The differential in my car has Eaton truetrac, a temp gauge and cooler. I bought the car in November and haven't really driven it much. I drove it on a 20 mile ride on the highway to work and the diff temp gauge pegged over 250 (definitely too hot). So, on the way home I turned on the diff cooler and it got up there too. I don't think the diff coolers working. But at regular highway speeds I shouldn't need the cooler anyways. I saw a puddle under the back the next day so I figured it had a leak from the cover and the oil was low. I ordered the FTBR kit (might as well while I'm there) and took the IRS out. Turns out the cooler pump was leaking. Not the diff cover. When I drained the diff (without measuring) it looked like it had enough fluid. Now that the diff is out, what can I check to figure out the cause of this heat? I'm not gonna race the car and I want to remove the diff cooler, and eventually the temp sensor too.