I carry a spare hub with bearings installed, new cap and lug nuts makes for quicker road side repairs.
Also spare spindle nut, washer, cotter pin, grease, tools modified to work on this stuff, small hammer, etc..
e.g. large pump pliers to wiggle the hub cover off.
All kept together in a dedicated in a tool box just for hub repair.
I know I have everything in one place because it is the same tool box I use for regular hub maintenance.
A bottle jack for getting trailer into the air.
A tarp (for working in the rain), 5-gallon bucket(stool).
I had too many roadside repairs, so replaced the axle last year (seals never sealed right)
I have a pickup truck for towing, so plenty of room for tools and parts.
Did I mention night light and Peppermint Schnapps?