Old hub has started slipping. Need suggestions for servicing.

[beagley]

I did not look at your video, but I might have an idea what the problem is.

THis link that Ph previously posted has a graphic:
https://www.rohloff.de/de/erleben/technik-im-detail/explosion

Part number 41 is a pawl that is attached to the axle, there are four of them.

This youtube video:
https://www.youtube.com/watch?v=s4UpwoDmOb4

At time 4:36 it shows one of those four pawls on the axle in red in first gear.

At time 7:13 it shows two pawls in red in 3rd gear, one of which is the same as in gear 1.

I think you said those gears, plus 8 and 10 are the gears not behaving properly.

Perhaps that red pawl is not engaging for some reason?

That is my best guess.

Your description of rotating the wheel is what gave me this idea, perhaps gravity is helping that pawl engage when the wheel is rotated just right?  But rotate the wheel again, the pawl is not getting help from gravity?

But of course the bad news is that this is internal, so some significant labor time could be involved, even if the only fault is a pawl or pawl spring.

Thanks mickeg. That exploded diagram and the video helped me appreciate that (i) the axle ring is ganged to the axle and (ii) there are moving components attached directly to that axle, namely the pawls. Your hypothesis (one of the pawls not engaging) makes complete sense although it doesn't explain why the problem became markedly worse after replacing the inner gear cable. Maybe I just disturbed something.

There is the tiny chance that some grit is stuck somewhere that causes that pawl to hang up, in which case maybe trying to ride some in all gears with lots of shifting through all the gears, with only cleaning oil inside could cause some grit break loose and get out of there?  When was the last oil change?

Last oil change was only a few months ago. The problem had already appeared and the oil change didn't seem to help. However, I like your idea of "trying to ride some in all gears with lots of shifting through all the gears, with only cleaning oil inside" so will give that a go as a final straw to clutch at before contacting the shop in Bridgewater (thanks, PH, for the servicing suggestions).

Beagley

[JohnR]

Last oil change was only a few months ago. The problem had already appeared and the oil change didn't seem to help.

A few months ago would be mid-winter when the oil is more viscous is both less likely to flush any accumulated muck and also more reluctant to drain out. I support the suggestion to replace the current oil in the hub with flushing oil and clock up some miles with plenty of gear shifting. Then drain the oil before any bigger muck in suspension has time to settle. Depending on how that oil looks, a second flush might be beneficial.

At the moment I do my oil changes in spring and autumn as the miles need more than one change per year and I want to avoid doing this in cold weather for the reason noted above.

[JohnR]

Another thought: Is it possible to remove the shift mechanism and seal and squirt some GT85 or similar spray lubricant along the axle?

[beagley]

Another thought: Is it possible to remove the shift mechanism and seal and squirt some GT85 or similar spray lubricant along the axle?

Do you think it might be possible to access the axle (including the part where the pawls are attached) without doing a full disassembly? I'll watch one of those scary disassembly videos and give that some thought before possibly having a go. I guess I should be ready to replace the hub cap paper gasket while I'm at it.

[beagley]

These two videos from climbercraig66 on YouTube look very useful for anyone contemplating hub disassembly:

• Disassembly: https://www.youtube.com/watch?v=lS6kj8g5On8
  
• Reassembly: https://www.youtube.com/watch?v=Y-1iPbYra58

It's clear that a significant amount of disassembly is needed in order to get to the pawls mounted on the axle. Most of it looks straightforward but at 5:50 in the reassembly video climbercraig66 explains that the top sun gear requires a particular timing w.r.t. the planets it mates with and he glosses-over how to do this. Apparently, the planets have timing marks that must be aligned in order to properly mate with the last sun gear, but the marks can't be made out in the video. If I could find more directions to do that then I think I might have a go.
UPDATE: climbercraig66 provides clarification in posts #17 and #18 here: https://www.mtbr.com/threads/rohloff-strip-to-axle-and-rebuild-videos-english.659526/
UPDATE2: It seems climbercraig66 is Beave on this forum (Hi Beave, if you're still around!) and shared his videos on this forum back in 2010: http://thorncyclesforum.co.uk/index.php?topic=2829.0

BTW, I did an oil change this morning (with a 20 min ride and plenty of gear changing with the cleaning oil). No change.

[Danneaux]

Apparently, the planets have timing marks that must be aligned...

Yes, small and hard to see unless you have good lighting.

You may wish to read/review the Rohloff disassembly account posted by Matthew Signorini, son of longtime Thorn Forum member, Pete...
https://matt.signorini.id.au/?p=198
...it mentions the matter of timing marks as well with some cogent insights that may save you time and frustration.

Best, Dan.

[beagley]

You may wish to read/review the Rohloff disassembly account posted by Matthew Signorini, son of longtime Thorn Forum member, Pete...
https://matt.signorini.id.au/?p=198
...it mentions the matter of timing marks as well with some cogent insights that may save you time and frustration.

