17. 4L80E / TH400 intermediate sprag and drum. The 34 element sprag has over twice the holding power of the stock sprag. Eliminates intermediate sprag failure due to excessive torque input. The TH400 34 element PATC sprag replaces the stock 16 element unit, increasing the torque capacity by 110%. Standard in all PATC TH400 race transmissions. A mandatory addition to any TH400 used in racing or heavy duty applications. (for both).