Two Navaras in the same week came in with the clutch pedal box cracking apart and the firewall cracking with it. That looked like a common failure, but we could not find a clear repair procedure online — so on the first job we 3D-modelled a reinforcement plate, fabricated it, and published the drawing so the next one is faster to find and make.
The failure
Cracked clutch pedal box on the D40. The fuel filter in front of the clutch master cylinder has to come out, and the lines capped, to get access.
After removing the master cylinder and linkages we checked the bushes — OK on the first box; worn on the second (new bushes fitted). The two pedal boxes were slightly different: the older Navara box was stronger; the newer ~2010 box was lighter with less steel and cracked with less of a heavy clutch feel.
Pedal box welded up and ground back flush to the firewall face (before paint).
Firewall plate
Firewall cracks were bad. The plate covers them. Welding and grinding the cracks themselves is possible but hard to access for a clean finish, so the plate was fitted and welded around the outside. With the pedal box, plate and master cylinder installed, the firewall is sandwiched and much more rigid — no flex.
- Plate made ready to install
- Plate in position before welding
- Welded and painted reinforcement plate
Plate drawing — PDF download
Printable drawings for the reinforcement plate:
If you still have the original CAD / 3D model file, drop it in
_import\snapshots and we will add a model download beside the PDFs.
Prevention
Replace the clutch when it starts to feel heavy — that is what drives this cracking of the firewall and pedal box.
Book in
D40 with a heavy clutch, cracked pedal box or flexing firewall? Call the workshop — we know this repair.