Transmission oil change/flush

Hey all!

So I’m having trouble deciding if my V8 needs a flush or just a drain and fill on the transmission oil. I bought the car with 207K on it and I am unsure if the transmission oil was ever even changed. I plan on towing in a couple months so I want to make sure the car is in good shape. Plus I’d feel better knowing there’s fresh oil in there. I called a local shop and they said they’d only do a drain and fill. Is this sufficient? I’d have liked to tackle this myself but sounds a bit too sensitive to mess up. **Side note.** At times it does feel a bit rough going into D gear.

 

Very good references Ive used a few times for info. If you just want to drain and fill, here: https://thetrackahead.com/projects/...-fluid-flush-and-fill-4th-gen-toyota-4runner/ If you want to drain, flush, fill, here:

 

This car is not new, so you should prevent all the risks that may happen.

 

I hear you, I've struggled w the same call. Last fall I bought a 2007 V8 Limited with 145,000 miles. According to the Toyota app it looks like it was serviced pretty regularly, visits to the dealer every 5k-10k miles for "service." And the it's not using or leaking any oil. But there's nothing that actually says explicitly that the transmission was ever drained/filled. I've drained/filled the diffs and TC. Done the same with coolant. I want to get the transmission done, but I'm afraid I could disturb something and cause problems when there aren't any now.

 

I would just drain and fill.

 

It's a gamble any way you go.

Not doing anything presents the highest risk for trans issues/failure.

Many will warn against a full cooler line flush because, as the theory goes, if the friction discs are worn bad the friction material still present in the fluid may actually be helping keep the trans from slipping and replacing all of the fluid may cause it to start earlier than it was inevitably going to anyway before long. Some makes of transmissions have had many reports of this happening (cough-GM-cough). Not a widely known issue with Toyotas.

Just a drain and fill might seem like the safest bet BUT only if you know what type fluid is in your tranny. Do you know if the previous owner did any sort of transmission fluid service? If so, did they use Toyota's specified WS ATF fluid required for 2004 and newer 4Runners (2003 still used Type IV ATF) or did they change to what is marketed as an equivalent like Valvoline MaxLife? I'm not trying to argue against the use of a third party trans fluid BUT I will point out that they are not compatible with each other. If you're going to go with anything but Toyota WS in a transmission that still has the factory fluid in it then a full flush is in order to make that change. Adding a couple quarts of one type fluid to another is a bad idea. if you don't already KNOW what's in yours then .... ?