Ideally, you want to fit six frictions inside the direct clutch apply drum on the TH400. To achieve this, a transmission builder must select the thinnest combination of steel discs and friction elements. The more you fit, the longer the life span of the clutch material will be. However, if you install too many clutch packs, you will not have enough endplay and this can cause a harsh reverse engagement. Ideally, you want 0.004 to 0.006 inch of endplay in the direct clutch pack.
