GM Shift Selector Shaft Seal Installer and Remover Tool with Seal (TH350, TH400, 700-R4)

The manual shift selector shaft is the shaft the shift linkage bolts to where it enters the side of the case, and the little seal riding on it is one of the most common slow leaks on an older GM automatic. You will see it as a wet spot high on the case that everyone blames on the pan gasket. Replacing that seal by hand is a fight: it sits in a shallow bore with almost no room to grab it, and if you pry at it with a screwdriver you gouge the case or nick the shaft and it leaks worse than before. This little kit is the right way to do it.

It works in two steps. The extractor threads into the old seal so you can draw it straight out instead of prying against the aluminum, and the driver seats the fresh seal dead square to the correct depth so it does not cock and start weeping again. Because the tool comes at the seal from outside the case, in most cases you never have to drop the pan or lower the transmission to get the job done. A new seal is included in the kit so you can finish the repair in one shot.

Coverage runs across the common GM automatics: TH350 and 350C, TH400, the Turbo 200, 200C and 200-4R, the 425 and 475, and the 700-R4 and 4L60. One note straight from the guys who use these: give the extractor a light tap with a hammer to set it, then run it a turn and a half into the old seal before you pull so it gets a solid bite. Note the 700-R4 and 4L60E use a longer selector shaft, so on those you drive the new seal with a socket rather than the included driver. Ships from the USA.