pilot bearing
here is a link to some pics of a clutch change that might help you to go through
https://forum.ih8mud.com/40-55-series-tech/245021-pics-oem-p-ns-rear-main-clutch-change.html
pic 1 here is the bearing from Toyota for my 2f/4spd
pic 2 here is the shaft that goes into the bearing--I am just pre-fitting it here
pic 3 here is where the bearing is installed before you put the transmission in---the shaft sticks out the front of the tranny and goes into the bearing as you push the tranny forward to mate up to the bell housing
I used a loaner bearing puller free of charge from autozone---it was the slide hammer type and both jaws were too big to go in so I just used one jaw and angled it to the side a little and gave it a whack---it came right out
A couple of important things---First , the clutch only goes in one way--make sure you know---it is easy to tell so post up if you are not sure and we can find a pic to help
second, You must prefit the bearing on the shaft---it is close tolerance and any nick or manufacturing spec a little off and you will not get yur tranny to slide in. Slide the bearing on the shaft and it should slide on easily. If not clean up the shaft with emery cloth until it does---bout 10 minutes work for me
Finally, make sure the throw out bearing (attaches to the clutch fork) is installed the right way round when you do it, it only goes one way, some are obvious some not
hope that helps