Read through this extensive first post. The post is over 10 years old but very informative. It is the initial source of my information about the TJ/JK suspension and probably appropriate to the JL as well (except for maybe the bolt and hole sizes).
There are links to three You Tube videos (2 at the start and 1 at the very end (link text very small). You will note the first post has the tag that it was modified by a moderator. They modified the size of the text font after forum conversion to new host shrank the text to a tiny font which was hard to read.
Many things that are wobble/shimmy related are tagged with the DW labeling on some posts but are not. You apparently got to see first hand a death wobble on another Jeep.
The previous four post all have excellent points, I thought this linked thread would help you. It is lengthy because of the long videos, but they are not boring.
The videos are kind of long at 18-19 minutes each. Hopefully, they are thorough enough to help. Death Wobble Diagnosis and Inspection Jeep JK Wrangler Part 1 - YouTube Death Wobble Diagnosis and Inspection Jeep JK Wrangler Part 2 - YouTube Inspection Checklist is in Post #2. I'll start out by...
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