Degreaser for Nexus 8 hub gears

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syklist
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Joined: 19 May 2008, 6:43pm

Degreaser for Nexus 8 hub gears

Post by syklist »

I want to service a couple of Nexus 8 hubs. I was planning to remove the internals, degrease and then re-lubricate the gear nechanisms before re-assembling the hubs. I can get hold of the Shimano oil dunk kit and grease, but I was wondering if anyone has any recommendations for a suitable degreaser.
So long and thanks for all the fish...
Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Degreaser for Nexus 8 hub gears

Post by Brucey »

Paraffin works pretty well.

However I would only degrease the hub entirely if the whole thing was going to be stripped down; if you are not careful you can wash all the grease out of the RH hub bearing and then it may suffer in service through lack of lube.

BTW I am far from convinced that the Shimano grease and oil is the best thing for these hubs. I've seen a hub that had just been serviced in the approved fashion. Most of the oil had leaked out of the hub and many parts of the hub were no longer coated in grease; the oil had seemingly removed it. There were lumps of grease cast into corners of the hub where it could do not good. I'd suggest that if you use the oil dunk technique, it should be repeated on a very regular basis.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~
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syklist
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Joined: 19 May 2008, 6:43pm

Re: Degreaser for Nexus 8 hub gears

Post by syklist »

Thanks for the reply. Both hubs have become a little stiff after sitting around unused for a year. That is why I was thinking of degreasing first. I will try a dunk and re-grease first.
So long and thanks for all the fish...
crg
Posts: 99
Joined: 11 Oct 2021, 10:33am

Re: Degreaser for Nexus 8 hub gears

Post by crg »

Brucey wrote: 30 Apr 2015, 12:03am Paraffin works pretty well.

However I would only degrease the hub entirely if the whole thing was going to be stripped down; if you are not careful you can wash all the grease out of the RH hub bearing and then it may suffer in service through lack of lube.

BTW I am far from convinced that the Shimano grease and oil is the best thing for these hubs. I've seen a hub that had just been serviced in the approved fashion. Most of the oil had leaked out of the hub and many parts of the hub were no longer coated in grease; the oil had seemingly removed it. There were lumps of grease cast into corners of the hub where it could do not good. I'd suggest that if you use the oil dunk technique, it should be repeated on a very regular basis.

cheers
What is the RH hub bearing?
Jdsk
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Joined: 5 Mar 2019, 5:42pm

Re: Degreaser for Nexus 8 hub gears

Post by Jdsk »

That was 7 years ago.

Brucey isn't able to post now.

Jonathan
ElCani
Posts: 537
Joined: 5 Mar 2015, 11:24am

Re: Degreaser for Nexus 8 hub gears

Post by ElCani »

crg wrote: 29 Aug 2022, 7:09pm
Brucey wrote: 30 Apr 2015, 12:03am Paraffin works pretty well.

However I would only degrease the hub entirely if the whole thing was going to be stripped down; if you are not careful you can wash all the grease out of the RH hub bearing and then it may suffer in service through lack of lube.

BTW I am far from convinced that the Shimano grease and oil is the best thing for these hubs. I've seen a hub that had just been serviced in the approved fashion. Most of the oil had leaked out of the hub and many parts of the hub were no longer coated in grease; the oil had seemingly removed it. There were lumps of grease cast into corners of the hub where it could do not good. I'd suggest that if you use the oil dunk technique, it should be repeated on a very regular basis.

cheers
What is the RH hub bearing?
Jonathan is correct, sadly. Brucey is much-missed!

The “RH hub bearing” is the right hand side ball bearing via which the hub spins on the axle. It’s well-buried within the workings of the hub, hence Brucey’s concern about it being suitably re-lubricated after degreasing.
crg
Posts: 99
Joined: 11 Oct 2021, 10:33am

Re: Degreaser for Nexus 8 hub gears

Post by crg »

Jdsk wrote: 29 Aug 2022, 7:23pm That was 7 years ago.
Brucey isn't able to post now.
Jonathan
Asking in this thread will keep the info in one location.
Brucey continues to be a resource.
ElCani wrote: 29 Aug 2022, 7:35pm
crg wrote: 29 Aug 2022, 7:09pm
Brucey wrote: 30 Apr 2015, 12:03am Paraffin works pretty well.

However I would only degrease the hub entirely if the whole thing was going to be stripped down; if you are not careful you can wash all the grease out of the RH hub bearing and then it may suffer in service through lack of lube.

BTW I am far from convinced that the Shimano grease and oil is the best thing for these hubs. I've seen a hub that had just been serviced in the approved fashion. Most of the oil had leaked out of the hub and many parts of the hub were no longer coated in grease; the oil had seemingly removed it. There were lumps of grease cast into corners of the hub where it could do not good. I'd suggest that if you use the oil dunk technique, it should be repeated on a very regular basis.

cheers
What is the RH hub bearing?
Jonathan is correct, sadly. Brucey is much-missed!

