Sorry for postponing of my report.
I've spent some time to learn the particular internal gear hub. It is complex peace of machinery. Lubrication requirements seems to be at the low end side, but they are quite contradicts.
- Ball bearing range DN numbers - D=20mm to D=92mm N=0...400tr/sec.
- in some ball bearing the grease is used to seal from outside water.
- roll bearing requires lowest possible NLGI grease since they are responsible for gear switch.
- needle bearing d=1mm needle located inside of planetary gear. Note cage is plastic
- planetary sun and ring gear
I've read shimano tech articles, bikes forms and look for possible problems in this IGH.
I prepared my own mix of NLGI 0 grease - Mobilith SHC 100 + mobilibe 75w100
After research and preparation phase i take some actions.
- disassemble my Shimano 8 speed premium hub. according to shimano reference guide. Some additional literature helped me too.
- degrease all parts.
- apply pure mobilith shc100 NLGI 2 grease to all ball bearings and gears. Sealing is essential.
- Use my own made NLGI 1 grease for needle bearing. I heat up the grease with hot air gun to T=100 C. keep in mind that cages are from plastic. On such way the grease penetrated to small needles.
- Apply some NLGI 0 grease for the rest. E.g. pawls, roller clutches carriers etc.
I did reassemble the hub and it runs without any issues. I did first 100km and the initial drag disappear. The gears are switched easier.
The hub is ready for next 12 months/5000km.
1. The lubrication of IGH is a big tradeoff between different parts. Some parts requires low viscosity base oil another high. Some area requires NLGI.2 another can use pure oil.
2. Good analyze an d theoretical background are more important that using a very expensive but not suitable lubricant.