silvertn35

I'm looking for a transmission fluid flow diagram. I know it flows from the transmission to the radiator and a side cooler . I installed an aftermarke cooler because I overlooked the factory cooler on the passenger side. So now I am looking to eliminate the side cooler. I attempted to look at the lines today but its rather confusing. Thanks in advance.

silvertn35

Ok after doing some research it seems that all RX300's come equipped with the trans oil coolers. The auto trans fluid doesnt seem to run to the radiator as a source of cooling just straight to the cooler located in the passenger fenderwell. According to the way I have mine setup hooked up , trans fluid flows out of trans to the OEM cooler to the aftermarket cooler then back to the trans. I think I am going to leave the setup alone right now as I believe the aftermarket one is more efficient. I might actually just switch it to only the aftermarket unit and remove the rather large oem unit. According to my knowledge though a remote location such as the oem with a small electric fan would prove to be very efficient.

This thread can be deleted as it is no longer needed. I will still think about what I want to do about my setup though.

code58

I don't know how much research you have done on trans. oil coolers (oil coolers period for that matter), but the factory aux. cooler that is in the R side ahead of the RF wheel is a much more efficient type cooler than the one you have installed as an aux. cooler. Placement is terrible but a much better cooler. If there were a way to mount a flat enough small fan in front of or behind the factory cooler so that the air ACTUALLY moved over it, it would be more than sufficient without the secondary cooler. The type of cooler that the factory used (can't remember what they call it right now) is so much more efficient that it doesn't take a very large cooler of that type to really do the job, as long as it has air flow. You virtually never see the factory using the type used as secondary anymore, because the other is so much more efficient.

Additionally, they run the trans. fluid through the aux. cooler 1st because they want the temp. moderated by the rad. trans. cooler, which under some conditions may actually ADD some temp back to the fluid, but more importantly, not dumping cold fluid back into a warm trans. in really cold weather. Better to cool the fluid, but keep it at a relatively even temp, which the rad. will do.

silvertn35

can you provide where it shows the fluid runs through the radiator? Because I cant see it on my diagram , even though I am certain it does. IMine shows it goes straight to the cooler and back. I'll give it a good look tomorrow in person and trace the lines myself. I never really thought about the cold fluid into a warm transmission aspect and I appreciate the heads up. I'm here to learn so I appreciate the info. I might look at removing my cooler then. I'll make a decision tomorrow after I take a good look at the lines and where they go exactly.

I've decided since the weather is still cold to uninstall it for the time being and let the factory setup work. I will be uninstalling it tomorrow, but I will break it back out this summer when it really warms up.By then I can make a definite setup that should be easily reversible for colder months.

georgie39

silvertn35
Have you been able to determine correct fluid flow through the trans cooling system?
The steel lines on my 2002 AWD RX are pretty well rusted and I want to replace them with new line or just scrap the steel lines altogether and go with 3/8" neoprene hose for the whole system.
Also, is the radiator in the circuit? Or on a AWD with the aux cooler does the fluid just go to the aux cooler and back to the trans? I may be wrong, however I've looked and cant see a connection to the radiator.
Any insight or input would be appreciated.