Author Topic: ?oil leak  (Read 211 times)

swayzak

  • Jr. Member
  • **
  • Posts: 68
?oil leak
« on: December 09, 2025, 10:50:36 AM »
Hello

As per my other post re chain slippage, I changed the Rohloff oil at the weekend

Rode it into work today for the first time this week & a small pool of black liquid gathered under the back wheel (noticed by a colleague about an hour afer I arrived)

Thing is I lost both new & old grub screws during the oil change (I find it quite fiddly putting them back in, and my eye sight is not what it used to be)

I then found the old one (which had a small amount of sealant on it) so had to use that

So I suspect this was insufficent & the black pool was an oil leak (although it didn't seem particularly oily when I cleaned it up) :(

How critical is the quantity of sealant in preventing Rohloff leaks?

I have purchased replacement kit so the hub should be nice and clean after a 2nd change in 7 days!

Andyb1

  • Full Member
  • ***
  • Posts: 238
Re: ?oil leak
« Reply #1 on: December 09, 2025, 11:53:45 AM »
Sounds like a leak from the screw - a bit of a coincidence to suddenly get a leak from some other place.

What volume of oil did you put in?   The recommendation used to be 25ml but is now half that.   If you had put in 25ml you may be OK?

I am now using blue hylomar gasket sealant on the plug.  It is a non-setting sealant and seems to work well both as a sealer and to stop the plug undoing, and is easily found in UK.  Obviously clean the plug and hub threads first.

swayzak

  • Jr. Member
  • **
  • Posts: 68
Re: ?oil leak
« Reply #2 on: December 09, 2025, 12:08:53 PM »
Sounds like a leak from the screw - a bit of a coincidence to suddenly get a leak from some other place.

What volume of oil did you put in?   The recommendation used to be 25ml but is now half that.   If you had put in 25ml you may be OK?

I am now using blue hylomar gasket sealant on the plug.  It is a non-setting sealant and seems to work well both as a sealer and to stop the plug undoing, and is easily found in UK.  Obviously clean the plug and hub threads first.

Thanks - I used the volumes (and instructions) provided in the kit from SJS cycles

PH

  • Hero Member
  • *****
  • Posts: 2557
Re: ?oil leak
« Reply #3 on: December 09, 2025, 02:25:42 PM »
Put a piece of tape, any sort, over the screw after cleaning around it with isopropyl or something similar.  That won't stop any oil leaking, but it'll make it obvious if that's where it's coming from.  I'm skeptical that enough oil would get past the grub screw to form a pool, but you won't know till you investigate further.
How old is the hub?  My oldest one started leaking after about 15 years, but it's very inconsistent, sometimes it was after a long ride, sometimes when I'd just been to the shops, sometimes not for weeks, I tried to be consistent in the way I parked it, but it didn't make any difference. I occasionally think about getting it fixed, but instead just follow the oil change method in the Living With a Rohloff booklet, basically give it a better flush and drain most of the oil back out,  it's been fine doing that for the last 6 years.
It's up to you, but I wouldn't bother doing another oil change till it's due (I'd also not be buying kits, it's a very expensive way to buy what you need) Rohloff themselves say if all the oil were to leak out there's still enough coating the parts to be fine till the next change.
« Last Edit: December 09, 2025, 02:29:39 PM by PH »

mickeg

  • Hero Member
  • *****
  • Posts: 2977
Re: ?oil leak
« Reply #4 on: December 09, 2025, 06:06:51 PM »
My hub has always had a bad leak.  I have a side stand for my bike, the bike leans slightly to the left when not in use.  And the leakage appears to come out of the EX box.  I am pretty sure that I have a bad internal seal on my Rohloff.  The exploded diagram shows a seal that keeps oil from leaking into the hollow axle for the quick release skewer.  And my skewer is always covered with oil, thus I suspect that seal is what leaks on mine.

I do not understand your post, did you ride your bike and park it at work without the small screw?  If so, a puddle does not surprise me.

I use blue (removable) threadlocker on my Rohloff oil screws.  On this forum, Dave W. (former employee of SJS) commented that what I was using was oil soluble threadlocker and that I should use something else, but I keep using it anyway.  I often put a piece of black electrical tape over the screw after I change the oil, mainly to keep the screw clean so I do not have grit inside where the Allen key goes.




