So yesterday I decided to have a transmission flush done. They use this cool tool that looks like a giant shock without the shaft, but has a cylinder that separates the old fluid from the new. Hose comes out of the top and bottom. They then pull the Trans lines on the radiator and they hook them up to the cylinder. You start your truck and the pump in the Trans pulls the new fluid in and pushes the old fluid into the cylinder. It's all controlled by your Trans, no electronics, and it ran 14 liters through. Here's a pic.. New on top, old on bottom.
The old fluid literally looked like mud!!!

anyways, no more surging, failing to shift, random downshifts, taking forever to shift, anything. It literally hasn't shifted so good since the day I bought it 80k ago! It used to take a long time to shift onto second and it was retarded soft about it. Now it hits gears firm and immediately. It also felt like it was dragging when getting on it before, now it just goes. If the Trans doesn't fail in the next month I'm going to pull the pan and put a new filter in it too. Might look into a shift kit of some sort as well. Anything to help it spin these heavy ass tires.
Sent from the drivers seat of my 05 4runner.