Not sure the last time transmission fluid was changed

I've only had my 2007 tundra since last March and according to Toyota's records they are not sure the last time the transmission fluid was changed. I'm hearing varying opinions on this one. It's got 172,000 miles on it, and if it's never been done before do I go ahead and do it or do I leave it alone?

 

I would do the drain and fill procedure once and see how the fluid looks and how the truck responds to a little fresh fluid.

The whole "don't change your transmission fluid if it hasn't been done before" tends to apply more to trucks from the big 3 rather than Aisin products.

 

I did 3 drain and fills on mine at 175K. Mine was light brown and didn’t have that burnt fluid smell. I cracked the plug a few hundred miles after the 3rd drain and fill and let a few drops land on a white paper towel and the fluid didn’t look perfect, but it didn’t have any brown in it. I plan on doing it one more time at the next oil change.

 

My new-to-me 2007 with 201,000 miles had one record showing a transmission service at 30k. I did three drain and fills over three weeks, did the proper fluid level check procedure, and now at 205,000 miles no issues.