Kobalt 80V 21" Electric Lawn Mower Rear Wheel Bearing Replacement Two years and one of the rear wheels started to wobble. After removing it, I found that the inner ball bearing was completely destroyed (no more balls in it). I've searched the internet for a spare wheel, but to no avail. So I measured the existing bearing housing dimensions and this was the closest I could find. Fits almost perfectly, just added a small paper spacer on the outside to create a better fit in the plastic wheel hole. Now the wheel spins much better than the ones with the original bearings but there are 3 more in the pack so maybe I'll replace them all.