The lower ball joints didn't have grease zirks but they had a boss where one might go. Me not trusting they put enough grease in and I like to service my stuff, I decided to add one.
Here I milled the boss flat.
Next I used a center drill to keep my actual drill from waking.
Here I drilled the hole with a #3 drill. I used my shop vac to reduce the amount of metal shavings going inside. I also used a feed rate that kept the chips as a string (or as we call the at the shop "danger noodles").
Then I hand tapped the hole 1/4-28, no power tapping today, I didn't want to run into the ball and snap my tap.
Next I chamfered the hole. I have chamfer tools but these step bits work great for this.
Thead in the zirk and clock it correctly and then add grease.
I always find this type of work interesting and thought I'd share.