Parts for your 1998 Daihatsu Terios-Drive belt tensioner

1998 Daihatsu Terios drive-belt tensioner — is it used?

Conclusion: a separate, automatic drive-belt tensioner is not used on the 1998 Daihatsu Terios (J100 series, typically with the 1.3 HC‑EJ engine). Technical references show the accessory drive uses manually adjusted belts rather than a spring‑loaded serpentine tensioner. The Daihatsu Terios J100 Series Workshop Manual (1997–2005), Engine Mechanical/V‑ribbed belt section, specifies setting alternator belt tension by moving the generator on its slotted bracket and locking it, and setting the A/C belt via an idler pulley with an adjusting bolt. The Daihatsu/Toyota Electronic Parts Catalogue for J100G lists an “Adjusting Bar, Generator” and a “Pulley, Idler (for compressor)” but no “Tensioner Assy, V‑belt”. Major belt catalogues for AU/NZ applications (e.g., Gates and Dayco) likewise list two separate accessory belts and no automatic tensioner for this model year.

Why it isn’t used: the Terios of this era runs separate accessory belts rather than a single serpentine with an auto tensioner. The alternator/water pump belt is tensioned by shifting the alternator, and the A/C (and power steering where fitted) belt is tensioned with a simple idler and adjuster screw. It’s a straightforward, cost‑effective layout that suits the compact engine bay and keeps parts count down—handy for owners in Australia and New Zealand where easy roadside or shed servicing is a bonus.

What owners should do instead: because there’s no automatic tensioner to maintain or replace, routine servicing focuses on belt condition and manual adjustment. At regular services under the bonnet, check for cracking, glazing, frayed edges, and any squeal on start‑up. Adjust belt tension using the alternator pivot and lock bolts for the main belt, and the idler’s adjuster for the A/C belt. After fitting new belts, re‑check tension after a few hundred kilometres as they bed in. If there’s persistent noise, look at pulley alignment and the A/C idler pulley bearing rather than searching for a non‑existent drive‑belt tensioner. Note that the engine’s timing belt does have its own dedicated tensioner, but that’s part of the cam belt system and unrelated to the accessory drive.

• No automatic accessory drive-belt tensioner fitted
• Alternator belt tensioned by moving the alternator on a slotted bracket
• A/C belt tensioned via an idler pulley with an adjuster bolt
• Service by inspecting belts, adjusting tension, and checking idler bearing

Technical sources referenced: Daihatsu Terios J100 Series Workshop Manual (1997–2005), Engine Mechanical – V‑ribbed belt Inspection/Adjustment, Daihatsu/Toyota Electronic Parts Catalogue, J100G HC‑EJ – Crankshaft pulley & V‑belt/Generator sections, AU/NZ application catalogues from major belt manufacturers indicating no automatic tensioner for 1998 Terios.

FAQs

Does the 1998 Daihatsu Terios have a drive-belt tensioner?
No. It uses manually adjusted accessory belts—alternator tension is set by moving the alternator, and the A/C belt uses an idler with an adjuster. There is a timing belt tensioner, but that’s for the cam belt, not the accessory drive.

How is belt tension adjusted on a 1998 Terios?
Under the bonnet, loosen the alternator pivot and lock bolts, lever the alternator to set the belt tension, then retighten. For the A/C belt, use the idler pulley’s adjuster screw to increase or decrease tension, then lock it off. After any new belt is fitted, re‑check tension after a short running‑in period.

What if the belt squeals or there’s a chirp on start‑up?
That usually points to low tension, a glazed or worn belt, or a worn idler pulley bearing on the A/C side. Inspect belt condition, confirm alignment, set proper tension, and replace the idler pulley if its bearing feels rough. There’s no automatic tensioner to replace on this model.