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Morning!

i read a few articles about how to clean and lube the nexus 8, but i didnt found a good degreaser here i can leave my internal hub inside for a hour at least to breakdown the old grease, which degreaser i should to use? After i would like to do the bath dunk with Shimano Oil but it is a quite expensive for 1L (£64), is any one can recommended a good oil and cheaper?

thanks

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  • Can i use manual transmission fluid instead? the RedLine fluid?
    – Pypoka
    Commented Nov 14, 2017 at 10:39
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    I see from your other comments that you just bought this thing. It's a little early to be thinking about cleaning and lubing it. The factory lube should last for a while.
    – Mike Baranczak
    Commented Nov 14, 2017 at 17:52
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    Read the instructions for your hub. I doubt it says to use degreaser, because its an oil bath gearbox. You drain the old oil out then replace it. You never ever degrease an oil bath. And yes - Shimano oil is expensive, but not using it will void your warranty.
    – Criggie ♦
    Commented Nov 16, 2017 at 7:35

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Don't use degreaser on the insides of an IGH! Not! Ever!

For Shimano Nexus/Alfine you are supposed to use the same oil for cleaning and lubrication.

For Rohloff there is a separate cleaning oil which I think has lower viscosity than the lubrication oil.

Also you replace the oil at most once a year or every 5000km, not more often. Some hubs might need their very first oil change earlier, like after 1000km.

This assumes going though the bleeds nipples like normal people.

If you are going to take the hub apart completely (not just remove the gear block from the housing) this doesn't necessarily apply, but taking the hub apart is not something even good bicycle mechanics do. It never makes economic sense. If taking it apart and fixing it is cheaper to you than having it replaced, then it didn't make economic sense to buy it in the first place and you should have gone with something cheaper, simpler, more mechanically elegant and more maintenance intensive - as in, much less maintenance than taking apart and fixing an IGH.

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  • When doing a complete disassembly and overhaul, metal parts can be cleaned with a degreaser - of course, lubricating it afterwards.
    – bikegremlin
    Commented Oct 26, 2018 at 6:02
  • @ReljaNovović Oh, yeah, you can do that without necessarily doing damage. It's just not a good idea in general.
    – Nobody
    Commented Oct 26, 2018 at 10:13
  • You think that using oil for cleaining the old grease from Nexus hubs is a better choice? Are there any possible downsides of degreasing if it's all re-lubricated afterwards? Talking about disassembled parts, of course.
    – bikegremlin
    Commented Oct 26, 2018 at 10:17
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    @ReljaNovović No, sorry I wasn't clear. If you have taken them apart so completely that you are sure there are no plastic parts somewhere in the part you want to degrease and you are sure you won't miss any part while regreasing (say a needle bearing somewhere in the middle of the assembly), then the usual degreasers are fine. Mostly I don't think disassembling them is a good idea at all and if you don't do a full disassembly then degreasing is not a good idea because precisely you are likely to miss some part when regreasing or damage a part you didn't know was there.
    – Nobody
    Commented Oct 26, 2018 at 11:53
  • Agreed. As for disassembly, my experience is that hubs with no service history (known) are best completely disassembled and inspected on the first service, then re-lubed. For regularly serviced ones, with appropriate lubricants, this is not necessary.
    – bikegremlin
    Commented Oct 26, 2018 at 12:09
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As for degreaser: petrol works very well, but it is highly flammable, so make sure you use it outside, taking all the needed precautions.

Diesel is less flammable and works fine too.

Odourless mineral spirits are the "norm" for this use.

EDIT: if it's not obvious - use degreaser only if disassembling the hub completely, to clean all the (metal) parts. Don't use petrol on plastic parts (to be on the safe side). And don't just dip the hub into degreaser if it won't be completely stripped, cleaned, re-lubed and then assembled. Make sure all the degreaser is removed before reassembly (petrol is the fastest to dry, then mineral spirits).

As for oil, synthetic automatic transmission fluid (ATF) is considered a good alternative to Shimano's "original" oil. Mobil 1 ATF, or any other you can find in local stores, or on line.

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