Replacing the OEM Transmission Cooler with an Aftermarket Cooler on a 2005 Nissan Pathfinder LE 4.0

Question:

Ive been reading online of all the issues the R51 Pathfinder has been having with radiator fluid leaking into the ATF. Would this particular cooler fit in the 4.0 Cycl enginer bay and possibly prevent the issues people are seeing or is there another model that works better. Im assuming this is better than also replacing the radiator as the problems might return.

asked by: Nimit N

Expert Reply:

The Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class III - Efficient, item # D13502, could be used to replace the original ATF cooler in the radiator on your 2005 Nissan Pathfinder LE 4.0 liter.

I would recommend four things. First, measure to be sure that the cooler you select will fit in front of the radiator or air conditioning condenser on your vehicle.

Second, select the largest capacity cooler that will fit in this area. The largest 8000 series transmission cooler we carry at this time is the Derale Series 8000 Plate-Fin Transmission Cooler Kit w/Barb Inlets - Class IV - Efficient, item # D13504. Which is 11 inches Wide x 12 inches tall x 7/8 inches deep.

Third, use a Remote Transmission Filter Kit w/ Temperature Gauge, item # D13091, so that you can monitor the transmission fluid temperature and change the fluid filter easily. Transmission fluid cannot be cooled too much, and should not exceed 200 degrees at any time.

Fourth, make sure that you plug up the original fittings in the OEM transmission cooler. Normally this might not be a concern, but since there is the possibility of anti-freeze leaking into the transmission cooler you will want to be sure that, if this occurs, all of the antifreeze would not be able to leak out and cause the vehicle to overheat. You will need to get the proper size plugs from a local hardware or auto parts store.