Gents,
The part in question is a National Seal #40566. �Can't remember where the darn thing goes and I'm currently typing with my dunce hat on.... I'm fairly certain it seals the hub shaft so wheel bearing grease doesn't get flung around in the brake drum. �I thought these went with my locking hubs because I usually keep parts sorted like rabid librarian on speed and these ended up in my container with my DualMatic Lockouts. �Classic case of not remembering how to put the lego castle back together. �I'm not going to get into how many times I pulled the front and rear drums today, it was embarrassing. �But they fit the rear hubs and seem to be a fit for the front hubs also.
I took a pic next to the lockouts for comparison....
