One problem related to axle assembly has been reported for the 1999 Mazda 626. The most recently reported issues are listed below.
I own a 1999 Mazda 626 ES with an automatic trans axle. The vehicle has been serviced regularly, and has 78,000 miles on the odometer. Last week the transaxle failed as it dropped down a gear, to go up a slight hill, at approximately 70 mph on the interstate. As a result, the transaxle will not shift out of second gear. The resulting rebuild of the transaxle will cost $2100, half the current trade-in value of the vehicle. My concerns are two-fold. First, the transaxle should not have failed at 78,000 miles; this is not a normal situation for a well-maintained vehicle of this age and mileage. Second, after a search through internet discussion sites, and discussing the issue with a CO-worker who had the same thing happen with a 1995 Mazda 626, it has become evident to me that Mazda 626 transaxle failures are a fairly common, seemingly systemic problem.