Transmission cooler fitment

[GeeWhizz Senior Member Find all posts View Profile Close GeeWhizz]

Is it? I thought the manual(s) doesn’t make direct reference to particular intervals?

Go to the pages toward the back of the Maintenance/Servicing book. "R" for replace.

[DirkZ Lurker Find all posts View Profile Close DirkZ]

My mechanic mentioned during a service about 2 years ago that my transmission fluid was bad and needed replacing. And when I started towing a caravan I read on a Prado group about the scan tool and how to check your ATF temperature. I saw that the temp was quite high when towing in Drive. I want my Prado to last and decided to get the ATF cooler which definitely brought the temp down a lot. Initially it was higher than the engine temp, but now it never gets close to it. So very happy now and can recommend the Koan transmission cooler. Just my experience for what it's worth

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

Tow in 4th and go to drive downhill or with strong tailwind

[Piggy Water pistol pilot. Find all posts View Profile Close Piggy]

Reduced from what, Piggy? What's the reference temperature? I'd have said that on flat terrain when not towing and in temperate conditions, 88° was what the ATF eventually stabilises at. What's the source for those quotes?

From one of Australia's well known Trans specialists.

We have also had oil/ trans fluid samples taken from various fleet vehicles including the Prados and sent off to the lab for analysis, and oil life is pretty well spot on to what he says. Yes, you can leave the oil in longer but is it good for the components? Not really.

Bottom line is: Oil breaks down quicker when it's been run at higher transmission temperatures. EG, Someone who gets the Trans oil temp light comes on a couple times, Should be looking to replace that Oil asap. If the oil has been in the car for ages, then damage will be done quicker.

[Daniel150 Member Find all posts View Profile Close Daniel150]

Piggy is correct with the trans temps to mileage ratios.
Toyota have always said “sealed for life” since the asin 750f in the 120. That is complete rubbish. It’s more like a “sealed until warranty runs out”.
In the owners manual it states that you should change it at 80k if using under extreme conditions. Most Toyota techs will tell you “nah, sealed for life” if you ask for a flush, even at 150k.
Optimum temperature is 80-90 degrees for trans temp. As piggy showed, if kept at 90 degrees, you will safely run it for 80k. Mine usually sits 90-100 when towing with times up to 110-120 on soft sand. Therefore I choose to service it every 40k.
Most trans places will sugggest about 50k services regardless. I feel they are the ones who have an interest in looking after the trans. Toyota have an interest in giving us the cheapest possible service price and a trouble free warranty period.