QU40243 Outboard Axle Shaft to Axle Housing or Spindle Seal is a genuine original equipment Seal that presses on your Ford Excursion or 1999-2004 Super Duty inner axle shaft next to the yoke. QU40243 was also used on 1988.5-1997 F-350 and 1993-1997 F-250 trucks as axle shaft to spindle seal. On the inner shaft, It's function is to keep dust and debris from entering the axle housing tubes. For inner axle shaft applications, this is only a Dust Seal. If you see oil leaking past this seal, you need QU40244 Inner Axle Seal. Fits both Dana-Spicer Model 50 and Model 60 Front Drive Axles. Made in U.S.A. or Canada. Order 2 Seals per vehicle.
To maximize dust seal life and prevent squeaks, apply a thin, uniform coat of a quality grease to the seal lip.
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.
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.
1988.5-1997 Ford F-350 (partial):
All 1999-2004 Ford F-250, F-350, F-450, and F-550 4x4 trucks
All 2000-2005 Ford Excursion 4x4s