cash1000 Posted July 3, 2023 Share Posted July 3, 2023 Has anyone else used Penrite gearoil in their gear box? GEAR OIL 80W-90 (Mineral) | Penrite Oil By process of elimination I think it is causing oil to mist over the back of my RM's gear box and the clutch to slip. Clutch slip goes away once I've travelled 20 odd k's. Going to change back to Spectro oil I was using before. Motorcycle Hypoid Gear Lubricant - Spectro Performance Oils (spectro-oils.com) I would use redline but no one local supplies it. Link to comment Share on other sites More sharing options...
docc Posted July 3, 2023 Share Posted July 3, 2023 The only way any Gearbox oil would cause your (dry) clutch to slip would be a leak, no matter what oil is in the box . . . You have been all back and forth through this, though, haven't you @cash1000 ? 4 Link to comment Share on other sites More sharing options...
cash1000 Posted July 3, 2023 Author Share Posted July 3, 2023 Misting over Gear box was happening before the gearbox saga (Link ? don't go there) I've read somewhere on here of some gearbox oils causing gearbox leaks. I had also noticed the Penrite oil had reduced in thickness from what I had used before. So I put 2 & 2 together. Yes a leak or mist could be reason clutch is slipping. So theory is replace oil to one I've used before with no problems. If problems still occur where to from there ...... Link to comment Share on other sites More sharing options...
MartyNZ Posted July 3, 2023 Share Posted July 3, 2023 I have Penrite Pro Gear 75W-90 in my gearbox. No oil mist. The troublesome vent hose can split at the outlet on top of the bell housing, which lets oil vapor into the clutch area. When I bought my bike, it came with an oil drip at the witness hole at the bottom of the bell housing. Replacing the vent hose fixed the leak, but I couldn't see the cracks in the hose until I took it out. I have a part used bottle of Shockproof Heavy with about 750ml still in it, not quite enough for a gearbox. I bought it from Brake n Transmissions BNT 2 Link to comment Share on other sites More sharing options...
audiomick Posted July 3, 2023 Share Posted July 3, 2023 7 hours ago, docc said: The only way any Gearbox oil would cause your (dry) clutch to slip would be a leak, no matter what oil is in the box . . . I would have to agree completely with that. Link to comment Share on other sites More sharing options...
gstallons Posted July 3, 2023 Share Posted July 3, 2023 cash , IF there was oil getting into your clutch area and causing clutch slippage , this would not go away after a few kms. Petroleum products on a clutch will stay on a clutch . Can you explain this slippage and how bad , how long it has been going on & how long this occurs . 3 Link to comment Share on other sites More sharing options...
80CX100 Posted July 3, 2023 Share Posted July 3, 2023 Idk what all the fine differences are between the Spine frame 6 spd and Tonti 5 spd set ups;but I've cured a slipping clutch issue with the paint thinner rinse bodge. Shortly after I got my new to me 2008 CalVin, I noticed the clutch slipping when I really pushed it hard in higher gears. A PO had overfilled the tranny;probably just dumped in a full litre bottle of gear oil. Dumped the oil,put in the right amount,then rinsed the clutch plates a couple of times with paint thinner (Lots of info out there on methods). Clutch has worked fine ever since. fwiw 2 Link to comment Share on other sites More sharing options...
audiomick Posted July 3, 2023 Share Posted July 3, 2023 5 hours ago, 80CX100 said: ..rinsed the clutch plates a couple of times with paint thinner... I've read here and there that brake cleaner will do it too, but I've never tried it. On the assumption that the clutch plate is otherwise junk, one could give it a go. Link to comment Share on other sites More sharing options...
cash1000 Posted July 4, 2023 Author Share Posted July 4, 2023 23 hours ago, MartyNZ said: I have Penrite Pro Gear 75W-90 in my gearbox. No oil mist. The troublesome vent hose can split at the outlet on top of the bell housing, which lets oil vapor into the clutch area. When I bought my bike, it came with an oil drip at the witness hole at the bottom of the bell housing. Replacing the vent hose fixed the leak, but I couldn't see the cracks in the hose until I took it out. I have a part used bottle of Shockproof Heavy with about 750ml still in it, not quite enough for a gearbox. I bought it from Brake n Transmissions BNT Area around vent hose looks dry but from what you say it could be the cause of both problems. Think I will go with oil I know 2 Link to comment Share on other sites More sharing options...
