 For the suspension of any car to operate as it should, for proper handling, and to keep the body panels in alignment, the frame has to be strong enough to cope with the loads applied to it.It must not deflect, and it has to have enough torsional strength to resist twisting.A "K" member is a crossmember in a vehicle with a longitudinally-mounted engine, contains the engine mounts.cross member of frame is I section.