Every so often you notice it: The transmission shifts a little late, or maybe it seems to miss a gear entirely. Then it’s okay again… for a little while. Worst of all, there’s no rhyme or reason behind the condition. One minute it’s fine, the next it’s not. So you pop the hood to check the transmission fluid level. Then you notice it: A big mountain of corrosion on the battery terminals. You’ll have to take care of that, but it can’t have anything to do with the transmission, right?
Prevention is better than cure. You've probably heard that said plenty of times. The phrase is most often used to talk about health and medicine, but it is just as valid to apply it to vehicles. It's great if your problem can be sorted without much trouble, but even better not to have a problem in the first place. This is especially true when it comes to your vehicle's transmission, as this can be one of the more specialized parts to repair.
Your transmission suddenly isn’t shifting right. So what’s wrong with it? Do you need your transmission rebuilt? Good question. Unfortunately, the answer is: No one knows. At least, not yet. To find out what’s causing your transmission problem, a technician is going to have to perform a series of tests. Basically, these tests are designed to answer the simple question: “Is it inside or outside?” That is, is the problem inside the transmission, or in one of the many control systems that operates the transmission?