I used a bolt threaded into the splined shaft and pulled. I had one that was real stubborn, so I had a helper run the engine, hold the brakes, and shift between D-N-R while I pulled. That worked wonderfully.
Transmissions, differentials, and other parts of vehicles have air inside them. The air can heat up and expand, or cool and shrink. These parts need vents to let air in and out, otherwise fluid would blow past seals, or other problems would...
Reviving an old thread again... Because it's crucial info. Here is a post-timing belt failure teardown of a 4.7 2UZ-FE, from a Tundra. Spoiler alert... Nothing bad happened inside. Interesting insight video.
Do you have a long socket extension or screwdriver? Something metal. Makeshift stethoscope. With the engine running, touch it to each fuel injector, other end to your ear, and see if one isn't ticking like the others.