Dan the Gear Man® Tech Note 1:
To maximize dust seal life and prevent squeaks, apply a thin, uniform coat of a quality grease to the seal lip.
Dan the Gear Man® Tech Note 2:
These seals are a fairly light friction fit on your inner axle shaft. The only special tool you need to install these are your two thumbs to push them on. If you do not install your axle shaft right away, you may find the seal has "popped" off the shaft shoulder. This is normal. Just push it back in place and install the axle shaft. Once installed the seal will stay on the shaft.
Dan the Gear Man® Tech Note 3:
This type of Outboard Axle Shaft Seal has a fairly short life. Most of them will be worn out within 3 or 4 years. Since they are just an outer protective seal, a failed one does not pose any real problem, although it is of course better to have them functional.
Dan the Gear Man® Publication Reference Note:
QU40243 is item 22 in the Shaft, Hub, Brake, and Steering Components Full Color Exploded View that is included in these 4x4 Tech Publications: TSB4644, TM4637, and TM4688.