Shimano Alfine 8 - sealing & servicing

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amacyc
Posts: 3
Joined: 23 Mar 2019, 12:29pm

Shimano Alfine 8 - sealing & servicing

Postby amacyc » 23 Mar 2019, 12:40pm

Hey guys, my previous bike had an alfine 8 which I never maintained. It was fine for 1,5-2years, but after the second winter it suddenly developed a rumble from the IGH when coasting. Opened it up and it had corroded, probably because of water ingress. Unfortunately I didn't take any pictures of it. I applied Shimano grease to it but it didn't help much - I'm thinking the internals need to be replaced although it's expensive.

Anyway, I'm about to buy a new bike with an Alfine 8 IGH, but am wondering what's the best way of preventing water ingress on it, and when to do it. Should I immediately open it and apply generous amounts of official Shimano grease? Ride it for a few months and then open it? I've read people suggest using oil, but I'm thinking that won't prevent water ingress, and I really want to avoid oil leakage.

So any help would be much appreciated! I really want to prevent water ingress on it to make it last as long as possible, having to replace the IGH ever 1-2 years is not acceptable.
Last edited by amacyc on 23 Mar 2019, 4:11pm, edited 1 time in total.

grufty
Posts: 19
Joined: 26 Sep 2017, 2:24pm

Re: Shimano Alfine 8 - sealing & servicing

Postby grufty » 23 Mar 2019, 2:18pm

We've been using Alfine 8s for 10 years now, so I can relate to your issue. Once the initial horror on opening the hub passed, I found that dunking the internals in automatic transmission fluid and applying liberal amounts of (waterproof)grease to the bearings, especially the drive side, works well enough for us. Mrs Grufty and I have 2 Alfine 8 hub bikes each, the 2 oldest hubs being 10 years old, we fnd that her hubs are in better condition for some reason. There is a small amount of drippage initially, but leaning the bike towards the non drive side helps.
There have been several threads on this or similar topics, hopefully Brucey will comment shortly as I seem to recall he suggests using a different viscosity oil. I would be interested to hear his opinion!

amacyc
Posts: 3
Joined: 23 Mar 2019, 12:29pm

Re: Shimano Alfine 8 - sealing & servicing

Postby amacyc » 23 Mar 2019, 4:10pm

grufty wrote:We've been using Alfine 8s for 10 years now, so I can relate to your issue. Once the initial horror on opening the hub passed, I found that dunking the internals in automatic transmission fluid and applying liberal amounts of (waterproof)grease to the bearings, especially the drive side, works well enough for us. Mrs Grufty and I have 2 Alfine 8 hub bikes each, the 2 oldest hubs being 10 years old, we fnd that her hubs are in better condition for some reason. There is a small amount of drippage initially, but leaning the bike towards the non drive side helps.
There have been several threads on this or similar topics, hopefully Brucey will comment shortly as I seem to recall he suggests using a different viscosity oil. I would be interested to hear his opinion!


Thanks a lot for the reply. What about just using lots of waterproof grease and no oil? My main concern is just making the hub last. By the way, what grease do you use? I've used the official white shimano grease but am concerned it's not waterproof enough to prevent ingress of water.

Also, do you think perhaps dunking the internals of my corroded hub in ATF will be able to fix it, or is it a lost cause?

I've read a few threads on the issue(s) and it honestly seems like a bit of a mess. Shimano makes these hubs which are not sealed sufficiently and thus will inevitably allow water ingress if driven in winter. The hubs are greased from the factory, but in the service manual Shimano recommends using oil. If you then use oil it leaks and contaminates your disc brakes. Furthermore oil alone is not enough to prevent water ingress. So now we're in a situation where some people use oil, some use grease and some use both. I just wish there was a comprehensive guide to properly maintaining the different hubs - nexus 7,8 and Alfine 8, 11.

Brucey
Posts: 35987
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Brucey » 23 Mar 2019, 4:24pm

once an 8s hub becomes rumbly (in gears other than gear 5 and when freewheeling) it usually means the large 'ring bearing' is damaged. If the damage isn't severe the hub will carry on working but no amount of maintenance or lubrication alone will fix the rumbling; that is caused by damaged bearing surfaces on parts that can't (sensibly or at all) be renewed any cheaper than a new hub.

