[cas3]

here's the tools i made for doing it. not shown is a hunk of 1" thick steel with a hole thru it. thats for using a good two jaw puller to get it off, and the base to press on when installing. i made a small bit on the lathe the size of the shaft with a slot milled in the the key on the worm to clear when pulling it off, and the aluminum block grabs the shaft for pressing the new one on. i have done a few, and found that when just replacing them, it goes well, no heat needed. however, when doing one that i had shortened a shaft, so the worm was going on to virgin territory, it got tight, and a slight warming with a propane torch got the job done. if you measure the shaft woth the worm off, you will find its about 5 thou smaller from ford pressing the gear on that tight.