Yeah a flush would work. If this is the first time it has been changed itll prolly fix it. Here is the how-to for the ATX from the FAQ section under transmission:
There's two ways. The first way is a drain and fill approach and the power flush. There is also a manual flush that I will also cover.
A)Drain and Fill - Jack the front of the car up a small amount. Remove the drain plug, using a 3/8" drive rachet. Allow the 4 quarts to drain out. After the ATF drains out, simply re install the drain plug and let the car down. Add 3.5 quarts and crank the engine. Hold the brake and work though all the gears. This ensures that all the fluid works through the system. Leave the engine running and check the fluid level and adjust as needed. You should only have to possibly add the last .5 quart.
B)Power Flush - This procedure calls for a mechanic to hook your ATX up to a machine that will force new fluid into the ATX case and, at the sametime, sucks out the old. The force of the fluid coming into the case cleans out most, if not all, contaminets throughout all parts of the ATX.
C)Manual Flush - To perform a tranny flush yourself, follow this little "How-To" by RoadRunner, Transmission Forum Moderator at CEG. Before you start put 4 quarts of WATER in a bucket and mark the INSIDE of the bucket with an INDELIBLE INK MARKER, at the top of the water level. When you get under the car, you will see two lines that go from the transmission to the passenger side of the car. One attaches to the BOTTOM of the radiator, while the other goes to the TOP of the radiator. Follow the line that attaches to the BOTTOM of the radiator back to the transmission. This is where you want to remove the line and then put the end of it into a bucket. Pour out the water and dry. Now you have a 4 quart measure inside the bucket ! Start the car and let it idle while the bucket fills. When it gets close to the 4 quart mark, turn off the car, and pour 4 quarts of ATX Oil into the Dipstick Tube. Take the 4 quarts in your bucket and pour it into the 4 empty ATX Oil bottles. You'll need to repeat this until the oil coming out of the line starts to resemble the oil you ar pouring into the dipstick tube.
This is more than likely the cause.
good luck!
