OK, so i've had my VX since this past Saturady. 2001 EB with 25,000 miles. Everything is kosher.

Today I drove to work (13 miles, non highway), no issues. Around noon I went out on lunch. I drove to the post office (3 miles away), no issues. When I left the post office, I noticed that the trans was making a hard shift out of first gear. At about 20mph, the truck made a disturbing "clunk", the rpms dropped quick and then everything seemed fine. I went another mile and stopped at a pizza joint for lunch. After lunch, I checked to see if I was leaking anything, negative. So I started her up and drove back to work, with no clunking anymore. I don't get it.

So, could this be a sign of something really bad? Or is this most likely a case of dirty trans fluid? I am going to get this looked at as soon as I can.

Any help from the expert on here would be much appreciated.

Bart