I had to replace the front seal with the transmission still in the car. Pulled the engine up far enough to get the torque converter off then removed the old seal. Driving the new seal in with the output shaft in place was hard but fashioned a seal driver out of a 3" to 1.5" pvc reducer with a 4" long piece of 3" PVC gave me room to clear the output shaft and the 1.5" side gave good area for the hammer face to pound on. The 3" PVC was the perfect size for the seal without distorting it.