My John Deere 8970 has been running hotter than usual this spring … so yesterday, it got hot enough to activate the red stop engine light. I’ve triggered the temperature with one of those guns and it’s getting too hot. That removed the temperature sensor. The fan seems to blow air, but maybe not enough. I can run for about 10 minutes and then it’s too hot, but if I stop for a minute or so it cools down again. Fan clutch Thermostat is in place.
A new fan clutch will solve your problem. I struggled with this when I first got my 8960. I didn’t want to spend the money to change the fan clutch either, so I tried everything I could think of. I replaced the fan clutch and had no problems again. I know a couple different guys who tried to screw it solid. It worked fine, but it ate the fan belts every 3-400 hours. The fan clutch should fix it.