Author Topic: Servicing Shimano Dynamo hubs.  (Read 350 times)

Servicing Shimano Dynamo hubs.
« on: February 04, 2021, 05:54:05 pm »
Thought I’d leave this here. 

I’ve serviced my Shimano T785 Dynamo hub bearings. I can confirm it’s possible to service the RH bearings. The key is dismantling the electrical connector to release the wire. After that there is a groove in the axle which you can push the wire into whilst you remove the cone. After that there’s a seal , then you can access the bearings and cup.  The wire is more robust than others have made out, though if you are gentle it’s easy enough to access the hub without putting any undue stress on it.

When reassembling there is a circular piece of metal you insert into the electrical connector that engages with the connector body and groove in axle. This ensures the connector turns with the axle and protects from the wire getting pulled apart.

Screwing the cone back on with wire out the way in axle groove

Showing the groove in axle

The connector fits to , to ensure it rotate in line with axle. Plus push wire in there when removing / fitting cone.

The parts of the electrical connector

These easily prime apart with a brawdawl or similar. Photo shows left to right from locknut to seal after which you’ve reached the bearings and cup. The metal clip wires spring out / in to place. There is one part not shown in photo. The circular metal bit which fixes connector against axle. Didn’t realise it wasn’t in photo till after I’d finished,

Re assembled before tackling LH bearings

But anyway it’s not that hard to service RH as well as LH bearings and easy enough not to worry about the wire if you take your time.

Re: Servicing Shimano Dynamo hubs.
« Reply #1 on: February 04, 2021, 07:50:22 pm »
Useful information, thank you for sharing


Re: Servicing Shimano Dynamo hubs.
« Reply #2 on: February 15, 2021, 06:52:27 pm »
Thank you, this was very helpful. Mine has a nutted axle so it was a little more difficult as the cone could not be removed.

All in all though it worked out well so thanks. Took be about an hour to do both sides.

Re: Servicing Shimano Dynamo hubs.
« Reply #3 on: February 15, 2021, 09:21:53 pm »
Glad it was of use.  Means the Shimano hubs can be kept going a lot longer if you can service properly.