I've been using Amsoil's synthetic oil, gear oil, and transfercase fluid too for 30,000 with no issues.
I'll use their transmission fluid too when the time comes.
It is expensive, but I think it is ultra high quality. (Not a distributor.)
MOLON LABE: 2006 WK Limited, Dark Khaki Pearl, 5.7 HEMI, QDII,
Console XDs-45acp, Billet Catch Can, Airaid CAI Tube,
1" Spacers, Steel Armadillo Sliders, Dark Khaki 4xGuard Front Skid,
Dark Khaki 2011 #9104 Wheels, Firestone Destination A/T 265/70/17's.
OME HD lift. Dark Khaki Matrix Brush Guard, Dark Khaki Painted Headlight Bezels.
Hemi Club #65 // Khaki WK Club #40