Suspected timing shaft oil seal leak

[yellowfever]

So I’ve had a small subtle oil leak for much of the summer that I’ve been doing my best to ignore whilst I enjoy riding. I’ve limited myself to some regular cleaning and checking after rides to try to trace it/avoid too much oil getting where it shouldn’t. It is getting a bit worse so I can’t really put it off any longer.

I thought it was from the oil line(s) originally, as there was oil around there and further back down clutch side case (where it would logically get blown when riding). After investigating I realised the oil lines had been reversed in error by a pro mechanic way back in 2014 and never noticed by any pros since nor myself until now. This made the clutch side oil line very tight/under strain and of course it can also get disturbed at belt changes. So the idea it may have started leaking from where it connects to the engine seemed plausible.

I’m happy to say that, apart from the unfortunate strain on the shorter oil line, no real issues caused by this error as the oil cooler is not one way flow so swapping feed and return over by mistake makes no difference to cooling. I will however be rectifying this given strain line has been under and also for cosmetic reasons swapping to a longer line from a Hypermotard so I can route both lines past the starter motor and up the alternator side.

[yellowfever]

On further investigation of the oil leak I now think it’s in fact the timing shaft oil seal. The internet, combined with the limited info in S2R 1000 workshop manual, my Haynes manual for my M600 and the Red Baron book, thankfully suggests it’s possible to fix this with the engine in situ.

This also means I get to bring forward my ‘learn how to swap the belts’ moment to now rather than at the major service due next year (tho’ I’ll probably refit the old belts for now as they were only changed in April 2023).

I know there are a few approaches but I’ve got the relevant special tools to lock the camshafts and crankshaft, plus the special tools to be able to remove the belt drive rollers from the timing drive shaft so I can replace the oil seal.

So far I’ve got the belt covers off and it is still looking like the timing shaft oil seal is the culprit. I’ll know more once I get belt drive wheels off the timing drive shaft. Alarmingly there seems to some tiny bits of metal here and there - possibly from the seal (it has a metal part I believe). Hopefully not the timing shaft bearing!

Another suspect for metal bits could be the fixed and mobile tensioner roller bearings, although they all turn with the belts. Both horizontal cylinder ones were replaced in 2016, vertical mobile one in 2014. Vertical fixed roller is still the original form 2006 complete with the weird special 10mm across flats bolt. I believe this can be tricky to remove with the limited access and having to use a 10mm open spanner? But anyway I’ll check all the rollers when the belts are off and replace anything suspect one way or another.

[yellowfever]

Before taking the belts off I wanted to bone up on timing marks and used the rear wheel to rotate the belts and check tensions. After a lot of reading up and experimenting with various approaches I’ve finally got Gates Carbon drive to work consistently with a clip on microphone and adaptor plugged into my iPad’s headphone socket. So I am confident I can set the tension accurately when replacing the belts and what it should be (90-100Hz +/-5Hz for old bels going back on. New belts should be 110Hz +/-5Hz - NB NOT 140Hz the Worksop manual specifies - that’s apparently been superseded). 5mm Allen key method didn’t work on horizontal belt, only just on vertical. Further reading suggests this is normal and I should be using 4mm go/5mm no go for my 1000DS engine, rather than 5mm go/6mm no go.

Next step was to take alternator inspection cover off so I can access crankshaft to turn and lock it with special tools.

Naturally the 4mm Allen head screws n the cover are made of cheese and been tightened way too much in the past (maybe even threadlocked?). Despite penetrating spray and care I’ve already rounded one a bit. Hot air gun, freeze spray and impact driver have only made it worse.

So left to let spray soak in more and tomorrow I try some further options from the following ideas:

Soldering iron to head of hex
Flat punch to hammer Allen shape back
Glue or JB weld Allen key in
Small butane torch on bolt head
Lapping compound in bolt head for more grip
Hammer in a tork bit (!)
Get Screw/bolt extractor (need to drill pilot hole first then thread in extractor counter clockwise until fully home)


ANY ADVICE ON METHODS TO USE/NOT USE GRATEFULLY RECEIVED!

[yellowfever]

https://imgur.com/68XGM9f


https://imgur.com/wknfEWc

Some photos of leak (I hope!)

[Dukedesmo]

Originally Posted by yellowfever

https://imgur.com/68XGM9f


https://imgur.com/wknfEWc

Some photos of leak (I hope!)

Hard to see where it's leaking but are you sure it's not the crank breather or oil pressure switch?

Just that they're both much easier to sort...

[yellowfever]

Hi Dukedesmo, thanks putting photos up in your reply - I put links to imgur but couldn’t figure out how to make actual photo appear in thread…

Yeah oil leak has been a long mystery with a lot of suspects, some scarier than others…I even hoped it was a loose oil filler cap at one point… but from the pattern over several months of cleaning then careful checking for new oil traces after long rides I think it’s probably the timing shaft seal.

