| Author | Message | ||
     Vagelis46 |
This is what happened to the worm gears that drive the oil pump. The photo was taken from my 2004 XB12R with 5.500 miles on the clock. I bought the bike brand new 3 months ago. Why it happened? Any suggestions and thoughts? What should I do to prevent it from happening again? The bike is now at the dealer waiting for ... warranty. What should I ask for and demand?  | ||
| Jackbequick |
Failures on the gear have been a not uncommon problem in the past. It appears to result from some slight eccentricity in the gear itself and/or some eccentricity in the shaft it is mounted on. That causes the gear teeth to over mesh causing wear and stress cracks in the hardened steel gear. Eventually the gear teeth chip and break off. Most of the damage seems to happen to the driving gear rather than on the driven gear on the oil pump. Fair amount of info on this in the KV. Buell has a replacement gear made out of a bronze or a similar non ferrous material. That is sold as a racing part IIRC but its use would be appropriate on any Buell. The bronze gear would absorb a little wear and deformation from the accumulated tolerances and eccentricities without developing stress cracks. I'd probably ask the dealer to make sure that the runout on the shaft is not excessive and ask them to replace all damaged parts using the the newer bronze gear instead of the original hardened steel one. If they did not want to pay for the "upgrade" to the better gear, I would offer to pay the difference in the cost to get the better gear. I think it is about a $70 or so part and the stock gear is probably not a lot less. Some people here have said that replacing the steel gear with the bronze, as a matter of routine when doing other work in the cam chest, is a good idea as it will eliminate a potential problem. Jack | ||
| Xldevil |
Since 2006, all XB have the upgraded byrillium-bronze oil pump drive gear. http://www.buell.com/en_us/gear/accessories/Product.asp?Menu_ID=2&ProductLineID=5&CategoryID=1&ProductID=3138 It costs only $49,95. Ralph picture removed at owner's request (Message edited by road_thing on September 21, 2006) | ||
| Vagelis46 |
Is there any data for how long these NEW gears last? How often they should be changed so that nothing breaks up ? Do you think it is a good idea to use a thin engine oil e.g. 5W-40 so that its low viscosity reduces the load and the power input to the oil pump's shaft and therefore the stress on the gears. Will it make a difference in that respect compared to a more viscous oil like 20W-50? (I used so far SYN3 20W-50 and you saw what happened). After watching the gear in my engine a thin oil (even 0W-30)sounds like a good idea. I use the bike for going round roads with many corners and to have the same pace as my friends on Jap bikes I need to rev it between 5000-6500 rpm. This damage, that happened so early(5.500miles), made me wonder if this bike is made for this use, and I made a bad choice buying it. I need all the experience from you guys. Please any tip is welcome. | ||
| Xldevil |
These failures are not related with any oil viscosity.They occur regardless which oil is used,regardless which revs are mostly prefered.(X-engines in Sportsters are more often than not driven in lower revs and they show(ed)OPDG break downs as well)My Sporty showed severe signs of wear after 15K kilometers,my Cyclone after less than 10K kilometers. If you search in the KV for oil pump drive gear,you will find a lot of hypotheses why this gear brakes so often.Until know,no one found the real McCoy. I'm using the updated beryllium-bronce gear for more than 25K kilometers on my Cyclone and another one on my Sportster for more than 15K kilometers.Until know,they show no signs of wear. I'm in close contact with the german Buell community and never heard of any failure so far. Ralph (Message edited by xldevil on September 18, 2006) | ||
| Jackbequick |
I think with the beryllium bronze gear and runout on the shaft within tolerances you'll be okay. That's the same gear they're running on everything up to and including the XBRR's, it seems to be handling the job. I didn't mention it but you dealer should probably also check for damage to the cams, cam gears, and the oil pump that may have been caused by the bits and pieces coming off the gear. The mesh and fit on right angle helical drive gears like that is pretty critical. If the teeth over mesh due to eccentricities and runout on the shaft, and that is what appears to have been happening, it places high spot loads on the gear teeth. The hardness on the steel gears was on the surface and a few thousandths of an inch deep, and it was, by nature, too brittle to handle the stresses that occurred. That probably caused stress cracks and surface damage, gear teeth broke off, and the gears destroyed one another. The beryllium bronze gear is softer than the steel gear and its hardness is the same all the way through. It will deform and wear where it must to accommodate any stresses and it will do that without developing any surface cracks. Any material that flakes off in the process is soft enough that it won't damage the cam gears or anything else in the cam chest. It might be a little early to tell for sure but it looks like the beryllium bronze gear has solved the problems with the gear failures and is also going to provide a good enough service life. If it lasts as long as the rest of the typical XL engine lower end, it should be fine. It will just be another part that is replaced in major rebuilds. You may be using your XB12R a little harder than average if you chase around with a bunch of rice rockets. Can you generally hold your own as far as keeping up with them? And do you like the Buell for what it is? If so, then I don't think you've made a mistake. Many of us consider the preference between the mostly inline four rice rockets and V-twins to be a matter or taste or choice. For us Americans, there is a bit of a national or historical preference too. Jack | ||
| Blake |
We've seen a few failures like that, but none on such young motors. Question: Why would one disassemble the engine of a new bike with only 5500 miles on the odometer instead of take it to the dealer for warranty service? I detect a trollish aroma.  (Message edited by Blake on September 19, 2006) | ||
