It doesn't matter whether its small claims court, municipal court, district court, etc.: the statute of limitations is based on the type of action. A warranty action is most likely a contract cause of action--you'd be suing for breach of contract. In that case, the statute of limitations on a written contract in Nebraska  is 5 years. That's 5 years from when the cause of action accrued; that is, it would be five years from when the dealer or manufacturer, etc., refused to honor the warranty--not five years from when you threatened them with a lawsuit. Assuming that the failure to honor the warranty occured less than 5 years ago, you should still have time, though don't delay any further--if you're going to file a lawsuit, file it. Good luck.