I have a 2009 Volvo S80 (Aisin transmission) with 138000 miles and a 2002 Toyota Sienna with 212000 miles. I'm fairly certain the transmission fluid has never been changed on either one. On the Sienna (it actually has a dipstick) the fluid is very dark. Neither one is having any shifting problems. Should I even bother changing the fluid on either one or let them go?
As Scotty in his YouTube videos have said, if you've skipped the ATF changes throughout the years and attempt to change/flush it now, you may be SOL and living on borrowed time.
The ATF will likely be filled with debris that provides the pressure to help drive/run the vehicle.
If you still go ahead with changing the ATF, you may end up in a scenario wherein the transmission starts slipping or completely fails.
The recommendation is to change every 50,000 miles or every 5 years, whatever comes first.
My primary vehicle was a Subaru, 08. We changed ours at about 60,000 miles at year...6-7. Little late. Thankfully nothing bad happened.
Second vehicle I purchased used. Had about 80,000 km on the Toyota Avalon. Was changing fine, tight. But the ATF was dark like yours. Started slipping a bit. Not terrible, but it had to rev up more to get the same power output. Wasn't the same. Scotty was right.
Long story short. You neglected on maintenance. Stay on top of it next time. Keep an eye on coolant + engine oil changes.
Start looking for a new car/budgeting for a new car.
