It wasn't too many years ago that broken timing belts were a fairly common occurrence that would naturally lead to belt replacement. But with improvements in belt materials and technology, as well as better informed consumers, timing belt replacements at our shop are now almost exclusively performed as preventive maintenance. This is good news for both the shop and your customer. For the shop, it prevents a surprise job being towed in when your schedule can least absorb it. And there's never a good time for the customer to experience an on-the-road breakdown, not to mention the potential catastrophic damage that can result from a failed belt.

But like any other maintenance operation, it's our job to keep the customer informed of when the timing belt should be replaced and why it should be replaced. This month, we'll be looking at the Mazda line of vehicles, but most manufacturers use similar recommendations. As a general rule, we recommend replacement at 90,000 to 100,000 miles.

At the same time, we always recommend a water pump replacement and a set of drive belts to ensure a job that will deliver another 100,000 miles without having to go under the covers again. While we'll be looking at the nuts and bolts of a 2002 626 for this article, other Mazda models are similar. And, as always, don't dive into anything without reviewing service information procedures.

BELT REPLA...