the same problems:
- Cracks around openings, such as the radio opening on the centre dash face
- Missing or snapped mounting tabs
- Warping, where the part no longer sits flat
- Sun-fading, where the surface goes chalky or grey
- Brittle edges that chip when you try to remove the part
If your part is already brittle, go slowly when removing it. Support the area around each clip or screw, because a part that has survived 40 years can break in a second if it is forced.
Can you repair a cracked dash part?
A small crack can sometimes be glued or filled, but it rarely lasts. The surrounding plastic is just as aged as the crack, so the repair tends to fail next to the original line. Repairs also struggle where the part carries load, such as around a radio opening or a switch.
A repair can make sense if the part is rare and the damage is cosmetic. If the part is structural, missing tabs, or warped, replacing it is usually less frustrating than patching it again and again.
How do you tell if a part is too far gone?
Press gently on the area around each screw hole and opening. If you can see fine cracks spreading from the corners, if the edges flake or chip, or if the part has bowed so it no longer sits flat against the dash, it is past saving. Sun-faded colour alone is cosmetic and can often be improved with cleaning.
Take photos of the part before you remove it, and again from the back. They help when you check fitment against a replacement, and they help us if you ask about a custom part.
What are the replacement options?
You can hunt for a good second-hand original, or fit a new reproduction. Good originals are getting harder to find, and a clean one is often just as old and just as brittle as the one you are replacing.
We make reproductions of several early Hilux interior parts. They are aftermarket parts, not genuine Toyota parts, and are not made or endorsed by Toyota. The OEM numbers below are for reference only.
| Part | OEM reference | Years | Material |
|---|---|---|---|
| Centre dash face | 55434-89133 | 1982-1983 | ABS-GF |
| Right hand dash face | 55432-89105 | 1979-1983 (RN30, RN40, LN30, LN40) | ABS-GF |
| Internal vents (pair) | None listed | 1979-1983 (RN36, RN46, LN36, LN46 and related) | ABS-GF |
Always confirm fitment before purchasing, and compare the photos with your original part.
Why do we print in ABS-GF?
ABS-GF is ABS reinforced with glass fibre. On our product pages we describe it as stiffer and more heat resistant than plain ABS, so it holds its shape in a hot cab. It has a textured matte black finish straight off the printer, and it can be sanded and painted if you want to colour-match your interior.
We cover how ABS compares with other options in our ASA vs ABS vs ABS-GF guide. No plastic is permanent in direct sun, so a sun shade or windscreen cover still helps any dash, original or new.
How to look after interior plastic once it is fixed
- Use a sun shade when parked outside
- Park in shade or a garage when you can
- Clean with a mild cleaner, not harsh solvents
- Check clips and screws are tight but not over-tightened
For the full list of what we make for the dash, see our dash parts guide.
Questions we get asked
Why did my Hilux dash crack when the rest of the car is fine?
The dash gets the most direct sun and heat in the whole cabin. Plastic parts that sit under the windscreen age faster than parts lower down in the shade.
Can I paint a reproduction part?
Yes. Our ABS-GF parts can be sanded and painted if you want to match your interior. Our own product pages list the standard finish as textured matte black.
Will a reproduction fit my truck?
Each listing states the exact years and models. Please confirm fitment before purchasing, and message us if you are unsure.
What if you do not make the part I need?
Send us a request on our custom parts page. If you have a rare part nobody makes any more, Project Save the Cars may also be an option.
If your centre dash face is cracked around the radio opening, start with our centre dash face, or browse the Toyota Hilux parts collection. Orders are posted from Bundaberg, QLD.