2001 F350 7.3 Powerstroke Best Auxiliary Transmission Cooler D13105 vs D13504

Updated 03/17/2026 | Published 03/10/2026

Products Featured in This Question

Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class IV - Efficient

(873)

$120.43

Derale Series 7000 Tube-Fin Transmission Cooler Kit w/ Hose Barb Inlets - Class IV - Standard

(22)

$107.68

Question:

D13105 or D13504, which will offer more cooling, stacked plate or larger face area ? It would be used with the factory cooler, so either would work, but might as well get the best one. Temps are not terrible anyway. 2001 F350 7,3 PSD 4x4 towing 12K 5th wheel

asked by: Bill

Expert Reply:

Hi Bill, if you are looking for the most cooling between those two, I would go with the Derale part # D13504. Even though the part # D13105 has a larger face area, the D13504 is a plate and fin style cooler, and that design is generally more efficient at pulling heat out of the fluid than a tube and fin cooler of similar size. So if your goal is to keep temps steadier on long grades while towing your 12K fifth wheel, the D13504 is the better choice.

Since you are keeping the factory cooler in place, the typical best practice is to plumb it in series so the fluid goes from the transmission to the factory cooler first, then through the aftermarket Derale cooler, then back to the transmission. That way you get stable temps year round and the Derale cooler works as the final heat drop after the factory cooler has already done its part.

What trips are you planning this season with the fifth wheel, and are you running a trans temp gauge on that 7.3 yet?

expert reply by: Heather A

Bill

3/12/2026

Temp gauge/sender is screwed into the test port on trans, so reading may be questionable. Still, as I remember high peak was 190, so not terrible. Upgrading/adding addition cooler, even if not really needed, is a minor expense, compared to cost, time, and inconvenience of losing a trans on the road or even replacing it at home. Also thinking of adding a finer filter as long as I am breaking into the loop. Thoughts ?

Heather A.

3/13/2026

@Bill I definitely understand that! A cooler is cheap insurance compared to a new tranmission. My transmission has been slipping in my Dodge Journey and I have a feeling it's going to cost an arm and a leg soon. Adding the D13504 in series is not going to hurt anything and should help the fluid recover quicker after long pulls or slow climbs. A finer filter can be a smart move. Just make sure it's a quality inline transmission filter designed for the flow rate of your system. Are you mostly towing in the mountains or more long highway runs?

Steviec

3/13/2026

Bill I've had an excellent experience with the D13504. I tow my 31 ft. Crossroads with a 2017 Chevy Suburban with the 5.3 ltr. engine. It has never gotten above 190/195 degrees.

Heather A.

3/17/2026

@Steviec I really appreciate your real world feedback Steve! That’s awesome feedback especially with a 31 ft Crossroads behind a 5.3, that’s no small load.

Ralph

3/13/2026

Installation was easy and placed in front of AC condenser. My 2009 Tahoe did not have a factory installed transmission cooler and often ran between 185 and 200 degrees. Now it runs about about 140 degrees in summer but runs too cool in the winter baily getting over 130 degrees in stop and go traffic and 110 degrees at highway speeds. I am actually thinking about replacing the cooler with a smaller one. It did go up to about 160 when towing a 3500lb boat.

Jeffmod

3/13/2026

@Ralph After adding my D13504 in our 2019 Suburban,(installed by my mechanic) with 5.3 ltr V8, my temp guage moved from a 12:00 noon normal position, over to a slightly cooler reading around 11:00, when either pulling or not, our 5800 lb tandem axle 20’ camper. I feel it was well worth it