Thanks, Dan. A valuable read and has that useful tip on (at least trying to) avoid the need for aligning the timing marks during reassembly. Though I wouldn't bank on it not all falling apart if I tried it...

[mickeg]

I am an engineer (retired) and I have no desire to take mine apart if someone nearby can fix it.  Maybe if I was a Mechanical Engineer with the right experience?  But that is not my specialty. 

If you really want to try it, good luck.  I rebuilt the gearbox in my 1968 Triumph T100R a couple times over the 12 years I drove it, but that was a four speed that was a lot simpler.  I am not even tempted to try rebuilding my Rohloff.

I watched your videos on disassembly and reassembly, but they did not cover what is going on inside the axle shifting mechanism and how those pawls work.  They left that assembled.

This might help.
https://www.rohloff.de/en/experience/technology-in-detail/gear-steps-1-14

The 59 second video (first video) shows how the shifter works by rotating the inner rod with flats to control the four pawls on the axle and the two pins that move different parts in and out. 

But that still does not tell you how to disassemble or re-assemble the axle and shifting pawls.  Without knowing how to do that, good luck.  And even if a pawl was too worn to continue to function properly, you might not be able to recognize that.

And, if it is an obvious fault, can you buy the correct replacement part?  Will someone sell it to you?  That might be the deal killer right there.

I still think it is one of those pawls that is the problem.  But I could certainly be wrong on that too.  There is no certainty that my diagnosis is correct.

The videos did not say what gear it was in when they started to disassemble it.  I am guessing you should start in gear 11.  I suspect other gears could have

[mickeg]

Ahhh, one more video.
https://www.youtube.com/watch?v=pHiBcXukmOM

At about 2:34 he starts describing (in German) the shifting mechanism.

And at about 4:29 he turns the shifter with a wrench and ... you have to watch it.

I started laughing as the parts went flying.

[JohnR]

I think you've explored the easy possible fixes and it's time to pass the wheel to the experts (SJS Cycles) who should not only fix that problem but also replace any other parts that are getting worn. You'll then have a hub that should be good for many more years of happy pedalling.

[Ph.]

I had a problem with my 2007 Rolhoff hub back in 2016 where some gears were only engaging in one direction & the hub would slip in neutral instead. I phoned SJS about this problem and after a grilling about my service history they said I could send them the wheel & that they would send the hub innards to Germany for investigation. I was worried this might become an expensive bill, so was very pleasantly surprised when less than 2 weeks later my wheel arrived back with a note from Rohloff apologising that I had had a problem, which had been fixed by re-shimming the mechanism. 

Ph.

[PH]

If you go down the disassembly route please document it, I'm as curious as anyone!  I think other than satisfying the curiosity, there's only a slim chance you'll cure it, the likelihood to me seems to be a broken part and Rohloff don't supply.  If it were mine I might be tempted to pull the innards out, just to see if something was obviously broke, dislodged or jammed, that's a simple step, I've done it once when the hub had been submerged, but that's as far as I'm ever likely to go. If that's done, the gasket should be replaced, but as it's likely to still need sending away, I wouldn't bother.
Good luck

[beagley]

I think you've explored the easy possible fixes and it's time to pass the wheel to the experts (SJS Cycles) who should not only fix that problem but also replace any other parts that are getting worn. You'll then have a hub that should be good for many more years of happy pedalling.

Yeah, having slept on it I've decided not to chance it. What helped make my mind up was reading some of the comments under that Matthew Signorini post that Dan shared; some folk had got themselves into a right pickle.

I spoke to SJS yesterday and they have offered to take a look. Hopefully they can get it sorted while I'm away on a six week tour (of Germany, coincidentally) on my other Rohloff equipped bike. If all goes to plan I'll reply again at the end of June to let you know how it went.

Cheers,
Beag

[beagley]

I spoke to SJS yesterday and they have offered to take a look. Hopefully they can get it sorted while I'm away on a six week tour (of Germany, coincidentally) on my other Rohloff equipped bike. If all goes to plan I'll reply again at the end of June to let you know how it went.

After an initial inspection SJS corresponded with Rohloff who suggested to replace the hub internals with a new set. Rohloff covered the cost of this since I am the original purchaser and the hub was registered with them. Frankly, I'm staggered. So effectively I now have a new hub 

While doing the work SJS replaced the non drive side bearing (and seal) as well as the bearing seat on that side. There was a build up of grime within the seal and the bearing was slightly rough, so they decided it was sensible to replace that while they were in there. I was charged for this. I'm very happy they took the initiative.

Interestingly, the old internal will go back to Rohloff and the parts will be stripped and reconditioned. Rohloff offer re-con hub internals for hubs over 10 years old in Germany; they may well roll this service out worldwide in the future.

Beag

[mickeg]

...
After an initial inspection SJS corresponded with Rohloff who suggested to replace the hub internals with a new set. Rohloff covered the cost of this since I am the original purchaser and the hub was registered with them. Frankly, I'm staggered. So effectively I now have a new hub  ...

Mine is nine years old, almost broken in now.

Thanks for the update.