cash1000 Posted July 4, 2023 Author Share Posted July 4, 2023 16 hours ago, gstallons said: cash , IF there was oil getting into your clutch area and causing clutch slippage , this would not go away after a few kms. Petroleum products on a clutch will stay on a clutch . Can you explain this slippage and how bad , how long it has been going on & how long this occurs . Release clutch lever revs build without going forward then you get forward motion rather than straight away. This occurs standing still or moving. This lessens the further you go. i.e trip into town is 40ks through country roads and built up areas. Slipping stopped after about 20ks and didn't at all coming back home. Link to comment Share on other sites More sharing options...
pete roper Posted July 4, 2023 Share Posted July 4, 2023 On 7/3/2023 at 11:15 AM, cash1000 said: Has anyone else used Penrite gearoil in their gear box? GEAR OIL 80W-90 (Mineral) | Penrite Oil By process of elimination I think it is causing oil to mist over the back of my RM's gear box and the clutch to slip. Clutch slip goes away once I've travelled 20 odd k's. Going to change back to Spectro oil I was using before. Motorcycle Hypoid Gear Lubricant - Spectro Performance Oils (spectro-oils.com) I would use redline but no one local supplies it. I've used Penrite pretty much exclusively for thirty years. If your clutch is slipping it's not the choice of oil. There are a host of possible causes but the oil type isn't one of them. 5 Link to comment Share on other sites More sharing options...
gstallons Posted July 4, 2023 Share Posted July 4, 2023 cash do this , # 1 start your bike and allow it to warm up as you normally do. # 2 pull your clutch lever all the way in and release the lever 10 Xs in a row # 3 put the bike in gear and take off as normal # 4 did you notice ANY difference ? # 5 after you get going for a while, get your bike in 3rd gear and go as slow as possible and roll on the throttle . Does the clutch slip when you do this ? # 6 do the clutch pull test again 10 Xs after the bike is completely warmed up after you get through with your ride. Did you notice ANY difference in the before and after ? 2 Link to comment Share on other sites More sharing options...
cash1000 Posted July 5, 2023 Author Share Posted July 5, 2023 21 hours ago, pete roper said: I've used Penrite pretty much exclusively for thirty years. If your clutch is slipping it's not the choice of oil. There are a host of possible causes but the oil type isn't one of them. Thanks Pete. Me grasping at straws. Link to comment Share on other sites More sharing options...
80CX100 Posted July 5, 2023 Share Posted July 5, 2023 It sounds like the issue is relatively minor,if simply warming it up & riding it for a while cures it. Is it because air in the line is expanding, giving you fuller motion on the clutch push rod and bleeding might cure it? Is it because surface contamination on the clutch plates is scuffed/burnt off with use & a rinse might cure it? Combination of both or something else completely? gstallons post reminded me of some of the finer details of my slipping clutch cure. After I had done a couple of paint thinner rinses, I took it for a test ride;it was still slipping a little. While the clutch plates were wet from the solvent,I found a quiet back road, and in lower gears, ie,2,3 as I gently rolled on the throttle,I rapidly fanned the clutch many times, 10-15,literally abusing the clutch as much as I could;I repeated that clutch abuse 3-4 more times. That apparently scuffed & cleaned up the surface of the clutch plates enough to cure the problem;it hasn't slipped since. fwiw ymmv 1 Link to comment Share on other sites More sharing options...
gstallons Posted July 7, 2023 Share Posted July 7, 2023 On 7/4/2023 at 11:16 PM, cash1000 said: Thanks Pete. Me grasping at straws. Don't grab at straws , do methodical evaluations and testing. 2 Link to comment Share on other sites More sharing options...
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