Hot Tractor

[Mark Page]

It was 93 degrees today when I was mowing. I had my feet on the running boards and noticed the clutch pedal, brake pedals and the transmission cover were extremely hot, I would guess around 180 degrees. The temp gauge was right where it should have been, in the green, and the tractor is new. What is causing the heat? Are geared transmissions supposed to run that hot?
Someone suggested that it's the bigger hydraulic pump than were in my previous tractors. I put my feet up on the loader mounts to keep from getting burned.
The loader was not on the tractor.

 

[Jerry/MT]

Mark,
These tractor gear trains are like 85-90% efficient. That means that 10-15% of the power goes directly to heat via friction. The drive train oil gets warm and that gets the casting warm. If you start out with the tractor at 93°F it will just get hotter the more you use it. Now it won't heat up and melt because there is some heat transfer from the casing that limits the upper temperature but the hotter the day,the heavier the work, the more power you apply, the higher tamperature you'll see. Additionally the rear axle fluid also goes through a hydraulic pump with maybe 70% efficiency (a guess on my part for efficiency) so that fluid also gets heated by the pump and the rear axle gearing, planetary drives etc. I don't think it's getting to 180°F, however but without some data I can't prove that.
So keep your eye on the engine temp gauge and make sure that it stays in the green band and you'll be fine.

 

[k0ua]

Wow, that seems pretty hot for geared tractor, Hydro's get pretty hot, but they have a cooler in front of the radiator to deal with it. I am betting it wasn't actually 180 degrees, but maybe was.. How about getting one of those remote infrared temp guns and finding out... they have one at Harbor Freight for about $25. It would be interesting to know. I changed a tire on the car tonite in full 100 degree heat and full sun, the tire was so hot I felt it might burn my hands. I let it set for a bit to hopefully cool off but in the sun, I don't think it cooled much. I threw it in the back of the car as fast as I could.

James K0UA

 

[MHarryE]

I had a machine that had a very hot platform due to the direction we were sending the cooling air after it had gone through the oil cooler and radiator. I installed several thermocouples on the platform to see how bad it was and while my feet ere being toasted and everything felt extremely hot, the thermocouples never went over 125. Of course that is too hot, even for an 85 degree test day, so we redesigned the cooling system. Point is that something can feel a lot hotter than the actual temperature. Gears do get hot. I've used 225 as the limit with mineral oil and 250 with synthetic.

 

[Guesseral]

Where does your exhaust pipe run. I noted the other day my left running board was really hot but the exhaust pip runs under it so I assumed that was it. Yea I know that's probable a stupid thought!