Shimano Nexus gear hub service/overhaul

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A step-by-step tutorial on how to service Shimano Nexus gear hubs without any special tools or lubricants:


Relja
 
An Alfine 8-speed is shown, not mentioned in the video I think.

Please also consider these important points:

1. After cleaning with solvent, let it dry for a day so there is no more solvent left deep inside the gears, else it will thin the new oil.

2. The whole internal assembly must be submerged in oil as directed by Shimano. I believe this is necessary so oil can penetrate deep inside the geartrain. Particularly important are the planet gear pins (axles) and needle bearings, which see a lot of pressure and wear. Oil may not get into these bearings by applying oil from a can or eye dropper.

3. After submerging in oil, I believe the reason Shimano says let drain for only 90 seconds is, they want some oil left inside so it can drain into the hub shell once everything is put back together. This forms a small oil bath that the gears can run through and get continuous lubrication, much like a crankshaft dips into the oil sump of a car engine as it rotates.

4. No lubrication is necessary on the external gear selector ("cassette joint" in Shimano speak). This will only attract dirt and get in the way of the shift cable winding around the pulley, possibly making shifts inaccurate. There are actually no parts sliding against each other in the cassette joint ... the 2 sections of the cassette joint are fixed to the axle assembly with separate splines, and bearing takes place on the axle assembly. Study how the cassette joint mates with the axle assembly to understand this.

5. There is no reason to check if the planet gears are synced because you haven't taken the geartrain apart. (Doesn't hurt to check.)

6. I like to take the hub apart down to individual components to get them really clean. I think that makes it last longer. But don't take the axle assembly apart, that's a real pain to put back together with the springs (even though there are videos showing how).
 
An Alfine 8-speed is shown, not mentioned in the video I think.

Please also consider these important points:

1. After cleaning with solvent, let it dry for a day so there is no more solvent left deep inside the gears, else it will thin the new oil.

2. The whole internal assembly must be submerged in oil as directed by Shimano. I believe this is necessary so oil can penetrate deep inside the geartrain. Particularly important are the planet gear pins (axles) and needle bearings, which see a lot of pressure and wear. Oil may not get into these bearings by applying oil from a can or eye dropper.

3. After submerging in oil, I believe the reason Shimano says let drain for only 90 seconds is, they want some oil left inside so it can drain into the hub shell once everything is put back together. This forms a small oil bath that the gears can run through and get continuous lubrication, much like a crankshaft dips into the oil sump of a car engine as it rotates.

4. No lubrication is necessary on the external gear selector ("cassette joint" in Shimano speak). This will only attract dirt and get in the way of the shift cable winding around the pulley, possibly making shifts inaccurate. There are actually no parts sliding against each other in the cassette joint ... the 2 sections of the cassette joint are fixed to the axle assembly with separate splines, and bearing takes place on the axle assembly. Study how the cassette joint mates with the axle assembly to understand this.

5. There is no reason to check if the planet gears are synced because you haven't taken the geartrain apart. (Doesn't hurt to check.)

6. I like to take the hub apart down to individual components to get them really clean. I think that makes it last longer. But don't take the axle assembly apart, that's a real pain to put back together with the springs (even though there are videos showing how).

Yup - edited the title. Thanks.
The new 11-speed Alfine has an oiling port, a lot like Rohloff (in terms of procedure), while the 8-speed Alfine is a lot like Nexus 7 and 8-speed.

There is the Shimano's recommended procedure (with their internal gear hub grease), and several "alternative" options. The procedure shown is what's worked well for Mićko - he loves and rides geared hubs a lot. Quick, simple, and using cheap automotive lubricants.

Relja
 

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