So I replaced my inner seals and bearings today. It was a long process doing it all myself, but in the end I'm glad I bought the press and all the tools to do it. Saved myself a ton of money and now have some nice tools for future projects.
I just recently bought this T4R from a guy here who replaced the seals and bearings (so he told me) not long ago. The maintenance records show them being done at 136,000 miles. At approximately 139,500 miles I noticed the driver's side leaking badly and just barely some signs on the passenger side. During that week I noticed a significant change in the braking performance so I am confident that it all started very close to that mileage.
I thought all this strange since the PO had recently done the work, but as ya'll saw in my previous posts in this thread I checked the ABS ring and it was soaked on both sides. So I ordered parts and tools, and this weekend I got around to it.
While pulling things apart, this is what I found.
This was on both sides. I think these aftermarket seals are the culprit. I did drive the 4runner all the way from North Carolina to Texas when I bought it, and I thought about the diff breather, so I checked it and it was clear (breather mod previously performed by PO). So I dont think it was thermal expansion that did it. This is just more confirmation that the aftermarket Timken seals aren't worth it. Approx 3500 miles and they failed. Go OEM Toyota parts.
As a side note another thing I found was that he had replaced the driver's side bearing but not the passenger side, as evidenced by the original cream colored bearing seals, as opposed to the red that you get from Toyota today. I know they are expensive, but if you thought the seal needed replacing the bearing should also be replaced, just in case. But let me tell you - getting the last retainer and the bearing off without a custom press fixture basically leaves you with droping the axle onto the garage floor as pretty much your only option to get them off.