Serpentine Belt Replacement

With all the increasing complexity under the hoods of today's vehicles, it's heartening to see a component that actually decreases it: the serpentine accessory belt, along with its self-adjusting tensioner.


Before the mid-to-late '80s, most vehicles had a multiple-V-belt accessory-drive configuration, sometimes with as many as five individual belts, which often had to be manually adjusted, separately and in sequence. This system was not only time consuming to manufacture, assemble and service, but also required more room under the hood to accommodate the "staggered formation" required for the accessory mounting locations.


The serpentine (single) belt, also known as the "S-belt," eliminated most if not all of those drawbacks. It's cheaper to produce and easier to service, and also provides packaging advantages at the front of the engine. This system still needs servicing, however. We'll cover when and how to change the belt and its tensioner, as well as other points of inspection associated with this procedure.

Time Change?
When to change the belt depends on a few things but, generally speaking, for optimal performance the S-belt will have to be changed more often than its "V" predecessors. In terms of time and mileage, this would translate to between 30,000 and 60,000 miles, or four years. Under-hood heat, accessory load, the quantity of accessories, and exposure to road debris all affect the longevity of the belt. If the manufacturer specifies a replacement interval, go with that recommendation unless the belt fails inspection at any maintenance interval before then.


When inspecting the belt, if it appears to be glazed (shiny), show cuts, cracks or other deterioration on either side or on the edges, has chunks missing from it, or is merely noisy—it has to be changed. It's helpful if you can determine the cause of a particular problem—from normal wear to damage—so you can be assured that the replacement belt will last the full duration of its service life. We'll touch on related component inspection (necessary especially if the belt failed prematurely) after covering removal of the belt.