The LH bearing has lip seals on it and you need those seals to have failed completely, the bike to be laid on its left side and/or the hub to have a ridiculous amount of oil inside before it will leak out on the disc.


Use grease in the end bearings by all means but you are better off with oil or semi fluid grease (SFG) inside the rest of the hub because it will keep the seal lips wetted properly, whereas grease won't, not indefinitely. When the seal lips are not wetted with lubricant, they first leak water into the hub and then the seal lips swiftly wear so that the seals may as well not be there.


Hubs like this need maintenance; it is "not acceptable" to expect them to carry on working without such maintenance. You can very reasonably expect them to fail in UK weather if they are not maintained correctly.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

amacyc
Posts: 3
Joined: 23 Mar 2019, 12:29pm

Re: Shimano Alfine 8 - sealing & servicing

Postby amacyc » 23 Mar 2019, 4:50pm

Thanks for the reply. Do you recommend immediately oiling and greasing a new hub, or riding it for a year or so before doing first maintenance? And how often should you maintain it if you're riding the bike year long - once a year? Also, would using the official shimano oil and grease be "good enough" to prevent water ingress?

My comment about the hub not being acceptable simply refers to it being an expensive part and as such having to replace it every 1-2 years would not appropriate. I have no problem having to maintain my bike, but honestly these hubs are very often sold as being no or minimal maintenance which imo is not the case.

Brucey
Posts: 35987
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Brucey » 23 Mar 2019, 9:10pm

amacyc wrote:Thanks for the reply. Do you recommend immediately oiling and greasing a new hub, or riding it for a year or so before doing first maintenance? And how often should you maintain it if you're riding the bike year long - once a year? Also, would using the official shimano oil and grease be "good enough" to prevent water ingress?

My comment about the hub not being acceptable simply refers to it being an expensive part and as such having to replace it every 1-2 years would not appropriate. I have no problem having to maintain my bike, but honestly these hubs are very often sold as being no or minimal maintenance which imo is not the case.


If you use lubes that are not shimano-approved there is a theoretical chance that a warranty claim on the hub might be refused, inside the two-year warranty period. But since the hub, if used daily in the UK, will definitely require maintenance before then, that is not an excuse for doing nothing.

Nexus 8 hubs are not that much worse sealed than Alfine 8 hubs and N8 hubs can fail in a few months of proper winter use. The idea that these hubs are 'no maintenance' devices is surely a product of wishful thinking. No-one who knows anything worth knowing about these hubs says that.

BTW the idea of the shimano maintenance regime is that the grease in the hub is 'refreshed' by the oil bath, i.e. without an occasional oil dunk, the grease dries out and ceases to do anything useful. After dunking the surplus oil is meant to drain out of the workings before they are reinstalled. Thus the oil/procedure they use means the oil isn't present in enough quantity to be sloshing around inside the hub, and it is not the right kind of oil to cling particularly well to bare metal surfaces either. This means that the oil service to shimano hubs has only a very temporary benefit to any part of the hub that doesn't have grease on it; days later any bare metal parts can be essentially lube-free again. Unfortunately the grease they use is pushed out of every bearing anyway and it is pushed out more/faster when it starts to dry out. So IME the pawls etc in the axle centre might stay quite well greased but the actual working parts of the hub (the pinions, pinion bearings, the ring bearing etc) can be so free of grease that they can corrode and seize up unless the lubrication in the hub is significantly improved.

If you put oil into a nexus 8 hub it just leaks out. In an alfine 8 hub, oil ought not leak out at the same rate, but it isn't guaranteed to be retained either. IMHO in both types of hub a good SFG is a better solution than oil.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

zenitb
Posts: 283
Joined: 7 Aug 2018, 9:59pm
Contact:

Re: Shimano Alfine 8 - sealing & servicing

Postby zenitb » 24 Mar 2019, 3:08pm

Brucey wrote:
If you put oil into a nexus 8 hub it just leaks out. In an alfine 8 hub, oil ought not leak out at the same rate, but it isn't guaranteed to be retained either. IMHO in both types of hub a good SFG is a better solution than oil.

