Well, with a zero-clearance engine, I've always used the dealer to change the belt and water-pump, and extracted a 60,000 mile warranty on the belt and pump from them in writing on a copy of the ticket before they do the work. It's too critical if it scroos up. On my car, the belt breaks or jumps time, it's the engine. Besides, for all my bytching about the Stealerships, for critical engine work, I'd rather have the mechanic do it that's done a thousand of them than a mechanic that's never done one. They also let you know if the pulleys are cracked, the tensioner is good, all that. Based on those conditions they've always agreed to the coverage on the belt, pumps and tensioners.