I was reading some posts about weather to pack the rear bearings or not. Some people said they were lubricated by the rear end oil and not to pack them. On the F2/3 there is a tight fitting slinger that touches the outer bearing. The chances of gear oil over getting to the bearings, especially the inner bearings, is nill. The fill plug is also way under the level of the axle tubes. Pack them!

 

You don't want the axle fluid higher than the axle tubes as that will pretty much cause the axle seals to leak. Are you sure that is an oil slinger in there? I've had two F-3 axles apart and many other full floaters with no oil slingers.

Also the oil gets to the bearings by the axle shafts. When the axle turns it gets oil on the shaft which runs down the length of the axle to the hub. Some oil will fall off the axle and go down the tube also.

Greasing the bearings is a safe sure method of lubricating the bearings till the oil gets there. If the vehicle is going to see immediate use soaking the bearings with gear oil will also work. Just don't put them in dry.

 

Its a grease/oil slinger (4345)for sure and there is no way in hell there would be the proper amount of oil to lubricate the bearings. This slinger is a very tight fit into the hub. Think about this: if the oild runs down the axle into the hub for the bearings, how does it get back to the rear end?

 

The oil doesn't need to get back to the rear end. The oil will fill up to the axle tube and any excess will run back to the carrier.

 

If you mean 4245, it is on the outside of the bearing, will not prevent oil from reaching the bearings.