I blew my tranny awhile back will thought I did ending up being a bad pressure sensor but got a rebuild anyway before I realized it was just a sensor. I put the suncoast extreme rebuild kit, ats flex plate, ats 5 star convertor, transgo shift kit and a derale cooler mounted under the bed. What is the normal operating temp of a 48re I've been told by the dealer its around 190-200 degrees seems kinda high to me and others on the forums so they are seeing nothing over 160-170 with the same derale cooler so where is it supposed to run? I can't even drive mine very much in the city cause it get hot around the 200-210 mark and it doesn't stop climbing then its starts acting funny and I have to let it cool off. What could be some causes of it getting that hot? Any help would be much appericated.

Sent from my HTC Sensation 4G using Tapatalk 2

 

Are you sure the cooler is flowing properly?
There is a check ball in line that can stick and it will kill the trans by restricting flow. Better check it out.

 

Where is the check ball located?

Sent from my HTC Sensation 4G using Tapatalk 2

 

170 - 200 degrees is certainly within norms. I have been a mechanic for almost 40 years and have seen temperatures very between 30 - 40 degrees depending on vehicle type and also guages. I would worry if temperatures were getting up around 230-240 but you might want to check your temperature using a different method than what you are using just too make sure you are getting the correct reading. I use autometer guages myself but I also have and infrared meter to make sure they are reading fairly accurately. My truck tends to run in the 170-190 range normally and when I pull an 18000 pound trailer it gets up to around 225 when pulling a hill but also cools down again when pulling on a flat surface. Just for a reference my truck pulling my trailer up a 7 degree hill for approximately 3 miles at 50 mph and 2000rpm will go from 190 - 225 and then it takes about 10 - 15 minutes to cool down again. I travel this hill atleast 3 - 4 times a week.