Hi. I have Monster S2R 800, 2005 for two years. One of the previous owners converted the wet clutch into a dry one. Constantly I have an oil leakage issue. In a functional way, the dry clutch works OK. When oil first leaked through the main shaft I changed two O-ring on pushrod, lip seal in the hollow drive shaft and lip seal in tightening nut. Pushrod is straight. After 700 km the same oil leakage (through hollow drive shaft) happened again. I repeated mentioned procedure and changed all seals again. The same problem appeared 800 km later. Does anyone have any suggestions about possible solutions for my problem? What could be the problem?
Do you have some photos of the issue? Is the oil travelling along the pushrod and then spraying out inside or is it the case its the big oil seal behind the clutch basket that's leaking? How bad is the leak? How are you removing the pushrod? From the clutch basket side or from the clutch slave cylinder side? It should ideally be removed and reinserted from the slave cylinder side but in the real world that's not always feasible as it is prone to sticking itself in the bearing on the clutch pressure plate. From my personal experience I've had slight leaks due to oil migrating along the pushrod and I also changed a complete clutch including the basket only to find there was a slight leak from the big oil seal behind the basket, could see where it had sprayed out once the basket was out, so stripped out the oil seal and replaced it. In both cases the leaks were minimal and in no way dod they affect the riding of the bike.
West Cork Paul, thank you your replay. Since this inconvenience happened to me several time in a row, I twice dismantled the clutch and checked also big seal behind the clutch basket. It is OK. Oil is leaking through hollow main shaft through which goes pushrod. When I removed pressure plate the inner section of central hub was full of oil (if big seal would be the problem, inner section of central hub would be dry). My dry clutch is covered by carbon cover to prevent oil spraying in case of clutch failure!? The carbon cover has two breathing holes through which leaked oil runs out!? In case of leakage oil quantity is quite significant, so big that right side of rear tyre is oiled! That is the main reason why I want to resolve this problem. Thank you for any suggestion. Do you maybe know someone who had similar problems and resolve it?
Is the problem that the push rod is spinning and destroying the seals ? If so check that the thrust bearing in the pressure plate is free and in good condition, or as a last resort you could convert to an anti-rotation clutch push rod as used on the later models for this reason.
@Brijon is your pushrod coming out with the pressure plate? As @kev moose asks can you release the pushrod from the pressure plate? The bearing he refers to is part 14 in the diagram below, the push rod is part 29 and it fits into part 3 which fits into part 14. NB. This diagram is from a Monster 1000 of the same vintage; I know not which parts were used in your conversion but they will be broadly similar. Its easy enough to check if the pushrod bearing is seized, just hold the pushrod and see if you can freely spin the pressure plate - once they're removed from the bike obviously.
If it's leaking through the oil seal behind the pressure plate then, obviously it's an easy and cheap part to replace but if that doesn't work I have heard of people fitting a valve guide seal in there instead, check out this thread on another Ducati forum for more info; https://www.ducati.ms/threads/keep-...al.752620/page-2?post_id=7363938#post-7363938 Also, is the bearing behind the seal OK? again this a cheap part though it can be tricky to remove the old one.
Thanks, guys, for your help. Just a few explanations. During the engine run pushrod is not spinning although I still have the original clutch slave cylinder (pushrod has a hole on the left-hand side but no pin in). Push plate is spinning easily and freely when the pushrod is in the thrust bearing. I can release the pushrod from the pressure plate easily. In the hollow main shaft, I have needle bearing (changed at the last leak, 700 km ago) and seal at the end. Right-hand side of the main shaft is serrated. How sealing between shaft and tightening nuts should be made to prevent oil leakage in case of damaged seal in the main shaft? Later I will upload a picture of my tightening nut and the sealing.
The valve guide seal means totaly new approach, new tightening nut... Can be this long-term solution?
You did fit the seal the correct way round didn't you? Asking because 'a friend' fitted his backwards and it leaked oil into the clutch which (whilst bike stopped) dripped onto the exhaust, causing huge smokescreens when starting up and the clutch to slip for a few miles until it burnt off...
This is my tightening nut with a seal and pushrod. Both seals (nut and hollow main rod) are fitted in the same direction. Thank you for your suggestions and opinions.
It is a lip seal. When engine is running (and clutch disk are off) pushrod is not turning and no oil leak can bee seen.
Sorry to bother you. Regarding my problem and gathering information, I am wondering if my problem maybe comes from inappropriate build-in material-components. Question: in my case I have two lip seals, one (8x16x6mm) nut and other, in the hollow rod (8x12x3mm). Bigger one is made out of VITON (higher temperature resistance up to +170°C), the small one out of NBR (lower temperature resistance up to 100°C). In both cases they can take pressure up to 1 bar (15 PSI). As far as I know oil pressure increase when oil temperature is above 100°C and RMP are 5000 or higher. So far, I didn’t see any other lip seals to be used on push rod and dry clutch. Is this technical solution present at other models with dry clutch? What about the oil pressure? Can oil pump be the issue here? By previous owner info, he changed original (Monster S2R 800) oil pump with 748 oil pump to reduce the oil pressure (with original one he had problem with very high oil pressure-rip off of oil filter)? I am afraid that with seal replacement and with a bit sportier drive (RPM 5000-6000) I will face oil leakage again. Do you know what is a normal level of oil pressure? Is on both lip seal expected higher pressure level? I am considering replacing: - O ring (2x) change on push rod - Lip seal (nut), 8x16x6 mm - Lip seal (main rod), 8x12x6 mm. - Polishing with sandpaper (1500) where lip seal are built-in. I don’t how the sealing between nut and main rod is done. That is open question. How is this usually done? Thank you for you help.
I don’t know what parts were used when the previous owner converted from a wet to a dry clutch but that oil seal around the push rod looks to have too big an internal diameter. Either that or it’s got horrendously worn from the push rod spinning but as you say the rod doesn’t spin with the pressure plate perhaps it’s just the wrong size seal? Is this issue something that’s just happened or has it always been like this since you bought the bike? Have the correct components when doing the dry clutch conversion been used? As a start, if it were me I’d pull the pushrod from the slave cylinder side, replace the 2 o-rings there with new ones. I’d check it’s the correct pushrod too. I’d replace the brown oil seal at the retaining nut which is visible in your photo above with one that has the correct OD, ID and thickness - you’ll need to measure those. However, I hold my hand up and admit I’ve yet to see a dry clutch that has an oil seal around the push rod in the location yours does - hence my question as to what parts were used when the conversion was done. With regards to oil pressures Google will give you the answer.
