i have a 85 k5 blazer ,rebuilt transfer case and it kicks it's self out of 4hi after a block or so 4lo is fine . if i hold it in 4hi it stayes in gear fine and know bad sounds coming from transfercase. i think i have a np208...all i can tell it look like the shifter linkage has a retaining spring and it layes against the shifter arm pushing it toward the left side . witch looks like out of 4hi into 2 hi ????(i think?)checked the chilton books but no diagrams??? and ideas????? p.s what's it usaly cost to repair a gas tank and install ?