So in my truck, if i am in a looooong down grade with the trailer fully loaded on the back of the truck and i use the truck to slow me down, i will have issue with the trans overheating. this ONLY when in a down grade situation and i am running 3500-3700rpm to slow my rig down hill. I can watch coolant temps drop to the point they close, EGT's in the 200-250* range, Oil temps in the 180* range and basically everything cooled off ACCEPT the trans. initially it will cool from 210 or where ever i am about 10-15*, they temp starts to raise about 2/3 the way down the long grades im on. it did this wtih my old radiator and stock air to oil cooler and it has now done it with my Setrab cooler from Mike and the new radiator.
What im figuring is going on is the thermostats are closed so fluid is no longer circulating and now the water around the heat exchanger is heating up with no place to go so the trans starts heating up. the fan isnt on either so no air coming across the trans cooler at 50-55mph. Now when i run my solid hub, it may help but im wondering if anyone has tried running a 160* race thermostat in one spot and a 185 or 180* thermostat in the other. i figure ill run the 160 in the water pump bypass area so the pump will continue to circulate till temps drop below 160. i figure this way, the other higher temp thermostat will let me get up to a semi decent temp still so i have heat in our "cold az winters".
thoughts? wonder if id have too high of coolant pressures from the water pump if the 185 or 180 isnt open yet? though i figure that would have shown up as an issue already with the WOT cold runs i did years ago trying to set the rings in
What im figuring is going on is the thermostats are closed so fluid is no longer circulating and now the water around the heat exchanger is heating up with no place to go so the trans starts heating up. the fan isnt on either so no air coming across the trans cooler at 50-55mph. Now when i run my solid hub, it may help but im wondering if anyone has tried running a 160* race thermostat in one spot and a 185 or 180* thermostat in the other. i figure ill run the 160 in the water pump bypass area so the pump will continue to circulate till temps drop below 160. i figure this way, the other higher temp thermostat will let me get up to a semi decent temp still so i have heat in our "cold az winters".
thoughts? wonder if id have too high of coolant pressures from the water pump if the 185 or 180 isnt open yet? though i figure that would have shown up as an issue already with the WOT cold runs i did years ago trying to set the rings in