The trip home was a different story. Much hotter weather, still pulling the camper. My ambient temperature sensor has been relocated to a better place and always reads between 2-3º of ambient air temp as reported by my Apple Watch. Anyway, ambient temp according to the truck (full sun on the highway) was high 90s for most of the trip, with a few peaks into 100-101ºF. We were on I-64 westbound between Norfolk and Richmond and the transmission temp hovered around 207ºF with the coolant temp staying around 210ºF. We hit some stop and go traffic and the transmission would peak around 215ºF once we got going and I saw the coolant hit 230ºF a couple of times on some longer grades at 65-70 mph. We pulled off the highway to get to the house and the transmission temp peaked at 232ºF with all of the traffic lights, while the engine coolant dropped to around 200ºF. By the time we got to the house the transmission had settled to around 225ºF
Net/Net, the transmission stays cool on the highway until it has to do a lot of shifting in traffic (to be expected), and there is a time lag of 5 minutes between pulling off the highway, and maximum transmission temp in traffic before it starts to come down again. The coolant runs a little warm on the highway until I get off and it cools down quickly. I'm not getting the cooling from the Derale I was hoping for. It's less effective than the Tru-Cool was.
Next steps: 1/ Fix the baffles beside the radiator permanently with some coroplast. When I got home I noticed my temporary repair had failed, so that should help the coolant temps on the highway. 2/ Fab up some deflectors from sheet aluminum to increase ram airflow to the Derale, since it's mounted behind the license plate. I also noticed that the Derale fan started making some noise, so I will investigate that as well.
The weekend after next, I'll be running the same road that saw my transmission temp hit 265ºF before I rerouted the transmission cooler lines through the radiator. We'll see if plumbing the radiator cooler back into the system really does anything to shave off those higher temp spikes.
Gotta get this thing 100% dialed in before mid August when we hit the road for Yellowstone and the Tetons.
Good info.
I'd love to take my family on one of these trips. Can you link me to some good resources for newbs? Good spots to go etc?
