Go ahead and change the serpentine belt, tensioner and idler roller when replacing an alternator on your car or truck.
By the DIY experts of The Family Handyman Magazine:June 2010
Examine idler rollers for wear patterns. If you see wear, they're not spinning freely.
You bring your car in for a new alternator and the mechanic wants to change out the serpentine belt, the tensioner and the idle roller too. Is it worth it?
Yes. Your mechanic is actually looking after your best interests. Belts, tensioners and idler rollers rarely last the life of the vehicle. The additional labor for the idler roller is minimal (about $10), and the labor for the tensioner usually runs about $50. If you plan to keep the vehicle, you'll save money in the long run by replacing these parts now.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.
