Keep the accessory belt tracking true and quiet with the Dayco drive belt tensioner assembly, MPN 89480 — a heavy-duty automatic unit that applies steady spring load to the serpentine belt so it keeps spinning the alternator, air conditioning, fan and other engine accessories. It's engineered for heavy-duty applications and drops in as a direct-fit replacement for the listed trucks, including the 2000-2003 Ford F-650 and F-750 [L6-7.2L], Freightliner Century Class [6-12.0L], Kenworth T800, Peterbilt 379 and many International, Sterling Truck and Western Star models — see the Buyer's Guide tab for the full list.
Belt squeal or chirp, belt slip, rapid belt wear, or noise from the pulley are signs the tensioner may need replacing. If a worn tensioner is the cause, this assembly provides the correct spring tension.
Interchange: 38506 · 49506 · 45835 · 910001A · 910559A · VKM910001 · 910001
This part cross-references / interchanges with the following part numbers:
What does this Dayco accessory drive belt tensioner assembly do?
It's an automatic tensioner that applies steady spring load to the serpentine belt, keeping proper tension so the belt drives the alternator, A/C, fan and other accessories without slipping.
Is this the same as a serpentine belt tensioner?
Yes. This part is a belt tensioner, also called a serpentine belt tensioner. The facts list its belt type as serpentine and it's an automatic, clockwise-rotation unit.
What are the pulley specs?
It has a single flat pulley measuring 74 mm in diameter and 39.25 mm wide, with clockwise rotation.
How do I know if my tensioner needs replacing?
Common signs include belt squeal or chirp, belt slip, rapid belt wear, or noise from the pulley. Diagnose the cause first, since these symptoms can have other sources.
Will this fit my vehicle?
It's a direct-fit replacement for many heavy-duty applications such as the 2000-2003 Ford F-650/F-750 [L6-7.2L] and various Freightliner, Kenworth, Peterbilt and International models. Check the Buyer's Guide tab to confirm.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