| Blake |
The answer regardless is that you should receive a full engine rebuild or replacement under warranty. | ||
| Vagelis46 |
Thanks for your answers and info. Everything is clear to me now. Jack, the handling of the XB12R bike is really excellent even for the most experienced and skilled road rider. The corner speed is amazing, especially compared to the Jap supersport standards. If the engine proves reasonably reliable then I will be proud to say that I own an American Motorcycle and buy the new Buell when it gets released. It is really a shame for a bike like this to get bad reputation from silly problems like the oil pump gears. In my opinion to really solve the problem, Buell should reject the worm gear design and install a set of bevel gears or a chain to drive the oil pump. As I was taught at the University worm gears are unsuitable for high revving applications and unless Buell rejects them, there is really no cure. Blake, the photo was taken at the dealer's workshop. I should be receiving the new engine the next 2 weeks. I will tell them to check whether the new bronze gear is installed in the new engine and hope that it will not fail after 5.500 miles. Ralph, as far as oil is concerned this time I will use a fully synthetic 5W-40 e.g. Shell Ultra. It might help. We will see. | ||
| Jackbequick |
I'm glad to hear that you are holding your own with the rice rockets and like the Buell. And it is also good that your dealer and Buell are standing behind the warranty. I think many owners like the bike for its traditional and unique traits. It is not a bike I would recommend to someone looking for the most power and speed, state of the art technology, high reliability, and low maintenance. The Buell (XL) engine design unitized the separate engine and transmission of an older design. The oil pump was in the space the transmission was moved to, and the design of the new oil pump drive made some sacrifices to fit the space available without making the engine wider. The design has been in use for about 50 years without too many problems, hopefully this is a problem solved now. The happiest Buell owners are people that accept and like the somewhat dated technology and many prefer to do all their own work. Those kind of owners probably would have read about the gear problems and may caught that before the failure. Several people here that removed their oil pump, inspected their gears, and saw the problem developing before it caused the failure. The failures seemed to take place between 5,000 and 15,000 miles or so, there are some details about it in the KV. I had a 2000 Buell M2 for about 4,000 miles (2,000 to 6,000 on the odometer) and inspected the gear before I sold it. It was wearing normally and I left it in place. The new gear was well received by those who were aware of the possible problem. Some changed to the new gear simply because it looked like a better idea. I doubt that the 20W-50 oil contributed to the failure. If that oil was appropriate for the seasonal temperatures you are riding in, I would not change it for a lighter weight oil to reduce the load on the oil pump. That engine known to run anywhere from very warm to very hot in warmer weather because it is air cooled. You also say you often ride at higher engine speeds and that increases the demands on the lubrication system. I think it would be better to stay with an oil that was rated for your temperatures or even warmer temps rather than for cooler temps. Jack | ||
| Blake |
the photo was taken at the dealer's workshop. I should be receiving the new engine the next 2 weeks. Excellent! Thanks for vanquishing the eau de'troll suspicions.  I agree that the oil pump drive configuration should be rethought. The reduction ratio required is what would seem to have led the engineers to use the worm type drive. I believe that there may be other more durable worm drive configurations, especially for the driven gear that would greatly reduce wear stresses and contact pressures. | ||
| Road_thing |
 Here's a pic of the new gear, from the Buell web site. rt | ||
| Reepicheep |
Sorry to hear about your gear. I have the gear from my old Cyclone right here on my desk at work, I got it before it went. I am close to 15k on the 05-9sx now, sounds like I should drop the oil pump and do a visual inspection this winter. I had hoped the XB's did not have the problem, and it seems a lot better then the tubers were, but the fact that Buell used the new part in 06 says something, and now you have a real data point. If you switch oil, you may find yourself burning it like crazy. I tried Castrol 5w50 full synthetic for a while, and while it worked well, it dissapeared *really* quickly. Going back to real 20w50, and my oil consumption "problems" went away. I'd love to see one of those new material gears after a 30,000 hard miles (or a season of racing) to see how they wear relative to a new gear. Dropping the oil pump to inspect the gear in place is a really easy job, at least on the Cyclone. I'm guessing it will be easy on the XB also. | ||
| Tleighbell |
Does this mean we should all be replacing the gear asap? How much work is it? Is there a way to see if you are having a problem such as oil analysis or checking the swarf on the drain plug? Also, should we all be re-torquing our crank pinions to the new specs? | ||
| Reepicheep |
I think most of the crank nut torques were right from the factory, they were just wrong in the manual. So unless you removed and replaced, you were probably fine. Inspection of the oil pump drive gear is easy, replacement is hard (remove both rocker boxes), but waiting for it to fail is *really* hard (trashed engine). I'll be inspecting mine on the new 9sx this winter (15k miles). | ||
| Tleighbell |
How do you inspect? just pull off the cover? How do you know if you have problems other than seeing cracked teeth? My bike is still under warranty. Will warranty cover it? | ||
| Jackbequick |
No, you drop the oil pump out from below the cover. Then you can look up in there with a mirror and flashlight to inspect the gear. I think there is a good description of this in some earlier threads in the KV. Jack |
