One front axle harder to turn than the other?

Hey everybody, I noticed something strange on my truck and was wondering if you guys had any idea whats up. So today I took the front tires off of my taco to clean the brake calipers and disks. Once I removed the calipers from each side and started cleaning the disks and hubs I realized my passenger side axle was much more difficult to spin than the drivers side. Is this something I should investigate further? I did notice what looked like an excessive amount of dirty grease that had been slung around the drivers side (loose one) but I couldnt tell where it origionated from and assumed it was from an old repair.
The entire front was on stands, in 2wd, and in park. Ive never experienced any abnormal vibrations other than from my severely out of balanced tires. Any advice would be great. Thanks

 

manual hubs?

 

yeah. both were turned to the free position