Parts for your 1989 Mitsubishi Pajero-Drive belt pulley

1989 Mitsubishi Pajero Drive Belt Pulley — Purpose, Care, and When to Replace

Technical sources confirm that drive belt pulleys are absolutely used on the 1989 Mitsubishi Pajero. The Mitsubishi Motors Factory Service Manual for this model year (covering 4G54, 4D56/4D56T and 6G72 engines) details multiple accessory drive belts and related pulleys, including the crankshaft (harmonic balancer), alternator, power steering pump, A/C compressor and idler/tensioner pulleys. Gregory’s Workshop Manual for Pajero 1983–1996 and the Haynes Montero/Raider 1983–1991 manual describe the same layouts and service procedures, while the Mitsubishi ASA parts catalogue lists these pulleys by part number across 1989 variants.

For this Pajero, the drive belt pulley system is the workhorse that spins the alternator, water pump, power steering pump and A/C compressor. Most 1989 models use multiple V-belts rather than a single serpentine belt, so each accessory runs on its own pulley track. The crankshaft pulley (harmonic balancer) drives the lot, while idler or adjustable accessory mounts set belt tension. If a pulley’s bearing gets noisy or the harmonic balancer’s rubber layer starts to separate, it can throw belts, squeal, or worse—overheat the engine if the water pump stops turning.

As part of sensible servicing, it pays to check belts and pulleys every 10,000–15,000 km. Look and listen for:

• Chirps, squeals or rumbling near the front of the engine
• Cracks, glazing or fraying on belts, black rubber dust around pulleys
• Wobble at the crank pulley or free play in idler/alternator pulleys

Replacement is straightforward with basic spanners and a belt tension gauge. Always disconnect the battery, note belt routing, and set correct tension (the manuals specify deflection ranges). If the harmonic balancer shows any wobble or rubber delamination, replace it promptly—on 6G72 V6s, that’s a known ageing issue. Idler pulley bearings on 4D56 diesels also deserve attention, especially on vehicles that have done a lot of towing or off-road work.

When fitting new belts or pulleys, clean the grooves, align the pulleys true, and recheck tension after the first few hundred kilometres as fresh belts bed in. Genuine or quality aftermarket parts help keep the Pajero’s electrics charging, steering light and cooling spot-on—key for touring in Aussie and Kiwi conditions under the bonnet’s heat and dust.

How often should the drive belt pulleys be replaced on a 1989 Pajero?

There’s no fixed time limit for pulleys, but many last well beyond 150,000 km. Replace a pulley if it’s noisy, rough, misaligned, or if the harmonic balancer rubber shows cracks or separation. Belts typically get replaced every 60,000–100,000 km or when condition dictates.

What are the signs a Pajero harmonic balancer is failing?

Look for a wobbling crank pulley, visible cracking or shifting of the rubber layer, rhythmic vibration at idle, or recurring belt squeal despite correct tension. Any of these call for immediate inspection and likely replacement.

Can a worn idler or alternator pulley damage other components?

Yes. A rough or seized pulley can overheat and shred a belt, which can take out charging, power steering or cooling in one hit. It can also stress bearings on the accessory it drives, leading to bigger repair bills.