I changed mine out last weekend, went with mobil 1 20-50 and followed the avove mentiond diretcions and every thing went very smooth.
Question, am I supposed to change the gear oil / transfer case oil too when changing to a full syn oil???
You don't have to change the transfer case oil unless it is time or you just want to. I elected to change my transfer case lube to synthetic when I changed my engine oil to synthetic, only because I wanted synthetic in my transfer case as well. The transfer case lube change interval is initially at 600 miles or 1 month then, check level at 8000 miles or 12 months then, change at 16000 miles or 24 months thereafter. Note: some people say they use engine oil in the transfer case however, I do not. The owners manual says to use SAE
80 GL4 Hypoid gear oil. I went with Amsoil Severe Gear 75W90 for my transfer case. It is rated for GL5 but Amsoil says it can also be used in applications requiring GL4 (backwards compatible).