Wanted to share my experience with this job and thought this would be the best place to post it (let me know if not and I can move it to a seperate thread).
To do this job I got the
Non-ABS Ultimate Rear Wheel Bearing Kit from Low Range Offroad. I've gotten lots of things from them and trust the products/kits they sell. Seperately, I purchased 2 more Toyota retainers from my local Toyota dealership in anticipation of reusing the ABS tone-ring but not the existing retainers. The Low Range Offroad kit comes with everything you need to do one rear axle: Nachi bearing, retainer, snap ring, outer dust seal, O-ring, and what they describe as "special lipped inner seal for easy install and heavy duty sealing ability".
It was this last item, the seal, where my confusion came in when installing this kit. They do make
an ABS version that includes a second retainer and an ABS tone-ring. This kit includes, as they describe, a "rear axle seal (Genuine Toyota UPDATED DESIGN)". This seals differs from the Non-ABS version that I purchased.
Once I got everything pressed on, with 5mm of polished axle showing, I got setup to do the "grease test". As the picture shows, there was something that wasn't quite right:
The seal had completely wiped clean the grease I had place on the retainer. I did this test three times with the same results. After thinking about it, I thought that the seal must not be seated all the way in the housing. After taking measurements I confirmed that it was 38.5mm from the outside edge of the housing to the outboard edge of the seal. This matched what I'd measured before removing the old ones (I did not confirm the seals where the same width though):
So, I slowly came to the conclusion that these particular seals required the retainer and ABS tone-ring to be pressed in further. I ended up going millimeter by millimeter until I arrived at what I thought was a good result from the "grease test". I ended up just a hair past 10mm of polished axle showing:
I think the seals that are included in Low Range Offroad's kit actually have a wider sealing surface with multiple ridges for sealing. I've not conferred with them yet to confirm that, and didn't think to take pictures before putting both seals into the axle housing. I've got this one of it already in place that seems to confirm my theory (you can see a ridge in the front, the middle and the rear of the seal):
Not sure if anyone else has used this kit before, but for $76 and the quality of parts, it was the best deal I could find out there. Ultimately, after having a day to think it over, I still believe leaving the retainer pressed in with 5mm of polished axle showing will still seal up well with this modified seal. It may even be possible to not have to flip the retainer as well. Only question remaining is whether the longevity of this seal is on par with Toyota's. Time will tell.
One question I do have is whether the OEM Toyota seal has only one sealing surface and whether it's on the inboard edge of the seal?