Slippery belt is common to van -- but there's a fix

Dear Tom and Ray:

I have a 1998 Chrysler Town and Country Minivan with the six-cylinder engine. Whenever I drive through a puddle, the belt slips off. All of the original undercarriage guards are still present and in factory condition. I have replaced the water pump, idler pulley and tensioner, to no avail. This occurs so often that I must carry a specially modified wrench underneath my driver's seat so I can stop and put the belt back on. I have become so proficient at this that I can put the belt back on in less than four minutes. The slightest amount of water will cause the belt to slip off. During the winter melt and spring rain, I must navigate the roads as if I am driving through a field of land mines and avoid all pools of water, regardless of size. I have asked numerous mechanics, both shadetree and dealership, but have stumped them all. Can you explain the cause and provide a solution so that I may hang the wrench back up in my garage?
-- William

Ray: Well, we can't fix your car, William, but if you really can change a belt in four minutes flat, I'd be happy to offer you my brother's job.

Tom: Actually, this is a common problem with Chrysler minivans of that era. Usually when a belt slips off, it's due to either a worn-out belt or a misaligned pulley.

Ray: If the pulleys aren't all in the same exact plane, the one that's out of line will try to tug the belt either forward or backward out of that plane, and with the help of something slippery -- like some water -- it often can succeed in pulling off the belt.

Tom: And in fact, Chrysler issued a Technical Service Bulletin for this problem. For $300, Chrysler will replace the mounting bracket of the idler pulley to better align it with the other pulleys.

Ray: Unfortunately, we've been told that often this doesn't solve the problem.

Tom: So about five years ago, Gates came up with a set of replacement parts you can have installed that WILL solve the problem.

Ray: The Gates kit contains a special double-sided, grooved belt and matching grooved tensioner and idler pulleys. So the belt matches the pulleys, and sort of locks into place. That makes it much harder for the belt to come off.

Tom: The kit costs just over $100, and your mechanic can get it from his Gates supplier and install it for you (we're told Goodyear has a similar kit). Then you can hang that wrench back up until the next thing breaks. Good luck, William.

(Car Talk is a nationally syndicated column by automotive experts (and brothers) Tom and Ray Magliozzi. Write to them at the Car Talk website.)