Recommended Transmission Cooler and Locating Transmission Return Line on 2007 Chevy Avalanche

Question:

which trans cooler to use on a 07 avalanche 5.3 and which cooler line is the return top or bottom? Thank you

asked by: Rich

Expert Reply:

The return line is typically the bottom line, but you should confirm by doing the following.

Start cold engine, place the transmission in drive for about 10 seconds, then shift back to park and shut motor off.

Then, feel the upper and lower transmission lines. One line should be noticeably cooler than the other. The cooler of the two lines would be the return.

Since you cannot over cool a transmission, we recommend choosing the largest cooler that will fit into the space available. The ideal place to install a transmission cooler is directly behind the grille, in front of the A/C condenser.
Since the transmission cooler is a flow-through device, it will not obstruct the A/C condenser or radiator.

If the space is available, I would recommend the Derale # D13504. If your transmission line fitting is held into the radiator with an e-clip, you will also need the # D13035 snap-in fitting.

I have linked you to our transmission cooler FAQ articles. To see them, click on the provided links.