cheers


Ok Brucey what would you recommend we buy? My Nexus 8 "ride to work" bike has been going down the muddy canal all winter so I guess the hub needs oil/greasing. Would this stuff (pic) do the job or do you recommend a specific brand of SFG??
Image Attachments
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Brucey
Posts: 35987
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Brucey » 24 Mar 2019, 5:05pm

I know nothing about that SFG so I can't really comment, sorry. I've made my own SFG which works in such IGHs. The closest you can buy to this is the SFG that is used inside land rover front swivels, but

a) I have not used this every IGH and
b) random mixtures of this and different oils/greases may behave in an odd fashion

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Whizz
Posts: 4
Joined: 18 Apr 2019, 8:03pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Whizz » 18 Apr 2019, 8:48pm

This is my first post here, so I'd like to say hi to everyone. I really enjoy the technical content of this forum :)

I have several bikes with IGHs, so I've also been searching for reliable lubrication method. My main commuter bike is equipped with Alfine 8 and I have the most mileage and experience with it.

After about 2000 km I opened the hub to do the first service. I performed the standard Shimano oil dip procedure and on top of that added some more Shimano white grease for IGHs (I admit that was before I discovered this forum...). The hub was running smoothly and the shifting was quick and precise. No leak issues.

After another 5000 km I serviced the hub again and this time around I tried EP 140 GL4 gear oil. It is really thick indeed, so I was hoping that it will provide good lubrication while staying inside the hub instead of leaking. That was around February, so the temperatures were on the low side (about 0-5 degree Celsius). After the service the hub became noticeably more draggy and the shifting deteriorated. Especially, shifting from 4 to 5 became slow. This is a top-normal hub, so shifting from 4 to 5 releases the cable, which is pulled by the spring inside the hub. I would often start pedalling too soon i.e. before the cassette joint rotated to its position. This lead to the hub skipping. I wasn't too happy with the result, but I didn't have time for another service so for the time being I just learned to wait 1-2 seconds before engaging the 5th gear.

As the temperatures rose, I noticed that the shifting improved. Presumably the oil got thinner, which relieved some of the drag in the shifting mechanism. I noticed that the shifting was consistently better during my afternoon commute back home, when the temperature is a few degrees higher than in the early morning.

However, rising temperatures lead to another issue. The hub started leaking, contaminated the brake rotor and ruined a set of brake pads. This time I decided to take action, service the hub and fix the brake before it causes trouble when I actually need it.

In the meantime I got my hands on the Land Rover swivel housing SFG. I serviced two bikes equipped with Nexus 7 hubs and I was very pleased with the results. Hubs were running smoothly and the shifting was good.

So I went ahead and serviced the Alfine with SFG. I combined it with oil dip aiming at a bit thinner lubrication and hoping that there will be less drag and leaks won't be an issue. I ended up putting about 50 ml of SFG into the hub, which was already dipped in the Shimano WB oil (which probably means 10-20 ml of oil clinging to the surface of the internals). Unfortunately, the leaks did not stop. My brake rotor got contaminated again :( As far as I can see the leak is smaller than with the gear oil and the SFG tends to stick better to whatever it contaminated. The leak appears on both drive side and non-drive side. Also, the rate of the leak seems to be going down, but it didn't stop yet. This is happening for 3 days now

The whole situation got me thinking. Could it be that I overfilled the hub and the leak is caused by the excessive SFG being pushed out of the hub while it is moving? Or is it more likely that the slightly thinned out SFG is still too thin for Alfine 8 seals to retain it?

I inspected the LH seal and it looked good to me, but maybe I'm missing something. Is there any particular way to recognize worn seals? I can see that SJS has replacement seals for Alfine 8 at reasonable price, but I'm not sure if I actually need the replacement or I just overfilled the hub with possibly too thin lubricant.

Brucey
Posts: 35987
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Brucey » 18 Apr 2019, 9:33pm

the land rover SFG may well have made a weird mixture with the oil, which made leaks more likely. 70ml total is quite a lot of lube, too. One way of deterring leaks from a centrelock fitting is to wrap PTFE tape around the lockring before fitting it. This means that if some lube bypasses the seal, it may be caught behind the lockring and not leak out onto the disc. IIRC the LH Alfine seal is unlikely to be 100% oil tight. If you leave the bike leaning very far to the left the lube will leak out the LH side if it is fairly runny.

