I have a 2.5 gallon jug with about 2 gallons of Amsoil Multi Vehicle ATF that is about 20-23 years old I believe, it has the ATF+4 rating that my jeep needs for Trans, PS, transfer case. It has been stored in the garage in So. California tightly capped. I wouldn't use it for the trans (5 speed auto) on my 17 Wrangler, but do you think it would be OK in the PS and xfer case?