yeah, ive seen VOA's on the toyota fluid. can you explain what these magical additives are that other quality synthetics or conventional gear oils dont have? & why mobil gear oil has "no additives to protect the T/case?" thats pure non sense! mobil or amsoil etc are not "cheap" in any way & not one single user of mobil or other non toyota gear lubes have ever had any kind of problems protecting the t-case.

why are you telling us we "have" to use toyota fluid in the xfer case when toyota themselves say in the owners manual to simply use a gear oil that meets the right weight & rating? i have never seen anything about absolutely needing to use toyota branded gear lube lubes in any pre 2015 4runners or tacomas. there is some info that says for 2014/2015 & later toyota uses that special gear lube, but that does NOT apply to any earlier year 4runner, tacoma or FJ etc, & even the dealerships just use a common bulk 75/90 GL-5 lube on these years. if you are only referring to 5th gens then that may be the case, but there are countless 5th gen owners using mobil or other synthetic lube with zero issues.

& i have no problems using the "wrong lubricants"... so not sure what thats supposed to mean... my 2008 T-case works excellent & is smooth & quiet using valvoline 75/90 synthetic. but then again you think you can tell by looking at the plug threads that the toyota engineers were off by 4 ft lbs on their torque ratings! LOL!