The “RH hub bearing” is the right hand side ball bearing via which the hub spins on the axle. It’s well-buried within the workings of the hub, hence Brucey’s concern about it being suitably re-lubricated after degreasing.
Is that 12 in the attached photo? How does one regrease this RH hub bearing?
Attachments
Nexus SG-8R36.jpg
ElCani
Posts: 537
Joined: 5 Mar 2015, 11:24am

Re: Degreaser for Nexus 8 hub gears

Post by ElCani »

crg wrote: 29 Aug 2022, 8:38pm
Jdsk wrote: 29 Aug 2022, 7:23pm That was 7 years ago.
Brucey isn't able to post now.
Jonathan
Asking in this thread will keep the info in one location.
Brucey continues to be a resource.
ElCani wrote: 29 Aug 2022, 7:35pm
crg wrote: 29 Aug 2022, 7:09pm

What is the RH hub bearing?
Jonathan is correct, sadly. Brucey is much-missed!

The “RH hub bearing” is the right hand side ball bearing via which the hub spins on the axle. It’s well-buried within the workings of the hub, hence Brucey’s concern about it being suitably re-lubricated after degreasing.
Is that 12 in the attached photo? How does one regrease this RH hub bearing?
Yep. I believe special tool is required to remove the bearing. What I did (via a recommendation from Brucey on another thread) was separate the two main clusters of the hub internal, then use Land Rover front swivel semi-fluid grease to lubricate everything. The fluidity of this stuff allows it to spread around the hub in use, lubricating all the bearings and pawls and whatnot. :)
crg
Posts: 99
Joined: 11 Oct 2021, 10:33am

Re: Degreaser for Nexus 8 hub gears

Post by crg »

ElCani wrote: 29 Aug 2022, 9:35pm Yep. I believe special tool is required to remove the bearing. What I did (via a recommendation from Brucey on another thread) was separate the two main clusters of the hub internal, then use Land Rover front swivel semi-fluid grease to lubricate everything. The fluidity of this stuff allows it to spread around the hub in use, lubricating all the bearings and pawls and whatnot. :)
Can you point me to the other thread?

Can the RH bearing be greased using a syringe and large-bore needle? Need a channel 2mm in diameter.
ElCani
Posts: 537
Joined: 5 Mar 2015, 11:24am

Re: Degreaser for Nexus 8 hub gears

Post by ElCani »

viewtopic.php?t=93935

The mentions of SFG begin around page five but the whole thread is worth a read.

My understanding is that an SFG will migrate to the RH bearing in use, but obviously it’s worth getting it as close as you can when you first apply it, using whatever method you can.
Gazelles
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Joined: 10 Sep 2022, 6:51am

Re: Degreaser for Nexus 8 hub gears

Post by Gazelles »

I have had good success with washing out the hub with minerals spirits / lighter fluid. I mounted the shaft into a battery drill and then moved the mechanism while dunked in the washing fluid. A magnet outside the metal can collected quite an amount of steel particles. I let the washing liquid drip of and dry over night and then move the mechanism again with the drill in car gerbox oil and let it drip of again. I tried to apply grease to the RH bearing but I can't tell for sure how well I reached it. Then I applied grease to the bearings and mounted the mechanism back into the shell. Two hubs run very well again so I'm happy with the method. Care has to be taken not to dismantle the right hand side of the mechanism. I have done this once and had to dismantle and reasemble the complete mechanism which was much more complicated than the usual maintenance job.
crg
Posts: 99
Joined: 11 Oct 2021, 10:33am

Re: Degreaser for Nexus 8 hub gears

Post by crg »

Gazelles wrote: 7 Dec 2022, 5:12pm I mounted the shaft into a battery drill and then moved the mechanism while dunked in the washing fluid.
Does this spin the hub internals as a unit or operate the hub?
Gazelles
Posts: 45
Joined: 10 Sep 2022, 6:51am

Re: Degreaser for Nexus 8 hub gears

Post by Gazelles »

At first it only spins the hub internals as a unit. But when you hold the outer shell of the gear assembly this starts to set the planetary gears in motion. This is when much of the swarf is loosened and flushed outside. The bigger amount of swarf is from the washing (second picture), the smaller from moving the hub internals in oil (first picture).
Attachments
Stahlspäne aus dem abgetropften Öl.jpg
Stahlspäne aus dem Wasch-Benzin.jpg
crg
Posts: 99
Joined: 11 Oct 2021, 10:33am

Re: Degreaser for Nexus 8 hub gears

Post by crg »

Gazelles wrote: 8 Dec 2022, 2:42pm At first it only spins the hub internals as a unit. But when you hold the outer shell of the gear assembly this starts to set the planetary gears in motion. This is when much of the swarf is loosened and flushed outside. The bigger amount of swarf is from the washing (second picture), the smaller from moving the hub internals in oil (first picture).
Is the solid ring in the second photo, swarf or the magnet?
Gazelles
Posts: 45
Joined: 10 Sep 2022, 6:51am

Re: Degreaser for Nexus 8 hub gears

Post by Gazelles »

The magnet is outside of the steel sheet metal bottle - so this is just the magnetic part of the swarf. The hub has probably been run quite a lot ok km without any maintenance. A lubrication method that leaves all this swarf inside can't be very good IMHO.
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