Hey Stone 4x4, I've got about 5 inches of suspension lift and no body lift. The oil fumes tend to come and go either when I 'm in traffic, on the freeway at speed or on the trail. You may be right in the sense that the exhaust is heating up the t-case and the only place where the t-case can breathe is through the shift boot and hence into the cab. I'll look into fabricating some sort of heat shield. Have you had a similar probllem?