Huh? Now I'm really wondering. It doesn't really matter because I know mine are sealed, but now I'm half tempted to run back to the auto parts store and do a comparison between the two in person. Odds are I won't but if I'm in there I might just ask to see the others for ***** and giggles. Then again OPT the pics on Amazon may be kind of a generic pic and not what you actually get.

 

Well for anyone who cares I solved the mystery. At first glance with the two different bearings side by side they are identical in every way with one exception. The 510013 that I purchased can be taken apart from each side and repacked. The 510003 will not come apart, and in every way that I can see they are identical to the polaris oem except for the fact that the oem's are china made where as the federal mogul's are U.S.A On another note, I asked and found out that the bearings I bought (510013 repackable) were $10 cheaper than the 510003. I don't know if one would be better than the other but I would think the repackable bearings would be better suited for ATV use since they do see a fair share of dirt, mud, water,etc.

 

Good info to know and tucked into the "someday might be handy info" file. Thanks for posting what you found out.

Fred