Join Date: Mar 2011
Location: Mid Hudson Valley, NY (USA)
Re: Dealership claims only they can do transmission flush
At 6 years and 100k miles, I'm going to weigh in (also as an old timer) that it's prudent to go forward with the recommended service. Lifetime fluids is a nice idea, but in reality individual use patterns vary so widely that it's tough to say whether degraded chemistry can begin to do harm. On my last Sienna, I did all three as the van approached 90k. It's not that terribly expensive to get it done, and the potential payback could be big.
At least when you do these services at Toyota, you are practically guaranteed that the right fluids will be used. Mixing coolant types can cause sludge buildup in the heater core. And I don't like mixing Toyota WS with Valvoline, etc.
Getting the fluid level right on the tranny can be tricky. There is an on-board thermocouple that is read out, and the tranny fluid must be at 114' (IIRC) when the overlow is capped. Guessing here isn't what you want to have happen.... If you get it done by an independent, make sure they REALLY know how it's done.
Current: '15 Sienna Limited Premium (FWD), '14 Subaru Outback, '13 Honda CRV AWD.
Past: '08 Sienna LE (FWD), '02 Subaru Outback, '02 Honda Odyssey EX