a bodies and 4 speeds

hi, have a 833 in my A body, its 18 spline, that rare? anyway ive fitted a hurst shifter,re done all connections however think maybe trouble in box itself, drives great in all 4 gears, smooth, no whines etc, just dont think each selector fork sitting happy in each neutral,goes into 1st,2nd somtimes awkard, 3 - 4 great. anyone have a schematic:read2: of box with casing off please? many thanks, happy new year all.its called detent system that needs to be looked at....