But of course oil leaks not that easy to trace especially when they are small and oil can migrate in funny ways, so the source not clear… so I may be wrong. I was convinced it was the wrongly installed oil lines for a while… so I will have a careful look at your suggestions…

[yellowfever]

In the meantime my oil leak was giving my cases a cool magnesium-look vibe

Less fun on my boot/peg when riding…

Right back to trying to free the stupidly tight alternator inspection cover screws…

[stopintime]

Just under/in front of the dual belt wheel is a very typical place for cracks to develop - at least on the smaller case engines. My S2R800 has had that twice. I can't remember if there was much oil though. More likely that the seals leak. Maybe o-rings cylinder/head or cylinder/case.

Very good clean, warm and dry engine, spray foot powder "everywhere", start engine and look for spots where the foot powder gets brown.... is one way to find the leak(s).

[yellowfever]

Stopintime, thanks for the useful tips!

Meanwhile on the stuck screws on the alternator inspection cover I’ve rigged up soldering iron to heat it. Wondering if some kind of threadlock/sealant has been used on these, seemed to be grey traces round edge of screws… hoping heat might help.

https://imgur.com/givgbMf

[yellowfever]

Well that was a bust - 15 mins with 40w soldering iron with flat end of soldering tip against screw and at the end I could touch screw with finger and it was barely warm… could feel heat coming off iron but I guess given thermal mass screw attached to it just doesn’t get hot…

Back to hot air gun and worrying about my paint

[Darren69]

Those alternator covers can be a pain to remove as the screws seize up. Try soaking in plus gas and whacking it with a big rubber mallet. I"m sure you checked the oil pressure sender cos they can leak either at the gasket or through the switch itself. Foot powder is a good call, I was gonna say talc but thats prob easier to apply.

[yellowfever]

Well I got the least damaged screw out with plenty of hot air gun heating. Seems to have something or somethings on the threads/round shank. Possibly copper grease further in and some kind of grey sealant round head?

Other screw Allen socket just got rounded more… barely any grip now…hmmm… back to my list

Soldering iron to head of hex - USELESS
WD 40 - NO JOY
Freeze spray - NO JOY
Hot air gun - NO JOY FIRST TIME, SUCCESS ON LEAST DEFORMED ONE AFTER SECOND TRY

What to try next…

Flat punch to hammer Allen back into shape
Glue or JB weld Allen key in
Small butane torch on bolt head
Lapping compound in bolt head for more grip
Hammer in a tork bit (!)
Get Screw/bolt extractor (need to drill pilot hole first then thread in extractor counter clockwise until fully home)

Any tips welcome!

[Mr Gazza]

Images have to be hosted outside of the site unfortunately.
Go to https://imgbb.com/ follow the prompts to upload your image then select the "BBCode fully linked". copy and paste this line of code into your post and the image will appear when it's posted.

Re your leak, Have you possibly got a slight leak on the right fork leg?
The oil lines should have two little (Viton) O-rings on each spigot which need to be good.
There should also be an ally crush washer beneath the adapter/nipple that screws into the crank case.
If it were me, I would take the short line off once you've got the alternator cover off, (so the oil will be lower.) and swap the line round end for end as it should be to remove any chance that it's under duress. Then is a good time to check the O-rings and maybe just give the nipple an tweak.

Re your stuck screw, I'd start with some coarse grinding paste in the socket head as it can't really do any harm at this stage, although it probably wont work if the head is completely rounded out.
Next on my list would be the Torx bit hammered in. This is not going to do the Torx bit any good, since that will be sacrificed. I think an impact quality bit is going to work best and depending on how it fits the rounded socket head I would be tempted to maybe try and grind/file sharp points onto the Torx "teeth". An impact driver might be worth a try too, but maybe a manual one that you welt with a big hammer? It'll drive the Torx teeth in harder, probably.
Good luck mate, I don't envy you!

[yellowfever]

Thanks Darren, it’s indeed a pain. Hammered screw socket back into shape with punch and quality old Allen key. Now fits tightly again on my Allen socket. Maybe the hammering on the screw will help shock it loose too. Given it another go with loctite freeze spray as it has penetrant too. Will need to wait a bit before trying heat again now as freeze spray warns its v v flammable so need to avoid hot surfaces… once it’s evaporated off I’ll wipe area down and try heat gun again then socket…

[yellowfever]

Well tried again after loctite freeze penetrant spray, hammering Allen key with punch to get tight fit on Allen socket. Then lots of heat. Result, still won’t budge just starts to round again… time to get some JB weld and screw extractors…