While I will admit upfront that I'm an idiot and at 104K miles I have only just now understood that even the ATF needs a change unlike what Toyota says.
So doing a drain and fill last weekend it came out nasty black and my retired mechanic friend who helped me drain and fill told me he wouldn't expect my transmission to last very much longer after draining only two quarts from the pan and being able to replace three with no issue.
I was getting the rumble strip feeling since last year and after using some lucas transmission conditioner it seems to have ended. But Im rather embarrassed to my lack of attention paid to the transmission but Im curious...

How long could a not very well maintained transmission last even after finally beginning to do fluid changes for it? It shifts a little nicer now but still a little slow on the down shift to gain speed but it still does what its designed to do. Idk if I have a few more years or a few thousand more miles though and thats what got me concerned. He says it'll be ok for now but that I should shop around for another one to put in it thats in better shape.

 

Being that its a sealed transmission, I hope you followed the proper procedure for the "Drain and Fill". Some of these transmissions you have to replace exactly what you took out. And there is a 3 separate bolts for drain/fill. Having said that, Toyota/lexus are the only transmissions I have seen firsthand have nearly black transmission fluid replaced with new and drive off okay. I can't say the same for HONDA or very many domestic brand cars.

 

Can anyone direct me to a turorial in replacing tundra auto trans fluid? My friend wants to replace his 2005 tundra fluid.
Thx!!