The bad shifting in cold weather may well have been the lube but it could also have been the gear cable; it really doesn't take much cable drag to slow that shift down.

The other thing to bear in mind is that the hub will want to 'breathe' somewhere, i.e. as temperatures change the air in the hub heats up/cools down and expands/contracts accordingly. If this happens where there is lube behind a slightly leaky seal, it will burp lube out of the hub. Leaks on the driveside may pass unnoticed; the lube may come out onto the chain.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Whizz
Posts: 4
Joined: 18 Apr 2019, 8:03pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Whizz » 22 Apr 2019, 6:24pm

Thank you, Brucey. I'm observing the leak rate for now. It went down, but there's still a bit more grease appearing on the LHS after every 10-20 km. Do you have an idea what a reasonable service interval would be on a hub filled with the land rover SFG? In other words, what can possibly happen if the hub isn't attended to in 5, 10 or 20 thousand km? Is the grease going to eventually dry out and lose its properties?

Brucey
Posts: 35987
Joined: 4 Jan 2012, 6:25pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Brucey » 22 Apr 2019, 6:45pm

Whizz wrote:Thank you, Brucey. I'm observing the leak rate for now. It went down, but there's still a bit more grease appearing on the LHS after every 10-20 km. Do you have an idea what a reasonable service interval would be on a hub filled with the land rover SFG? In other words, what can possibly happen if the hub isn't attended to in 5, 10 or 20 thousand km? Is the grease going to eventually dry out and lose its properties?


SFG is less likely to dry out than to leak away; reason being that there is much less thickener in SFG than in thicker grease. When thicker greases 'dry out' they leave the thickener behind. Provided the seals are half-decent the hub should retain enough SFG to run happily for several years. The other side of the coin is that -depending on the conditions of use- the weather might get in. If this happens it will eventually overwhelm the anti-corrosion additives in the grease.

Because the conditions of use and the condition of the seals is a fine balance, it can all swing one way fairly quickly; the seals only don't wear if they are wetted with lubricant. In a used hub they might already be less than perfect (hence the leak of lubricant out of the hub) and thus the hub might be vulnerable to weather ingress regardless of the lube in the hub. The best thing to do is to examine the hub at intervals and act accordingly; if the hub looks OK then maybe you can stretch the service interval out longer than one year.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Whizz
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Joined: 18 Apr 2019, 8:03pm

Re: Shimano Alfine 8 - sealing & servicing

Postby Whizz » 7 Jul 2019, 7:20am

I would like to report back with my experience, which might be useful for others. In my last post, I mentioned that the leak rate went down. Unfortunately, after some time the hub started leaking a lot again. My impression was that it would happen on hotter summer days when I rode fast due to tailwind etc. The bottom line is that I couldn't trust the hub not to ruin the brake pads again.

I decided to reservice the hub. I cleaned the internals with white spirit and put about 25ml of the Land Rover SFG into the shell this time. The hub is running smoothly, the shifting is crisp and precise, and there are no leaks. In fact, I don't recall having any misshifts. I covered about 600 km since that service and had no issues.

zenitb
Posts: 283
Joined: 7 Aug 2018, 9:59pm
Contact:

Re: Shimano Alfine 8 - sealing & servicing

Postby zenitb » 7 Jul 2019, 2:20pm

Whizz wrote:I would like to report back with my experience, which might be useful for others. In my last post, I mentioned that the leak rate went down. Unfortunately, after some time the hub started leaking a lot again. My impression was that it would happen on hotter summer days when I rode fast due to tailwind etc. The bottom line is that I couldn't trust the hub not to ruin the brake pads again.

I decided to reservice the hub. I cleaned the internals with white spirit and put about 25ml of the Land Rover SFG into the shell this time. The hub is running smoothly, the shifting is crisp and precise, and there are no leaks. In fact, I don't recall having any misshifts. I covered about 600 km since that service and had no issues.

Thats a really useful update Whizz. I still have not serviced my Nexus 8 and this looks like a template I could follow :-)