[Gear hub] Shimano alignment tool TL-8S30
 

Hello,

Out of curiosity, what is the Shimano alignment tool TL-8S30 for?

Is it required to put a Nexus/Alfine gear hub back together, or just nice to have?

Thank you.
https://cimg7.ibsrv.net/gimg/bikefor...b98fc1c120.png

the purpose of that tool is to phase the planetary gears. The Nexus/Alfine gear carrier sub assembly has the sun and planetary gears in constant mesh, so unless you disassemble the gear carrier that tool is not necessary.

even if you do take it apart to that extent it is possible to phase the gears without the tool. This video explains the concept behind it although it is a totally different hub.

This ^^
You can open the hub and oil-dip or re-grease the gear cluster without disassembling the gear carriers themselves. I've been doing this for years with Nexus 7 and 8 speed hubs, and have never found it necessary to take the gear carriers apart.

Thank you.

So it's only needed (convenient, rather) if you take a hub completely apart for a thorough cleaning + lubricating.

You can go as far as removing the gear carrier from the axle without having to worry about phasing the planetaries.
Once you disassemble the carrier it becomes necessary

Whatever you do, don't take apart the "Axle Unit" (the long skinny part the gear carrier modules ride on)!
I did this once on a Nexus-7 and never got it back together. I've been meaning to swallow my pride and send it to Rat City Bikes (lots of interesting pictures on this link).

It can be done. I have never done a video showing the removal and replacement of the actuating arms and pawls, but I did do one showing how to get the shift spring assembly back together.

Thanks, Dan!
I know it's possible, and I've seen some other videos and pictorials about it but haven't had the need to do it... I have several other Nexus hubs. I should probably review your video and the others, then give it the old "amateur mechanic's" try!

EDIT: I just watched this video. Your understanding of the mechanism and ability to reassemble it is nothing less than awesome! But I'm wondering how in heck this thing was designed in the first place! I will have to dig out the box I put the parts in and see if I can follow your guidance. Thanks again!