Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
|
techtalk:evo:oil03 [2019/08/05 11:34] ixl2relax [Sub-Documents] |
techtalk:evo:oil03 [2019/08/05 12:43] ixl2relax [Known Drive Gear Failure] |
||
|---|---|---|---|
| Line 241: | Line 241: | ||
| **Inspect your oil pump drive gear** especially if you've gotten your gearcase cover off anyway to hopefully prevent gear failure before it happens. \\ | **Inspect your oil pump drive gear** especially if you've gotten your gearcase cover off anyway to hopefully prevent gear failure before it happens. \\ | ||
| - | * This is a common failure in Sportsters, even when nothing gets into the pump to lock it up first. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1848987)) The teeth get sharp and then they break off. \\ If something gets into the pump and locks it up, the teeth get ripped off the gear. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1974986&highlight=bronze+drive+gear&page=3)) | + | * Generally speaking, the stock (drive gear) is fine for stock power levels and rpm's. Sure, there are some failures on stock or near stock bikes, but it's pretty rare. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool&page=2)) Of course, they do eventually wear down and should be replaced with the upgraded version. |
| + | * The OEM gear is hardened on the surface, but once that is worn through it will wear extremely fast. ((Scuba10jdl http://xlforum.net/forums/showthread.php?t=2002257&highlight=pinion+gear+part+number)) | ||
| + | * This is a common failure in [high HP or RPM] Sportsters, even when nothing gets into the pump to lock it up first. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1848987)) The teeth get sharp and then they break off. \\ If something gets into the pump and locks it up, the teeth get ripped off the gear. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1974986&highlight=bronze+drive+gear&page=3)) | ||
| * The failure happens because of pinion shaft runout which causes the engagement depth of the teeth to change as the pinion shaft rotates. \\ What happens is the gear will wear badly in one area. You'll see the teeth getting real sharp there. 180 degrees from that spot, the gear will look like new. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool&page=2)) | * The failure happens because of pinion shaft runout which causes the engagement depth of the teeth to change as the pinion shaft rotates. \\ What happens is the gear will wear badly in one area. You'll see the teeth getting real sharp there. 180 degrees from that spot, the gear will look like new. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool&page=2)) | ||
| * So lots of people get fooled when they check the gear. They'll look at the visible portion from their vantage point only. \\ You have to look all the way around the gear though. The wear will be isolated to one area only. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool&page=2)) | * So lots of people get fooled when they check the gear. They'll look at the visible portion from their vantage point only. \\ You have to look all the way around the gear though. The wear will be isolated to one area only. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool&page=2)) | ||
| Line 271: | Line 273: | ||
| * This upgrade is compatible with 1991-later models. | * This upgrade is compatible with 1991-later models. | ||
| - | * HD finally came out with an upgraded drive gear in 2006 for the Buell models to solve the high-rpm wear problem. But they never bothered to put it in XL's. It probably costs more than the steel gear, and given that failures are rare at 60hp, it just wasn't needed. But if you're hopping up an XL, it's a good piece of insurance. Especially if you're going into the cam box for a cam swap anyway, then it's a no-brainer in my opinion. It's a really ugly failure that generally requires a full tear down to fix. The gear is an ounce of prevention. ((aswracing http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool&page=2)) | + | * HD finally came out with an upgraded drive gear in 2006 for the Buell models to solve the high-rpm wear problem. Pinion shaft runout was the cause and occurs mostly because of high rpm operation causing flywheel spread. This failure has always been a terrible issue with Buells as they had higher rev limits from the factory - 6800 for most tubers and up to 7500 for the XB9. Even bone stock Buells were having this failure. |
| + | * But the MoCo never bothered to put it in XL's. It probably costs more than the steel gear, and given that failures are rare at 60hp, it just wasn't needed. But if you're hopping up an XL, it's a good piece of insurance. Especially if you're going into the cam box for a cam swap anyway, then it's a no-brainer in my opinion. It's a really ugly failure that generally requires a full tear down to fix. The gear is an ounce of prevention. ((aswracing http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool&page=2)) | ||
| * The bronze gear doesn't have this issue because of the different wear characteristics of the metal. The oil pump drive gear sees a lot of sliding friction, which causes the steel on steel to wear quickly. Bronze has much less friction than the OEM gear. The bronze gear is also uniform throughout, and thus it wears more predictably. So even if bronze is softer than steel, all of the factors in this application end up giving it a longer life than the steel gear. ((Scuba10jdl of the XLFORUM http://xlforum.net/forums/showthread.php?t=2002257&highlight=pinion+locking+tool)) | * The bronze gear doesn't have this issue because of the different wear characteristics of the metal. The oil pump drive gear sees a lot of sliding friction, which causes the steel on steel to wear quickly. Bronze has much less friction than the OEM gear. The bronze gear is also uniform throughout, and thus it wears more predictably. So even if bronze is softer than steel, all of the factors in this application end up giving it a longer life than the steel gear. ((Scuba10jdl of the XLFORUM http://xlforum.net/forums/showthread.php?t=2002257&highlight=pinion+locking+tool)) | ||
| * It's cheap insurance, even if you only plan to visit 7,000 RPM instead of living there. ((Centennial Sportster http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool)) | * It's cheap insurance, even if you only plan to visit 7,000 RPM instead of living there. ((Centennial Sportster http://xlforum.net/forums/showthread.php?t=1920827&highlight=pinion+gear+locking+tool)) | ||
