4L60E temp and sensor location
I'm sure by now everyone has heard or asked about towing temps and sensor locations on the 4L60E transmission. I currently just added a 3rd tranny cooler to the factory radiator cooler and the fa...
Forum Discussion
You really want to know bulk temperature in the transmission sump/pan. If you place the sensor in transmission out as Bessie-Hunter recommended you will be measuring the temperature coming out of the torque converter which is the hottest oil in the transmission.
From a plumbing stand-point the in-take transmission cooler in the radiator should be the first cooler you flow through, than your oil to air coolers, then back to the transmission. If you flow the air to oil first you run the risk of actually heating your transmission fluid back up in the in-tank cooler. If you are running two external coolers I would be a bit concerned about the pressure drop in extreme cold, if you get an air to oil cooler cold enough (i.e. -30 to -40 fahrenheit you can get enough pressure drop that oil will not flow through the cooler. I am not overly familiar with the 4L60E but taking a quick look at the hydraulic I do not see a pressure bypass valve for the cooler circuit so if you get too much restriction in the coolers you can cut-off cooler flow.
What fluid are you running in your transmission? Newer fluids are more thermally stable (i.e. Dexron VI is more thermally stable than prior generations of Dexron). Older vehicles without a thermal bypass valve will run cooler unloaded than modern automatics (150 - 170 fahrenheit). Under heavy loads peak temperature should never exceed 248 fahrenheit. Towing on flat ground a stabilized temperature of 200 fahrenheit is acceptable, particularly if you are running Dexron VI.
From a plumbing stand-point the in-take transmission cooler in the radiator should be the first cooler you flow through, than your oil to air coolers, then back to the transmission. If you flow the air to oil first you run the risk of actually heating your transmission fluid back up in the in-tank cooler. If you are running two external coolers I would be a bit concerned about the pressure drop in extreme cold, if you get an air to oil cooler cold enough (i.e. -30 to -40 fahrenheit you can get enough pressure drop that oil will not flow through the cooler. I am not overly familiar with the 4L60E but taking a quick look at the hydraulic I do not see a pressure bypass valve for the cooler circuit so if you get too much restriction in the coolers you can cut-off cooler flow.
What fluid are you running in your transmission? Newer fluids are more thermally stable (i.e. Dexron VI is more thermally stable than prior generations of Dexron). Older vehicles without a thermal bypass valve will run cooler unloaded than modern automatics (150 - 170 fahrenheit). Under heavy loads peak temperature should never exceed 248 fahrenheit. Towing on flat ground a stabilized temperature of 200 fahrenheit is acceptable, particularly if you are running Dexron VI.
