Just bought a replacement Yukon shaft from Randy's Ring & Pinion for a 1977 F150 housing. It came with a set of Timken set 20 bearings and retainer like in this pic...

http://www.completeoffroad.com/images/cat/AxleBearing-9Tapered2095627691.jpg

These are very different from my original bearings. The seal for these is installed on the shaft before the bearing. The bearing is a unitized design and the outer race is not removable. These are rather spendy compared to a regular set of tapered roller bearings. Are these supposed to be better?

For installation, I presume that you first install the seal on the shaft, then the unit bearing, then the retainer. So what about installing the axle into the housing - do you just let the retaining plates pull the bearing into the housing, or do you tap the axle (with bearing installed) into the bearing end, then install the retaining plate?

I have read some threads about leakage with these type of bearings and seals so I don't want to screw it up.

Thanks.

Well, I guess I have to answer my own post. I just talked to a tech guys at Randy's. Apparently this type of bearing is better at handling side loads than the original tapered roller bearings. It is installed as presumed above. It doesn't really matter if you tap it into the bearing end or let the retaining plates pull it in.

They are actually the same bearings. I thought the same thing (WTF?) when I had new ones put on my axles. When you remove the axle the next time, they pull apart and look like the old ones. They _aren't_ unitized. just remove the race(s) and tap the new shaft in..

Well, I guess I have to answer my own post. I just talked to a tech guys at Randy's. Apparently this type of bearing is better at handling side loads than the original tapered roller bearings. It is installed as presumed above. It doesn't really matter if you tap it into the bearing end or let the retaining plates pull it in.
Its had for me to tell by the pic because the seal is in the way, but 9 inches had 2 styles of bearings, a Roller/ball bearing, and the Taper bearing.
The taper bearing are better in every way.