Question:
i have a 2007 jeep liberty with a 3.7l..wich cooler is better the tubes or the fins? After installing a cooler do we need to add more transmission fluid?
asked by: Steve
Expert Reply:
On a transmission cooler there are three basic types of heat exchangers. The most efficient is the stacked plate. The next one is the plate and fin, which is very efficient. Then, the tube and fin which is moderately efficient.
It will also matter where the heat exchanger is installed. The best spot for the greatest efficiency is between your vehicles grille and the AC condenser core on your 2007 Jeep Liberty. The next best spot is between the AC condenser and the radiator. This spot will reduce effectiveness by 25 percent. The last spot is between your engine and the radiator. This spot will reduce effectiveness by 40 percent. Using a larger cooler in the last two spots can help make up for the lost in effectiveness.
Transmission coolers are flow through devices so you can pretty much use any transmission cooler you want as long as it will fit in your vehicle. You cannot cool the transmission fluid too much so there is no worry of installing a cooler that is too large. The only precaution with a very large cooler is to let the engine warm a bit on bitterly cold days before taking off.
For your 2007 Jeep Liberty I would recommend the Derale Series 8000 Plate-Fin Transmission Cooler, part # D13501, or the Derale Series 8000 Plate-Fin Cooler, part # D13503. The # D13501 is rated as a Class II which is up to a gross towing weight of 3,500 lbs and the # D13503 is rated as a Class III which is up to a Gross towing weight of 6,000 lbs. You will just need to measure on your vehicle if you will have room for either cooler. I am including a link to both coolers that will give the dimensions of the heat exchanger.
The only additional amount of transmission fluid that is added would be the amount that will be in the hoses that will connect the cooler to the transmission. It is a minimal amount, like maybe less than a pint.
I am including a link to a FAQ page on transmission coolers.
expert reply by: Jeff D

Products Referenced in This Question
Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class II - Efficient
Product Summary:
Plate-Fin Cooler
With 11/32 Inch Hose Barb Inlets
Class II
Product Specs:
11W x 5-3/4T x 7/8D Inch
Standard Mount
Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class III - Efficient
Product Summary:
Plate-Fin Cooler
With 11/32 Inch Hose Barb Inlets
Class III
Product Specs:
11W x 8-3/4T x 7/8D Inch
Standard Mount
Product Page this Question was Asked From
Derale Series 9000 Plate-Fin Transmission Cooler Kit w/ NPT Inlets - Class I -Extra Efficient
Product Summary:
Plate-Fin Cooler
With 1/2 Inch NPT
Class I
Product Specs:
11W x 3-7/8T x 1-1/4D Inch
Standard Mount
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