2000 Rav 4 - 226,000 Mi.

[anchorman]

I just don't follow the repair garage's logic. My gearbox is sealed for life but I think I would probably change it before it gets to a sludgy mess. An auto box is full of wearing parts so I would expect some discolouration with time. There will be a filter. If I was going to do the oil I would clean it at the same time.

I can give you instructions from the manual if you like.

[firemac]

"I'd like to think that Toyota had planned for the inevitable need to change the oil and it'll all be fine!"

I wouldn't count on it. I wondered about changing the ATF a couple of years back and when I approached my dealer with the question, all I got was a stupid, blank grin. They couldn't find anything in any of their service routines or bulletins.

After some debate on this forum, the consensus amongst the gurus hereon was that unless I was operating in harsh conditions or the box was not behaving itself, it was best to leave well alone. So far, that has proven to be good advice.

Nevertheless, I can't believe that a reputable autobox specialist couldn't flush the box effectively and refill with confidence that there wouldn't be any nasties left lurking about in the galleries. After all, there are quite a few classics with slush boxes that must have had their ATF changed, probably more than once, over the years.

Or am I hopelessly naive??

[DjRav]

You're as confused as the rest of us, you post even disagrees with itself!

Dave

[Big Kev]

Me......? I now have a great view of my tonsils, as my head has disappeared up my bottom based on this. No way in creation will I allow the ATF to become so dirty that there is a doubt as to whether to change it or not. Most liquids are to some degree hygroscopic, and we all know what water does, que....? Yep....ruins yer whisky......

Ah cannot believe the amount of people now Googlyfying "non hygroscopic liquids...."

[mcummo]

I had met today with a reputable transmission shop that has been in business 32 years. My brother has been doing business with them for decades and can vouch for them. Owner basically agreed that as long as things are running smoothly to leave it alone.

Seeing that the consensus in the community is the same, I am going to enjoy my ride until I start having trouble.

Thanks for all your input - mcummo

[ANNAWONG]

Some nonsense on this thread!

Would you run an engine for ever without changing oil? No, I thought not, then why would you a transmission, (manual or auto)?

It's the same with diffs. Some say leave alone, some say top up, others advocate change at intervals.

For what it's worth, in America, Toyota recommend 20,000 mile oil changes for Rav 4 auto boxes, (which need Dextron 4 with additives!) and for the front transfer box and the rear diff, 24, 000 miles.

That's what I do and it works for me !

(I have spent my life in engineering, with dignostic tribology in the main, dealing with rotating mechanisms in all sorts of stuff from submarines and fighting ships, through to cranes, excavators, helicopters, process mechinery and much more. The idea of NOT carrying out oil changes at prescribed intevals with that lot would be ridiculed as being ludicrous, by all involved.)

Why would it be any different for a RAV 4?

So take your pick, I rest my case.

[mcummo]

Thanks ANNAWONG;

My problem is that: the only record we have for changing the transmission oil is 100,000 miles ago.

We have no way of knowing otherwise.

Toyota won't change it stating that they have had other similar situations that have resulted in trans failure.

I've gone to transmission shops and they also advised me to leave it alone.

[DominicPriestley]

Nobody is questioning that regular oil change is best practice. Problems arise when the oil has been in situ for a looonnngggg period of time and is changed. This can induce failure where leaving the oil in situ would not.