Triumphrat

DEcosse · 07-17-2010, 04:45 AM

I have been chasing the source of an oil leak since I installed this Daytona engine. It has been driving me nuts!

It leaks under crankcase pressure - really noticed it when at the dyno the other day. If parked, there are a few drops initially (the residual) and then it stops.

Think I finally have the source - and it's a bizarre one!
Thought I would share - maybe someone else chasing elusive oil leak.
When I removed the sprocket cover, you could see the trace of oil running all the way down the flange - nothing above that one bolt hole.
It would run off the bottom rear corner of the sprocket cover & drip onto the side-stand switch, then onto the floor.
My last 'guess' (seemed like calculated reasoning at the time!) was that is was coming from the gear selector shaft (also shown in these pics, adjacent to that screw hole). That o-ring was replaced a few months back. Really thought that was it!
But in these images you can see 'muck' around that, but no virgin oil, compared to that on the flange.

These pictures seem pretty conclusive that is coming from the threaded hole! You can actually see the puddle of clean oil in the bottom of it. After the pictures, I took a cotton-bud and could wick it out - definitely originating from in there.
I didn't take picture of this, but there was also oil in the bushing at that location in the sprocket cover.
Not sure yet what to do about a permanent fix - for now I put thread sealant on the screw, we'll see what that does.

Speed3 · 07-17-2010, 08:22 AM

The fix, according to guys over in JOE, is to get the bottom of the hole clean of any oil, and load it with RTV. The sidestand bolt holes are known to leak as well, and have been solved this way. Mystery leaks are a PITA!

zelatore · 07-17-2010, 09:40 AM

Hope you found the solution to your leak.

Slow leaks and intermittent noises. Two things I hate trying to find!

BTW, I see you're in the east bay. What dyno shop were you using?

Rockit · 07-17-2010, 12:21 PM

Similar problem on a different bike I have.

Clean with brake cleaner than use red Hi-Temp silicone. If the bolt bottoms out cut the bolt and leave a small air pocket for the silicone.

DEcosse · 07-17-2010, 12:47 PM

Quote:

Originally Posted by zelatore

... BTW, I see you're in the east bay. What dyno shop were you using?

Jim Higgins at JT&S Performance up at Infineon Raceway - super guy, very meticulous attention to the whole spectrum. Can highly recommend him.
I'll be doing a separate report on that.

Alanon2wheels · 07-23-2010, 10:06 PM

I hate those mystery oil leaks too. I think thread sealant should be fine as a permenent fix. If the bolt has a flange you could also use a copper washer. There is probably a hairline crack in the bottom of the hole. I've never had the best luck using any kind of RTV to seal oil leaks. You have to get the area absolutely clean or it won't seal. Good luck.

DEcosse · 08-03-2010, 10:15 PM

Post script - so I finally fixed the leak (I believe!) - except it was NOT what I thought in the opening post!

I had sealed up that threaded hole with thread sealer on the bolt. But problem was not resolved - before long it was dripping again.
Pulling the afore-mentioned suspected bolt showed that the selaer had indeed done its job - but done it to keep oil from leaking in, not out! Bolt and hole were bone dry despite oil again all around the flange. I wouldn't have thought oil would have flowed up to fill the hole per the pics, which is what made me think it had to be originating from there.

But no - it was actually what I had originally determined - and already attempted to repair - the o-ring on the fork selector shaft.
So combo of oil in the threaded hole above the shaft - and fact that the shaft seal had been replaced, said it had to be coming out of the threaded hole. So much for that determination!

It is possible to pull that shaft out far enough to replace the o-ring without any problems inside the transmission - just be sure not to pull it too far!!!! Equally, need to be sure not to push it back IN too far (ask me how I know that - from the first replacement!)

