Oil leak

[avdave]

I've noticed today an oil leak from my hub between the sprocket and the hub. The bike has been kept upright and it hasn't been in an aircraft which I know can cause leaks. I've a new chain waiting to go on and have the tools ready to reverse the sprocket but was hoping the chain would last until the next oil change which is due in August when the hub will be 3 years old. So are there any seals between the hub and sprocket which might need replacing and which might explain the leak.
Any advice will be welcome

[stutho]

Hi avdave,
There is a seal between the sprocket and the hub but it can't be replaced without a specialist tool - I wouldn't recommend doing this yourself.  How much oil are we talking about?

stutho 

[avdave]

Probably about 5ml or so on the floor at work yesterday when I went to leave for home.

[stutho]

That is a lot.  It may be worth removing the sprocket and have a visual inspection of the seal and  a bit of a clean up.

[avdave]

The bike has now been sitting in the garage for 2 days as I have been away and there has been no further sign of any oil leaking. I'm wondering if it might be linked to a ride at the weekend where a fair amount of straw got caught up around the rear sprocket. As it wasn't causing any problems riding I didn't clear it out, so different from when it would jam my derailleurs  on the old bike. When I inspected the hub after the oil leak there was still some traces of chewed up straw between the  sprocket and the hub which I cleared out so I'm wondering if it might have got past the oil seal and acted as a wick causing the  leak. I'll order some new oil and take your advice stutho and take the sprocket off for a closer inspection as it could also do with reversing soon anyway.

[expr]

Without wanting to tread on anybody's toes so to speak, there is also another seal that it could come from which is part hidden by the alluminium flat face nut on the sprocket side. It is a sealed bearing that has a fragile seal face on it only made from thin rubber. If a foreign body gets between the nut and seal face, then the seal face can become permanantly damaged, which will require stripping the hub down and replacing the bearing, there are actually two face to face but the outer one gives the seal. This is easy to do if you are comfortable with stripping down the hub.

Just for reference the bearing type is an SKF 6001-2RSH  this is from their Explorer range4 102d

Here is the link for the hub seal replacement another easy task if you feel comfortable 

http://www.rohloff.de/en/download/video/workshop/hub_seal_replacement/index.html

THE SOUND HAS BEEN TURNED OFF AS IT'S IN GERMAN !

[stutho]

WARNING to anyone about to remove the flat  nut on the drive side.  THIS is EXPLICITLY mentioned as a way to invalidate you Warranty  - it's you call, good luck!!!

[expr]

Sorry stutho, didn't realise the implications of my help. As you say "it's your call" and I think your right I don't want to be responsible for a 'have a go' diy'er just having a look only to find their warranty out the window!  Just wanted to point out the fact that it could be a possible place for bleeding of oil. Also useful information for people who's 1 year warranty had expired!

[stutho]

No harm no foul.  Re the 1 year warranty Rohloff have a reputation for fixing there hubs for free even well after the stated 12 months (If you are the original owner)   

[expr]

Point taken, I had heard similar tales of rohloff sorting issues out past the warranty, this is in their best interst understandably to uphold the reputation of 'faultless' and you can only admire their intent.

All the best Dave.

btw have you managed to sort any extra server space with sjs at all. RE pics!

[avdave]

Thanks guys, there has been no sign of any more oil leaking and the hub is running perfectly. Expr I've been reading your contribution to the sprocket reversing thread and I think I may as well order a new sprocket to have ready in case mine shows signs of wear when it's time to replace the chain. The bike is used off road all year round as a commuter so I would imagine there is a good chance that the outer face is worn. I'll take a look at the hub seal video, if Rohloff supply a tool for doing it and show you how to on the website then I'm happy enough to do it myself if and when it becomes necessary. 

[expr]

No problem at all, I have put a link on one of my posts regarding the fitting of the hub seals, it's directly off the rohloff website under videos / workshop here is the link again

http://www.rohloff.de/en/download/video/workshop/index.html

Thanks for your reply

Dave

[Gog yn y De]

Without wanting to tread on anybody's toes so to speak, there is also another seal that it could come from which is part hidden by the alluminium flat face nut on the sprocket side. It is a sealed bearing that has a fragile seal face on it only made from thin rubber.

This is where my hub has started to leak from today. I noticed it when I put the bike onto the roof rack and saw that it had dripped oil on to the rim at during each of the 4 checkpoints of todays 200km audax event. I gave it a wipe while I went it for a drink and upon my return it was ready to start dripping again. The bike/hub (Raven Sport Tour) is about 8 months old and had covered about 1800km. What should I do?

[expr]

Hello Gog yn y De,

Ok first thing, the hub has several places from where it can leak from around that area. I am going to assume that you have a quick release wheel clamp with the hollow hub.

On the drive side there are three places that the oil can come from,

1. From around the inner or outer part of the hub seal
2. From inside the hub axle itself (where the QR sqewer) goes through.
3. From around the hidden driver bearing face sheild or from around the bearing itself

Has this just started to happen and have you ever done an oil change.

First thing that I would do is take the wheel off the bike, remove the QR sqewer and have a look to see if there are any traces of fresh oil on it or any oil in the hollow axle, if that is wet then pass a small bit of tissue through the axle to clean off, go for a ride and recheck later for more oil.

The hub uses the axle naturaly for oil breathing but will give cause to excessive leaking if the hub has to much oil in it, have you checked oil level at the oil change ?

Next thing to check is, does the oil come from the hub side of the sprocket or the flat alluminium lock washer side of the sprocket, if it's the hub side then its allmost certain the hub lip seal, if it's the alluminium nut side then it's looking like the face sheild on the bearing has become ineffective, or its leaking from around the driver bearing itself.

The hub will not show up oil leaks as much stood upright so tipping it on the drive side may show up any potential leaks more.

Doing the tests should show up the fault, but as you are still in the warranty period it's your call on WHO  actually fixes the problem. Doing the driver bearings is relativly easy if you are competent at such tasks and have the tools, the bearings that were on my hub I changed for the skf explorer range which are better quality.

The face sheild in my opinion is a potential problem if you are likely to get things stuck around the sprocket as its only a very thin protector, which for the most part the nut protects it but if things get caught up between the nut and the axle then its a possible issue.

I have put a link to some pictures on a previous thread, it shows the driver bearing's. there are two pages its on the second page, quality of pictures not very good sorry, and most of them are showing the bottom bracket thread insert modifaction that I did.

http://www.photobox.co.uk/album/104559156
let me know how you get on !

[Gog yn y De]

Thanks for the info, expr. Conclusion at the moment, having spoken to SJS Cycles, is that it needs to go back for repair...