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Spindle pullies hot... normal?

9388 Views 14 Replies 7 Participants Last post by  jgayman
Since I've been mulching leaves with my X500 & 48-inch deck, I removed the plastic covers over the two outer spindles. This allows easier removal of the leaf debris.

I noticed that even on a cool day the outer spindle pulleys are very warm to the touch after running for only around 5-mins. After a mulch session they are too hot to touch.

Is this normal?

Obviously I was never able to touch them prior to removing the plastic covers.

I could see them getting hot after 1-2 hours mowing but the fact that they were warm after only 5-mins has me puzzled.
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The friction from the drive belt entering and leaving the pulleys can warm them up pretty quick. More load on the mower blades means more horsepower handled by the belt and pulleys which adds to the heat load, as will the heat from the spindle bearings under load.

Add it all together and there is a lot of heat involved, and not a whole lot of airflow for cooling.
Thanks! That was my initial theory as I figured there was no way the bearing itself could generate that much heat - and keep working. :)

I appreciate the confirmation.
You keep them greased, correct ??
Yes - regularly.
I can just imagine what the bottom of the deck looks like.
Same here. I use the leaf blower to clean the deck and tractor after every use.

I had been keeping my plastic spindle covers on and while the leaf blower gets most of the crap out from under them, I finally wised up and removed the covers.
Umm. I suggest that you revisit your figuring. Those shafts turn at 3000+ rpm and the belt puts a substantial side load on the shaft when the blades are working hard.
I agree. I know bearings can get hot.

I should have said "generate that much heat in that short of time". :) I understand how bearings get hot under heavy use. When I noticed the pulleys were warm I had only run the deck for about 3-mins.

I figured there was no way THAT much heat could be transferred from the bearing up through the shaft to the pulley in only 3-mins. If the bearing was generating THAT much heat it would be cherry red and smoking after mowing the yard. :)
The one thing I like about mulching leaves. It shines the mower deck up underneath. I probably couldn't do much better with a sandblaster. I took a piece of 22 gauge sheet metal and formed it to fit over the chute opening. It helps keep the leaves inside longer to chop them up. Usually I see two little deposit trails under the mower deck.
X2 ! I was planning to take my deck off at the end of the season and clean it up but after mulching leaves it is clean as a whistle. There is not one spec of packed grass anywhere... even the nook and crannies are clean! :)
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