Some kind soul has created a download of Shimano service docs! It looks like the contents of Shimano's old Australian site that is now gone. Here is the description:
Go here to get the torrent file.A collection of Shimano technical documents, focusing on older road bike components that are still in widespread use, but for which Shimano no longer provides documentation. Includes DA 7700, Ultegra 6500, 105 5500, etc. Some MTB. PDF format. ENGLISH.