Transmission Cooler Recommendations for a 2003 Toyota 4Runner

Question:

I have a 2003 4runner 4wd limited. I see all these blogs about upgrading the transmission oil cooler. Does my vehicle come with one stock and is it necessary? I do not tow often but would like to make my transmission last as long as possible. Also, how often do I need to change my differential oil and transfer case oil? I just bought the vehicle and do not know it they have been changed. I would like to change all the fluids but do not know if I should. The vehicle has 135k. thanks is advance

asked by: Jeffrey V

Expert Reply:

First, the maintenance schedule for your 2003 Toyota 4Runner can be found in the owners manual. It will vary from vehicle to vehicle but unless the fluids have been changed frequently then they are probably about due.

Vehicles have a factory transmission cooler normally built into the radiator. Adding a supplemental cooler is a good idea because the fluid cannot be over cooled and keeping the temperature lower will extend the transmission life.

The most popular transmission cooler option for a 2003 Toyota 4Runner is # D13503. I have included a link to a video that shows a typical installation. I have also included a link to some FAQ articles on transmission coolers for you.

expert reply by: Michael H