95 T100 4wd. I have replaced the left rear axle seals, sleeve, and bearing twice due to oil leaking into the brake, with less than a year between repairs, and it has started leaking again. All the parts look good with no apparent cause for leakage. The truck has 140k miles, has seen minimal off-road use, has a Powertrax No-Slip automatic locker, and Amsoil in the diff. The second time I replaced parts I RTVed the sleeve that the seal rides on, thinking that perhaps oil was leaking between the axle shaft and the sleeve. I had the alignment checked a few months ago when I replaced tires, and it indicated that the axle has a slight bend. Anyone have any thoughts or advice?

 

I was thinking bent axle and then read it towards the end. Durr....

Get that axle replaced - if the seal(s) look good then they probably are. That is definitely a way to get oil past the seal (into the housing).

 

Check your diff. breather. If it is clogged pressure builds up that eventually busts your seals

 

The second time the leak developed, it occurred to me it might be the vent. The vent fitting was clear, as was the hole into the axle. I also considered at the time if the axle might be bent, but I couldn't see how that would cause a leak- the axle shaft splines are not a tight fit into the differential so will allow quite a bit of wiggle at the outer end, and hence no side loading of the bearing or seal. The tire seems to run true, so the axle shaft is probably not bent. If I replace the axle, any thoughts on whether a T100 junkyard or something like a Ford 9"?

 

Double check the axle, there was a TSB and Toyota now has larger bearings and seals and larger axle for the T100. Went through this myself until I found a good parts guy to help me out.