Mitsubishi Triton and Pajero Diesels: Don’t Skip the Timing Belt

Mitsubishi Triton and Pajero diesels need their timing belts replaced on time. Never late. This Triton is a good example of why: its balance shaft belt had failed, and it was very lucky the broken belt didn’t take out the main timing belt as well. If it had, the result would have been internal engine damage. If your Triton is due, or overdue, a Triton timing belt replacement is cheap insurance.

Timing belt vs balance shaft belt

The 4D56 diesel, found in many Tritons and some older Pajeros, uses two rubber belts at the front of the engine:

• The timing belt keeps the crankshaft, camshaft and fuel pump in perfect sync, so the valves open and close at exactly the right moment
• The balance shaft belt drives a balance shaft, which helps cancel out vibration and makes the engine run more smoothly

The balance shaft belt is smaller and sits close to the timing belt. These balance shaft belts are prone to failure, as this one was. When one breaks, pieces of belt can get caught up in the timing belt, causing it to jump teeth or snap.

What happens if the timing belt breaks?

When a timing belt fails on an engine like this, the pistons and valves can collide. That can mean bent valves, damaged pistons and a cylinder head that needs major work, which is far more expensive than replacing the belts on time. It usually happens without warning, often at speed, leaving you stranded.

When should you replace a Triton timing belt?

Follow the interval in your logbook or owner’s manual, which is set by kilometres and by time. Rubber belts age even when the vehicle isn’t driven much, so a low-kilometre Triton can still be due because of its age.

If you’ve bought a used Triton or Pajero and there’s no record of the belts being done, treat them as due. It’s also worth replacing the balance shaft belt, tensioners and idler pulleys at the same time as the timing belt. They wear together, and most of the labour is shared.

Warning signs to watch for

Timing and balance shaft belts often fail without much warning, so the interval is your best guide. That said, get your vehicle checked if you notice:

• Unusual ticking, slapping or squealing noises from the front of the engine
• A sudden increase in vibration
• The engine misfiring, running roughly or struggling to start

Triton timing belt replacement on the Gold Coast

We’ve written more about timing belt replacement in an earlier post. If your Triton or Pajero is due, include it in your next logbook service or contact us for a quote. Call 0478 499 369.