Anyway, I pulled it out to where the o-ring protruded past the case and indeed could see fresh oil on the shaft on the 'wrong' side of the o-ring - so convinced it was leaking from there.
Ordered new o-rings (couple extra) - they are 9 x 12 x 1.5 mm

But it was bugging me to do something rather than leave it for a few days waiting for them: also knowing it had already been replaced with OEM ring; found my local autoparts store had a 8 x 12 x 2mm - so thought I would try that to see how it fit. At $2.50 for a bag of 8, was worth trying. My theory was stretching the ID to fit the shaft's 9mm groove, would 'thin' the cross-section - so this should result in both a snug fit on the shaft and something slightly more than the 12mm 'spec' OD
The OD's are the same un-installed at 12mm - the 'new' ID is smaller in the 8 x 12, but when stretched to fit the 9mm shaft groove, that would also increase the OD - however 'thinning' the CSA at the same time, which would reduce the OD i.e. 8 + 2 + 2 = 12; but when stretched, 9 + (<2) + (<2) = <13.
I should have thrown my calipers over the O'ring to get the new OD after it was installed. But I would estimate maybe that would be 12.5mm, slightly bigger than the 9 x 12.
Having the extras was quite a bonus - I had also learned from the first go-around, that installing this is a pain - the o-ring has to transition past the first groove for the retaining clip and of course the o-ring just drops right in there! So I put a couple of o-rings into that groove first, then installed the 'actual intended' ring over those - the initial rings eliminated the final ring from dropping into the slot and it was easy to slip it over those and onto the further part of the shaft and into its proper slot. (I left the 'guide' rings in place until after the test fit, in case it had to come out again)
I started to push the shaft in to the seat the o-ring past the end of the casing - I was pleased to feel resistance, indicating it should seal.
Learning from the previous experience, this time I clamped set of vice grips on the end of the shaft and rotated it back & forward as I pushed it gently in - it went in snugly, which again was a good indication.
I was pleased at the way it felt - enough resistance to suggest a good seal would prevail.

I only did a quick 30 min ride, but upon return I pulled the sprocket cover and it was bone dry - not so much as a film present.
VERY encouraging!

The correct 9 x 12 o-rings arrive tomorrow, but I think I'm going to leave the 8 x 12 in there unless leak re-appears.

It's hard to say what fixed it - was it poor installation of the correct size o-ring (that first groove makes it a pain to install)
Although why was the original leaking?
Possible tolerance issue on the shaft or the casing bore?

Sparti · 08-09-2010, 07:14 AM

DEcosse, i have had exactly the same issue check out this post of mine

http://www.thespeedtriple.com/Forums...?topic=17508.0

The thing is i have no leak whatsoever around my my gear shaft. I thoroughly cleaned the whole area and after every ride pulled the cover off and there was leakage around the bolt hole in question. I've in the past, stripped the thread in the bolt hole in question for the first 1/3 of the bolt hole and feel this is where the oil is coming from.

I haven't had any more leaks since using the orings over the bolt.

Ill keep you posted.

DEcosse · 08-09-2010, 12:53 PM

Quote:

Originally Posted by Sparti

DEcosse, i have had exactly the same issue check out this post of mine...

Note that mine ended up NOT being the bolt-hole as I had suspected - as per post #7, I confirmed it was definitely not the bolt-hole (by using a sealant) and that it was definitely the o-ring on the selector shaft seal. Although I got that beautiful (supposedly confirming) picture of the oil in the bolt-hole, oil was actually flowing into that, not out of it, as it turned out.
For the first time ever, I can confirm it is now drip-free after the o-ring fix.

Sparti · 08-09-2010, 05:35 PM

Quote:

Originally Posted by DEcosse

Note that mine ended up NOT being the bolt-hole as I had suspected - as per post #7, I confirmed it was definitely not the bolt-hole (by using a sealant) and that it was definitely the o-ring on the selector shaft seal. Although I got that beautiful (supposedly confirming) picture of the oil in the bolt-hole, oil was actually flowing into that, not out of it, as it turned out.
For the first time ever, I can confirm it is now drip-free after the o-ring fix.

Dec, can you post pics of the exact area that was leaking - would be very helpful.