This is UOA number 2 on the Front Differential of my 2006 Toyota Tundra Double Cab 4WD. I am not sure what is causing the high silicon, I thought I was pretty careful not to contaminate the sample. I used an unused plastic tube and a sampling pump to take the sample. I tried to keep the end of the tube at roughly the "middle" of the level of the fluid, so I wouldn't pull anything from the bottom of the compartment...Also, the sample was taken when the fluid was warm. The virgin, unused TAN level tested out at 4.3 on this oil. Comments?