 

swayzak

  • Jr. Member
  • **
  • Posts: 68
Re: ?oil leak
« Reply #5 on: December 09, 2025, 09:35:39 PM »
Put a piece of tape, any sort, over the screw after cleaning around it with isopropyl or something similar.  That won't stop any oil leaking, but it'll make it obvious if that's where it's coming from.  I'm skeptical that enough oil would get past the grub screw to form a pool, but you won't know till you investigate further.
How old is the hub?  My oldest one started leaking after about 15 years, but it's very inconsistent, sometimes it was after a long ride, sometimes when I'd just been to the shops, sometimes not for weeks, I tried to be consistent in the way I parked it, but it didn't make any difference. I occasionally think about getting it fixed, but instead just follow the oil change method in the Living With a Rohloff booklet, basically give it a better flush and drain most of the oil back out,  it's been fine doing that for the last 6 years.
It's up to you, but I wouldn't bother doing another oil change till it's due (I'd also not be buying kits, it's a very expensive way to buy what you need) Rohloff themselves say if all the oil were to leak out there's still enough coating the parts to be fine till the next change.

Thanks

swayzak

  • Jr. Member
  • **
  • Posts: 68
Re: ?oil leak
« Reply #6 on: December 09, 2025, 09:38:59 PM »
I do not understand your post, did you ride your bike and park it at work without the small screw?  If so, a puddle does not surprise me.

No the screw was in (the old screw, with less sealent on it), and fairly tight. I tightened it a bit more (but am aware overtightening is bad)

As I said, the small black pool on the floor beneath the hub seemed more watery than oily, which puzzled me a little...

Andyb1

  • Full Member
  • ***
  • Posts: 238
Re: ?oil leak
« Reply #7 on: December 10, 2025, 08:07:01 AM »
Can you remember at what position the screw was at when you parked up?
Oil would only leak from it if it was at the bottom.
Could the oily residue be some old oil / flushing oil that remained on the hub or spokes when you drained the hub?

I can remember spilling a little oil onto the hub of a motorbike when I changed the rear bevel oil (moto guzzi with shaft drive) and for ages a little oil would get thrown onto the rim even though there was no leak.

Andre Jute

  • Hero Member
  • *****
  • Posts: 4221
Re: ?oil leak
« Reply #8 on: December 10, 2025, 08:07:58 AM »
When my hub was new, I had a frightful moment when there was what appeared to be a pool of oil underneath it. If I'd been living near the supplier or the manufacturer of the bike, I would have delivered it back to them that day with a rocket and a demand they fix it at their own expense. Fortunately for my dignity, I live in Ireland and there was no instant means available to return the bike to Germany.

On investigation over several occurrences of the disturbing event, I noticed a preponderance of water and very little oil in the small pool. Since the hub had not been submerged, I started wondering about environmental factors. The bike was standing in a passageway in my town house, near an outside door of wood but a large half-circle of glass over the door, causing the bike to be alternatively in sunlight -- it was a pretty hot summer shading into a muggy autumn -- and colder shadow. Cycles of heat and cold could account for a small pool of water on the stone floor. We also saw it in the winter, when the heating goes off at night.

In those days I filled with the recommended 25ml of Rohloff's own All Seasons Oil.

Someone on the forum mentioned to someone else in another matter that the Rohloff vent is through the axle.

So here I then had two facts which together would account for a pool of water with a little oil in it.

Over time, as I understood more and more about Herr Rohloff's extreme devotion to the Engineer's Religion, also called Cover Your Ass, which in this case was practically expressed as, "12ml in the hub is enough for me, but thee are required to put in 25ml."

I filled with less and less oil and eventually the problem disappeared when I got down to filling with 16ml of oil. It's years since I last saw evidence of the "leak". These days I fill with 14ml to allow for spillage because measuring and inserting the permitted 12ml isn't a certain procedure in domestic conditions when you don't have the hub on a bench before you.

*****

It is a well known fact that once the gears inside a Rohloff box are coated with the correct oil, it's good to go until the next service interval at 5000km/3000m or one year, whichever comes first. Extra oil swishing around is superfluous.

