So I drove the bus at night for cooler air temps... I drove half of my 800+ return trip home. I'm not driving the second half til later in the week. The engine temp stayed around 180 unless climbing, then could go up to about 200.
The transmission temp, however, would spike even on short, or gradual, grades, and then quickly come back down as soon as I was back up to speed The downhill side.
The fan spins easily by hand when the engine is off, so it seems that it likely does need to be replaced. But here's my question: it's my understanding that the tranny uses the radiator and the fan to cool off, same as the engine. But if the fan is not designed to kick on until around 210 degrees... Well I never saw the engine temp get that high. But the tranny temp would be approaching 300 on the climbs.
Will installing a new viscous fan clutch help in cooing the tranny, or is there something else I'm not yet considering?