Parts for your 1991 Mitsubishi Pajero-Drive belt tensioner

1991 Mitsubishi Pajero drive-belt tensioner — is it actually a thing on this model?

Short answer: no, a conventional automatic drive-belt tensioner isn’t used on the 1991 Mitsubishi Pajero. Technical references including the Mitsubishi Pajero/Montero Factory Service Manual (1989–1991 editions, sections covering “Fan and Alternator Belt,” “Power Steering Belt” and “A/C Belt”) and well-known aftermarket manuals such as Gregory’s Service and Repair Manual for Mitsubishi Pajero 1983–1991 and the Haynes Mitsubishi Montero/Pajero 1983–1993 manual show the model running multiple individual V-belts with manual adjustment points. Those manuals detail adjustment via the alternator and power-steering brackets, plus a jackscrew-adjusted idler for the A/C belt. There’s no spring-loaded serpentine-style accessory tensioner specified. Don’t confuse the engine’s timing-belt tensioner (on 6G72 V6 and 4D56 diesel timing systems) with an accessory drive-belt tensioner — they’re separate systems and parts.

Why isn’t a drive-belt tensioner used here? The 1991 Pajero sits in the era before a single serpentine belt became the default on many vehicles. Mitsubishi designed these engines with multiple V-belts, each one adjusted at its own component or an adjustable idler. It’s a simple, robust setup that suits remote-area service: fewer specialised parts, straightforward roadside adjustment, and low cost.

• Alternator/water pump belt: tensioned by moving the alternator along its pivot/adjuster.
• Power steering belt: adjusted at the pump bracket.
• A/C belt: uses an idler pulley with a jackscrew to set belt tension.

What owners should do instead of “changing the tensioner”: check and set belt tension during regular servicing. If there’s a chirp or squeal on cold start, dimming lights at idle, heavy steering, or the A/C clutch slips, that’s a nudge to inspect belt condition and adjustment. Replace any belt that’s glazed, cracked, fraying, or leaves rubber dust. When setting tension, follow the deflection specifications in the relevant workshop manual and re-check after a short run-in, as new belts can settle. Also eyeball pulley alignment and the A/C idler bearing — if it feels rough or noisy, replace the idler pulley. Going too tight is just as bad as too loose, over-tension can chew out bearings on the alternator, water pump, and power-steer pump.

Referenced technical sources: Mitsubishi Pajero/Montero Factory Service Manual (late 1980s–1991, Engine sections for accessory belts), Gregory’s Service and Repair Manual – Mitsubishi Pajero 1983–1991, Haynes Repair Manual – Mitsubishi Montero/Pajero 1983–1993. Each details manual belt adjustment and shows no automatic accessory drive-belt tensioner used on the 1991 Pajero.

Popular questions

Does a 1991 Pajero have a serpentine belt with an automatic tensioner?
No. It uses multiple V-belts with manual adjustment at the alternator, power-steer pump, and an adjustable A/C idler. There isn’t a spring-loaded serpentine-style tensioner on the accessory drive.

What part is often mistaken for a drive-belt tensioner on this model?
Two common mix-ups: the A/C idler pulley (which is adjustable but not automatic), and the timing-belt tensioner inside the timing cover. The timing-belt tensioner doesn’t set accessory belt tension.

How do you stop belt squeal on a 1991 Pajero if there’s no tensioner to swap?
Inspect belt condition, clean pulley grooves, check alignment, and adjust tension at the correct bracket or A/C idler. Replace worn belts and any noisy idler pulley. Set tension to the spec in the workshop manual and re-check after a short drive.