*****

My advice is therefore not to panic, to perform a full service with 14ml of Four Seasons Oil, ending with fitting a new stud in the Rohloff oil port, and to watch whether anything comes back out in the next few days.

*****

You must take your own counsel with an expensive hub, but I would not hesitate so soon after putting fresh oil in the hub, if waiting for a service kit or stud to arrive, to ride the bike as long as the piece of tape PH advises is across the port (more to keep dust out and stop oil getting on the braking band of the rim, than to protect the gears against running dry). The logic here is that even the Cleaning Oil is actually also a running oil, specifically for very cold ambient conditions, and some of that, plus some of the All Seasons Oil that you put in, will be sticking to the gears.

Good luck.
« Last Edit: December 10, 2025, 08:09:51 AM by Andre Jute »

swayzak

  • Jr. Member
  • **
  • Posts: 68
Re: ?oil leak
« Reply #9 on: December 10, 2025, 08:44:07 AM »
Thanks for that - reassuring!

After further inspection this morning, I found v similar black watery fluid underneath the Ex-box so suspect the "leak" was coming from here (not the port on the main hub

However whilst investigating this I stupidly put the shifter in gear 1 (not 14) before detaching the ex-box and cleaning it a bit

Now it won't reattach properly - how do I realign things to gear 14 so I can attach it back correctly?

Can I push the ex box on as far as possible then use shifter to move the ex-box to gear 14? Or do I need to use a spanner on the ex-box?

JohnR

  • Hero Member
  • *****
  • Posts: 723
Re: ?oil leak
« Reply #10 on: December 10, 2025, 09:55:24 AM »
From memory, use a spanner to turn the gears to one of the limits, turn the shifter to the corresponding limit and then fit the ex-box. Finally check if you have the full range of gears.

I've had the leakage problem in the past. You may want to draw off a little oil from the hub. As already noted, there doesn't have to be a lot of oil in the hub to be able to keep everything lubricated. There's the risk that when doing a flush and refill of ending up with more oil in the hub than at the start unless you've been patient in trying to extract every drop.

swayzak

  • Jr. Member
  • **
  • Posts: 68
Re: ?oil leak
« Reply #11 on: December 10, 2025, 10:21:12 AM »
Thank you

It sounds from what eveyone has said that it's probably not worth doing a repeat oil change 7 days after the previous change to cure this issue (apart from peace of mind maybe)?

If I'm looking at the inside surface of ex-box face on, do I turn the ex-box nut clockwise or anti-clockwise for gear 14?
« Last Edit: December 10, 2025, 10:23:20 AM by swayzak »

PH

  • Hero Member
  • *****
  • Posts: 2557
Re: ?oil leak
« Reply #12 on: December 10, 2025, 10:56:40 AM »
If I'm looking at the inside surface of ex-box face on, do I turn the ex-box nut clockwise or anti-clockwise for gear 14?
I can't remember, but there's no need to.  You can change gear with an 8mm spanner while the wheel is in the dropout,  turn it to one end, turn the pedals, turn it to the other and you'll know.  I frequently forget to change gear before disconnecting and do the above, it takes a couple of seconds. 

mickeg

  • Hero Member
  • *****
  • Posts: 2977
Re: ?oil leak
« Reply #13 on: December 10, 2025, 11:59:39 AM »
When I put my EX box together and do not get all gears, say if the shifter only goes from 1 to 12, I put the hub into that gear the shifter says is gear 12.  But I know that I actually put it in the highest gear that way, so I take the cover off the EX Bos, then turn the shifter to 14 and reassemble.

Or if the shifter only worked from gears 4 to 14, same concept.  Set it at 4 which is the lowest gear, take the cover off the EX Box, set to gear 1, reassemble.

Takes less than two minutes, no tools needed.

UKTony

  • Full Member
  • ***
  • Posts: 186
Re: ?oil leak
« Reply #14 on: December 10, 2025, 01:12:41 PM »


If I'm looking at the inside surface of ex-box face on, do I turn the ex-box nut clockwise or anti-clockwise for gear 14?
The simple answer is anti-clockwise to get to gear 14.