This is a 1997 Mazda 626LX 4 cylinder with only 25,470 miles on it. I only drive it around 1500 miles/year, and over the summer was taking a 5 mile trip up into the hills and back around 3 times a week. I'd put the car in 2nd gear when going down a long moderately steep hill to save my brakes. I've had a feeling in recent months (maybe for a year?) from time to time that maybe my transmission had a problem, but it was sporadic and usually it didn't happen. It would happen once in a while, maybe when getting started from a parking lot, just a kind of little jolt when the automatic transmission changed gears. I checked the transmission fluid a few weeks ago and it looked clean and full. Yesterday, I took the longest drive I've done in many months, around 30 miles one way, parked in a Costco lot and shopped for an hour or more, put my stuff in the car and started to make it to their gas pumps to top up, but I wasn't sure I was going to make it. It's as if it wouldn't go into gear, only tried. The car moved, but it stuttered, stopped, I heard a mild clunking, it almost seemed like it had rolled up on a log! It's hard to describe. It's as if a big animal, say a 700 pound boar was shoving the car! It seemed to be coming from the back and I took a 50 pound bag of flour out of the trunk and put it on the passenger seat next to me, thinking that the extra weight back there was part of the problem, crazy I know. At the time I was worried that my suspension had broken, and I took out a flashlight (it was just after dark, around 5:30PM), and walked around the car looking underneath and at all the wheel wells. I didn't see anything that looked unusual. Now, I was ~25 miles from home and knew only one way home, on the freeway and I was hell of nervous what would happen, didn't know if I was going to be able to go 1/4 mile even. I gassed up and asked a guy at the pump if there were any places I could have check out my car nearby. He thought so, but I didn't see anything other than a place that does brakes and something else, and an oil change place. I made it to the freeway and drove home through moderately heavy traffic at times that slowed to ~4 mph on average over a ~2 mile stretch, but the entire time once I got out of the Costco lot things seemed normal. I was nervous that something would suddenly go completely wrong and I'd have some catastrophe on the freeway, so I drove no more than 60 mph, mostly 50 or less the whole way and as close to the right as practical. I don't want to use the car until I have it checked out. Should I take it to a transmission shop? A recommended mechanic and have a general car inspection? If the transmission is disintegrating I have to wonder if the car is worth saving at this point. Or it could be something else, for all I know. What do you think?