I have just noticed that my tranny is "acting up" ....when driving under normal conditions and reaching about 65MPH it shifts and then down shifts immediately....giving a sudden jerk..I have 142,000 miles on it and to my knowledge fluid has never been changed...I have put 80,000 on it myself. Fluid level is full ....maybe alittle on the brown side in color...And I also have noticed my shifter indicator has become a little offset..doesn't go completely into "D" it is kinda in between "N" and "D". I noticed all of this after driving it to a location...parking...and this all took place on my departure.Everything seemed fine on the initial trip.So my question is....change the fluid or look further into tranny repairs?