Originally Posted By: MacGyver
Lube guard is a well respected additive, that has been used in the automatic trans rebuilding industry for many years. When added to a new rebuild or even to a good seasoned tranny it will improve and stabilize the fluid against thermal breakdown. In some cases it will improve shift quality and stop torque converter lock up shutter. It has a friction modifier package to reduce friction and heat. It’s been endorsed by OEM's for many years. It will not "fix" a problem. As the others said - not a Mechanic in a can.
+1 It is not a cure all but does help with heat, as well as TC shudder, and works as advertised. I've used it, and know transmission shops that recommend it.