Hi,

I'm trying to install transmission cooler on my AWD IS. And I found there is already a thread (https://www.clublexus.com/forums/is-...-cooler-3.html) talking about it but didn't give a solution. It did mentioned that the IS has transmission warmer instead of cooler. And based on diagram I found, the coolant hose from transmisson goes to engine instead of radiator. And it seems like some of our models (IS500 I found) has transmission coolant goes to radiator.
However, my radiator doesn't looks the same as the IS500 diagram, mine only has 4 holes. 2 big ones for in & out, 1 bleeding, 1 reservoir.
This diagram is closest I can find to my radiator.



And this diagram is for the IS500 transmission cooler.


And my questions are:
1. Is IS500 radiator thicker than IS350 (v8 vs v6)?
2. Can IS500 radiator fit IS350?
3. How does the line go between transmission, radiator and extra cool?
4. Is there a pump keep the flow of coolant?

Any help, tip would be awesome!

 

Your questions are a bit difficult to answer, mainly because we don't know what your goal is.

Is your transmission overheating? If it is, what are you doing to cause it?

I wasn't able to overheat the engine or the transmission on my supercharged RC350 here in phoenix Arizona with temps over 115 for the last 30 days in a row. The only time the car started to get warm was with heavy track use and beating the car up lap after lap. after 20 mins, the car finally started to get warm, both the transmission fluid and engine coolant.

There are better solutions for oversized radiators and transmission coolers for these cars, check Mishimoto.

RR-Racing said that they installed one on a 350 before, but there wasn't any demand for it, being most people who track their IS/RC/GS typically own the 'F' Variant, not the 350. It never hit the market.