Being someone who has just had the AWD transmission fail (severity of failure unknown as still being diagnosed) at 80,000 miles, I would go with the universal time-frame of between 25-50k miles. My fluid at about 75k was just starting to change colour and I was just starting to think about having it done, and now my hand has been forced by the transmission dying without warning. I drive mostly city and would say 90% of the miles on my car are city in a climate similar to Hawaii.

My new schedule when the new box goes in will be 600 miles (drop pan and inspect; new fluid to top off), 3000 miles(same if there were no filings in the last drop) and the next change will be 10k miles if the filter wasn't changed at 600 miles it will be here.

At $10,000 dollars to replace new for old I am even thinking adding a aux trans cooler too, its cooled by the radiator now but I want some extra safe guards.

 

phoenix, your fluid condition almost certainly had nothing to do with your transmission failure. If they took it part, I bet they'd find a pure mechanical failure; likely a part defect that took a while to fail.

anne--if the fluid doesn't smell burnt and the transmission still behaves well, shifts smoothly, then leave the fluid alone. It's normal for the fluid to darken as it ages; little correlation between color and fluid performance. Fluid that is dark AND smells burnt is bad.

Always a good idea to check the fluid condition every 10 to 15k, if for no other reason, to make sure the level is OK.

Save the money for tires or brake pads, which you know are required periodically.

 

Takes apprx 30 minutes to open AT drain plug and drain apprx 3.5 quarts of AT out and refill with same amount as you drained. Super easy and you don't even need to jack the Highlander up to do it. I do a drain and fill every 3-4 oil change so every 15-20k miles depending on appearance and smell of the AT fluid check via dip stick. Over the course of 100k miles I will have swapped in apprx 18-21 quarts of fresh fluid into the AT. For me it is cheap insurance with minimal effort to keep the trans working smoothly and possibly minimise AT wear over time.

 

I believe in flushing every 50k. I do it with all the fluid systems. Toyota isn't going to step up and replace your transmission just because you followed their recommendations. On the newer Toyota's (for example) Toyota recommends 100k engine coolant interval but after the first 100k, they recommend every 50k and nobody at Toyota can explain why the same fluid is all of a sudden halved.

 

Thanks all who responded, appreciate that much.

I didn't know about the "smell" aspects, was just paying attention to the color alone. I'll check the smell and compare it with new ATF. I agree with most that at least by 50K miles it's not bad insurance to monitor minimally and perhaps change the ATF -- worst case I hope it wouldn't hurt and yes it doesn't take more than 30-60 mins.

Is the Toyota T-IV the only option or would it hurt if I try something like Valvoline Max ATF (the latter is supposedly all synthetic and compatible for T-IV)?

Thanks a ton !!

 

The Toyota T-IV is relatively inexpensive. BTW- it's one of the few things you can get from the dealer at or less $ than you buy it on-line. Unless you have some massively compelling reason to substitute ATF brands, I'd stick with the Toyota stuff. It's not something to experiment with in my opinion. Haya.....

 

My HL has been getting a new filter and ATF every 50,000 miles. The first 2 at the dealer, the 3rd by me. If you doubt you need to change it, you can send a sample off to an independent lab and have them test it, I've seen the results, and they aren't pretty. If you change it yourself, you will understand why you need to.

Most transmission mfgs, like ZF and GM recommend a change & filter @ 50-60K miles. Even though some of the car manufactures they sell them to don't tell the customers or their techs. If they did, then they would have to change them at least once under warranty.

BMW finally had to stop saying it was a lifetime fluid, mainly because a well maintained BMW's lifetime ended up being how long the tranny could go without failure.

I don't know much about Toyota transmissions, other than the fluid and filter are cheap, comparatively speaking. So I just do it, and then I won't lose sleep worrying about a $2,000 tranny bill popping up and blowing my beer budget. If I spend an extra $500 over 15 years of owning this beauty, then so be it.

I'm not going to debate it, it's been beat to death in other forums. I have an email from ZF for my 01 BMW, and I've seen the postings from multiple people who sent their samples out, that's enough for me.

 

Change it at 10K miles initial best case by then all of the gears have broken in and finished shedding excessive wear metal.

Well for a long time Toyota recommended draining and refilling ATF fluid every 15K miles. Then suddenly it never needs to be changed and is good for 180K miles and you only inspect it every 60K.

So if you have a dipstick and a drain plug I would stick with 15K miles if you are able to do it yourself. If not every 2 years 24K miles is a good idea. If you want to do the absolute minimum and hate yourself and your transmission than you should invest in Redline D4 and change it every 50K and change the filter every 150K miles!

You do not need to drop the pan and change fluid and I would never recommend that at 47K or regularly. Just pull the drain plug.

It has a drain plug and a dipstick. Get some transmission plug gaskets. Pick up 4 quarts of Toyota WS fluid or similar like ASIN WF or the like.

It will likely take slightly more than 3 quarts.