2006 Tundra 4WD - Transfer Case, Amsoil SVG 75W-90

[btanchors]

Here is the first UOA on the Transfer Case of my 2006 Toyota Tundra 4WD Limited Double-Cab. This is the first fill of Gear Lube after the Factory fill was drained and replaced. I suspect the wear is very high because the vehicle has been barely used in 4WD mode - just enough to occasionally exercise the 4WD drive train. Perhaps it will get more of a workout this winter. Also - Note how high the TAN is. I also had even higher TAN readings on the front differential and rear differential with the same service interval. I suspect, but do not know yet, that the initial TAN on a virgin sample of this gear lube must be in the 2-3 range. I am opening a separate topic to discuss TAN levels in the ATF, Differential, Trans, Brake, P/S forum. Meanwhile, here is the UOA:

 

[unDummy]

Wear is high. Silicon is high. Possible dirt ingestion while refilling xcase(and frontend). Run truck through undercarriage wash prior to changing fluids again.

Xcase still needs breaking in. Visc/flashpoin look perfect. Tan is high but 'consistent'. Xcase doesn't stress fluid as much as rearend.

I expect that the 'sealers' and 'sand casting' mostly left with the factory fill. Si could also be part of material formula. Once you gather some more UOAs, you'll know more.