Mitsubishi Challenger: 4D56 balance shaft belt shredding and taking the timing belt with it
4D56 balance shaft belt shredding and taking the timing belt with it is a common engine fault on the Mitsubishi Challenger on the 2009–2015 cars, and we rate it critical. Putting it right costs $900 to $6,500 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 12 documented faults on the Mitsubishi Challenger.
- Vehicle
- Mitsubishi Challenger
- Engine
- 4D56
- Years
- 2009–2015
- Fuel
- diesel
- System
- Engine
What you are looking at
No photograph available
What goes wrong
The 4D56 runs a second, inner toothed belt for the balance shafts, sitting behind the main timing belt. It is a consumable that has to be replaced at the same time as the timing belt, and it is routinely left in place to save an hour of labour. When it lets go it does not just stop the balance shafts: the shredded belt can wrap itself around the crankshaft pulley and jump or destroy the timing belt right next to it. The 4D56 is an interference engine, so a timing belt that jumps teeth or breaks lets the pistons hit the valves, and what should have been a belt service becomes a cylinder head rebuild. The two usual triggers are oil from a weeping front crankshaft seal soaking the belts, and incorrect tension at the last belt change - both Gates and Dayco publish Australian technical bulletins on getting the 4D56 procedure exactly right for precisely this reason.
What you would notice
- Last timing belt invoice with no balance shaft belt listed on it
- A rumble or vibration through the floor and pedals that was not there before, worst at idle and low revs
- Oil weeping or oily dust around the crankshaft pulley and the bottom of the timing cover
- Rattle, buzz or squeal from the front of the engine on start-up
- Timing belt interval passed on kilometres or years with no receipt to show for it
How to check it
Where to look. Behind the plastic timing cover at the front of the engine on the passenger side of the engine bay - the balance shaft belt is the inner belt, tucked behind the main timing belt. What you can actually see is the paperwork and any oil around the crankshaft pulley.
Ask for the invoice for the last timing belt change rather than just a stamp in the book, and read the parts list - you want to see the balance shaft belt, both tensioners, the idler and the crankshaft front oil seal on it, not just a timing belt.
Ask when it was done, at what kilometres, and by whom, then work out how far and how long it has run since.
Open the bonnet and shine your phone torch down the front of the engine behind the drive belts, looking for wet oil, oily dust or drips around the crankshaft pulley and the lower timing cover, because oil soaking into these belts kills them early.
Start the engine and listen at the front for a new rumble, buzz or squeal, and rest your hand on the gear lever at idle to feel for a vibration that another example of the same car does not have.
If the seller cannot produce a belt invoice, price a full belt job into your offer, because on an interference engine guessing is the expensive option.
What it costs to put right
$900 to $6,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.
Ask the seller
- “When was the timing belt last changed, and does the invoice list the balance shaft belt as well?”
- “Were the tensioners, idler and crankshaft front seal replaced at the same time?”
- “Who did the belt job - a Mitsubishi dealer, a diesel specialist, or a general workshop?”
- “Is there any oil leak from the front of the engine?”
Now check the Mitsubishi Challenger you are actually looking at
Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.
Where this comes from
- Gates Australia Technical Service Bulletin TSB_027_AU 'Following the OEM installation procedure correctly is critical on 4D56 DOHC engines'
- Dayco Australia technical bulletin TI00020, 4D56 belt installation
- newtriton.net thread 'Harmonic balancer shot'
- JustAnswer case report '2013 KB Triton 4D56 balance shaft belt failure - engine replaced'
Mitsubishi Challenger buyer questions
Is 4d56 balance shaft belt shredding and taking the timing belt with it serious on a Mitsubishi Challenger?
We rate it critical and common on the Mitsubishi Challenger. The 4D56 runs a second, inner toothed belt for the balance shafts, sitting behind the main timing belt. It is a consumable that has to be replaced at the same time as the timing belt, and it is routinely left in place to save an hour of labour. When it lets go it does not just stop the balance shafts: the shredded belt can wrap itself around the crankshaft pulley and jump or destroy the timing belt right next to it. The 4D56 is an interference engine, so a timing belt that jumps teeth or breaks lets the pistons hit the valves, and what should have been a belt service becomes a cylinder head rebuild. The two usual triggers are oil from a weeping front crankshaft seal soaking the belts, and incorrect tension at the last belt change - both Gates and Dayco publish Australian technical bulletins on getting the 4D56 procedure exactly right for precisely this reason.
How much does it cost to fix on a Mitsubishi Challenger?
$900 to $6,500 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.
Which Mitsubishi Challenger years are affected?
Our research records this fault on the 2009–2015 Mitsubishi Challenger. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.
How do I check for it before I buy?
Ask for the invoice for the last timing belt change rather than just a stamp in the book, and read the parts list - you want to see the balance shaft belt, both tensioners, the idler and the crankshaft front oil seal on it, not just a timing belt. Ask when it was done, at what kilometres, and by whom, then work out how far and how long it has run since. Open the bonnet and shine your phone torch down the front of the engine behind the drive belts, looking for wet oil, oily dust or drips around the crankshaft pulley and the lower timing cover, because oil soaking into these belts kills them early. Start the engine and listen at the front for a new rumble, buzz or squeal, and rest your hand on the gear lever at idle to feel for a vibration that another example of the same car does not have. If the seller cannot produce a belt invoice, price a full belt job into your offer, because on an interference engine guessing is the expensive option. Look here: Behind the plastic timing cover at the front of the engine on the passenger side of the engine bay - the balance shaft belt is the inner belt, tucked behind the main timing belt. What you can actually see is the paperwork and any oil around the crankshaft pulley.