Transmission Cooler # D13502 Routing Recommendation on a 2002 Chevy 2500HD

Question:

I have a 2002 Chev 2500HD with a 6.0 Lt. Engine and tow a 26’ trailer, about 7,500 pounds. I am looking at adding a transmission cooler in series with the small factory cooler, 11 X 5 X .75, to lower my transmission temp. On pulling grades I see transmission temps going up to 220-230 deg. at times. I am looking at using a Derale D13502. Is it OK to series up this with the factory transmission cooler? Thank You,

asked by: Gary K

Expert Reply:

Yes, you can run this Derale Series 8000 Plate-Fin Transmission Cooler Kit, part # D13502, in series with the factory transmission cooler that is on your 2002 Chevy 2500HD. A lot of people do this and it should help bring your transmission fluid temperatures down.

You will want to route the transmission fluid through the factory cooler first, and then through the # D13502, and finally back to your transmission.

Routing the coolers in that order is crucial, if you were to run the # D13502 before the factory cooler you would effectively be cooling the fluid and then reheating it as it would go through the factory cooler which will be the same temperature as your engine coolant.

You will want a Derale Radiator Adapter Fittings for GM, part # D13018, also to allow you to install the cooler without having to cut or flair any metal lines.

If you have room I would also recommend a larger cooler like the Derale Series 8000 Plate-Fin Transmission Cooler Kit, part # D13503.

I attached an FAQ article on transmission coolers below for you to check out also.