Parts for your 2004 Mitsubishi Pajero-Drive belt tensioner

2004 Mitsubishi Pajero drive belt tensioner — what it does and how to look after it

Yes, a drive belt tensioner is fitted to the 2004 Mitsubishi Pajero. According to the Mitsubishi Motors Pajero/Montero NM–NP Workshop Manual (Group 14 – Engine) and major parts catalogues from Gates and Dayco for the 2004 model year, both the 3.8L 6G75 petrol and the 3.2L 4M41 diesel use an automatic accessory drive belt tensioner. Diesel variants also run a separate A/C belt with its own adjuster, but the main accessory belt still relies on a spring‑loaded tensioner.

On this Pajero, the drive belt tensioner keeps the serpentine belt at the sweet spot for tension, so the alternator, power steering pump, water pump and A/C compressor all play nicely under load. It constantly takes up slack as the belt wears and stretches, and its internal damping smooths out belt flutter and pulley vibrations that cause squeaks and premature wear.

For regular servicing, it pays to give the tensioner a proper once‑over every service or 15,000 km. Quick tells of a tired unit include belt squeal on cold start, chirping as revs change, a fluttering tensioner arm, a wobbling or gritty pulley bearing, or a belt that looks glazed, cracked or is wearing on one edge. Electrical warnings, heavier steering, rising temps or weak A/C can also trace back to a slipping belt from a lazy tensioner.

When replacement time comes, treat the tensioner as a matched pair with the belt. If the belt’s done a hard life or clocked a big number, throw a fresh belt on with the new tensioner, and consider renewing any idler pulleys while you’re there. Use the correct square drive or hex to relieve tension