https://forum.ih8mud.com/100-series-cruisers/401590-official-clunk-thunk-driveshaft-thread.html
this thread is huge.
My summary -- put grease in the points shown on schematic until it oozes out like the picture I attached. This pushes all old grease (designed to trap sand, water, etc.) out and ensures you have all new grease.
page 2 of this thread fires up the argument you shouldn't "overfill" and when to do it. Essentially you can't overfill IMHO as the gunk will come out not rupture a seal or lock up the shaft as some suggest.
What is clear is that it should be done ATLEAST at every oil change. since 100% of soccer mom's know squat and most stealerships (see thread) DON'T grease zerks per Mr. T. I feel missing it once or twice is no biggie.
Regular greasing will help keep it lubbed and help with THE THUD (per thread). I think at oil changes is plenty unless you live in a very dusty environment or do lots of water crossings.
Having discussed frequency you are welcome to use my gun but you may be better off hitting a parts store for a $15-$25 gun to keep in the garage. Thread also discusses type of grease. There are hundreds of types of Molly grease and you can read the thread for what you want to use.
probably way more info. than you wanted but I assume some other new to 100 guys like Andy and others may benefit from my boredom.
I can bring my gun to the meeting this week....let me know
--edit-- picture is front drive shaft and in upper right corner you can see the grease line hooked onto the slide yoke and just a little grease coming out. Guns and spider, yokes (zerks) are universal so you should be able to push firmly and have it fit over the zerk. (a rag and wire brush may be needed if you truck is a dirty girl)
edit to the edit --- just finished. I could hear a crackling sound as grease oozed into sight from shaft. zerk's nipples (insertjokes) are actually ball point valves and when you clean if off you can see it. I got to all 6 at once, which is rare I think, except for having to remove my plastic skid plate to get to the front 3 (left in pic)
