I have an Automatic, with Overdrive.
I bought the car about one month ago, and don't know any history beyond that. I changed all fluids and filters, like I do everytime I buy a used car, including the tranny fluid and filter. It looked normal for a car with 100K miles on it. (No, I didn't flush it, just a change).
Ever since I bought the car, the transmission has always had a "bump" as you aproach a Stop -- it jerks the car in the last second before stopping. I don't know what the cause is, so I decided to "live with it".
Now, and quite suddenly, it started shifting very erratically.
Sometimes, while accelerating, the transmission will slip, allowing the motor to rev quite high before re-engaging again. Other times when accelerating, it doesn't want to go into third. While coasting on the flat, it'll hunt from OD to 3rd to OD to 3rd (etc), which it never did before. But the scariest thing is that while you're coasting (down a hill), the transmission will suddenly (and violently) jerk into low gear and then back out. It feels like the brakes get jammed on and then released a split second later.
I tried to buy a Modulator Valve, but was told my tranny doesn't require one -- they told me "it's electronically controlled." The tranny pan says "AXOD", but can the tranny be an "AXOD-E"?
I thought maybe the speed sensor is at fault, but I think I have a Cable pickup instead (and the speedo seems to be working fine).
The "Check Engine" light does not come on (and I'm positive that the bulb is not burned out).
What is going on? ANY IDEAS AT ALL WOULD BE APPRECIATED!!