my 2000 runner (auto tranny) is having some shifting issues. There are 56,000 miles (89,000 km's) on it and i know the transmission fluid hasnt seen a change in over 12,500 miles (20,000km's) since i have owned it. its #1 on my list of things to do. Anyway, its always occasionally "clunked" into gear once the brake pedal is released from a stop. Now its having shifting problems where it wont shift smoothly or else it shifts late. Is this a fluid issue? also, the last day or 2 it has all of a sudden started idling around 1500-2000 rpm when its warm without any of the accesories on- any idea there? let me know what you think.

 

The only issue I have any advice on is the clunking....it happens to my 99' Tacoma as well....the Toyota mechanic told me it was a minor lubrication issue, nothing to be concerned over. I believe its the driveshaft, since it is a two piece it "clunks" into place when not lubricated well enough. I could be wrong, but thats what the guy told me. Check it out.
I never got around to getting mine lubricated, I just got used to the feeling.