Sonnax 34034T-01. TH350 / TH400 Teflon Pump Bushing. Worn babbit pump bushings in TH350, TH400, Powerglide and Allison AT540 units allow the converter hub and inner pump gear to move off-center, causing damage to the pump gears and pump housing crescent. Sonnax pump bushing 34034T-01 is a direct replacement part that is better fitting than OE. Extremely wear resistant, this Teflon lined Kryptonite bushing helps maximize the life of these older and increasingly rare pumps.