You could always pull the oil pump out and inspect it from that angle. The oil pump is only held to the motor with a pair of torx screws. Be sure to rotate the crank over so you can fully inspect the gear, as it can wear unevenly. If it fails, you will have a paperweight of a motor.Originally Posted by XB12Steve
I have the interest in learning if you have the time to teach me. Like I said, I'm not particularly worried about my current oil pump, it's more my curiosity as to what it would take to accomplish it. I agree with you and Cooter in that it probably wouldn't be worth it, but if everything I did as a gear head had to make sense to other people it would make for a pretty boring hobby.
You will need a RH case for starters, all the obvious oil pump parts and covers, new cams, and a new wire harness and ECM. I think the oil hoses are no longer available, but a hose shop should be able to make up a set.
So what all has to come off to do drive gear? Rocker box cover then rockers? Can push rod tubes stay in place?
The only thing that really surprises me out of that is the harness and ECM. What triggers that? It's a shame about the case half, I was hoping they had not changed it, but I can see why they would.
Oil Pump Drive Gear--Oil Pump Driven Gear stats and answers:
The Driven gear is mounted to the oil pump itself...The Driving gear is under the cam cover. Identical layout for all tube frame Buells and 2003-2007 inclusive all XB models.
Factory and dealership records of failures are spotty at best, but "on average"...10% of Tube-framed Buells suffered driven gear failure...5% of XB's suffered driven gear failure. The XB has the oil pump mounted slightly differently than Tuber models, hence the significantly lower failure rate. 2008 to end of production ALL XB's have a completely different system to drive the pump unit for oil circulation and pressure.
Replacement Driven gear is H-D part # 26391-06 and is a beryllium bronze alloy, developed by Bill Werner of H-D racing fame for the XR750 program...then transferred to XL models for Battle of the Twins racing.
Pic shows Driver gear....Driven gear on end of pump shaft and shown in SM "oiling" section.
NOTE: the rampant gear failure internet hysteria from the past decade consistently failed to mention the one common denominator, which was owner/operator induced failure.
How? Three simple faults directly attributable to ownership:
1-Constantly bouncing the motor off the rev-limiter which had a propensity to cause pump cavitation
2-Incorrect oil viscosity (read too thick) used for cold weather riding conditions
3-Failure to allow the motor to come up to operating temp before loading the motor with heavy throttle demands and high revs.
#3 was most always the culprit.
buell XB case.jpg
Last edited by Barrett; 08-03-2021 at 05:12 PM.
Thanks for the clarification man. This helps a lot. I'm not guilty of any of these but the previous owner(s), who knows?
Are there any dead giveaways prior to this happening? I'd think metal showing up in oil changes would be one; not the case in my bike. Any odd noises coming from that side?
^^^^^^^^^^^^^^^^^
My pleasure. With fully functional known good oil pressure sending unit...good wire connection to same...oiling system filled to max capacity....known good quality filter installed and correct viscosity oil being used....the first and foremost tell-tale sign of a failing Driven gear is a flickering oil pressure dash mounted light at warm idle speed of 1000rpm.
We need to add this to a STICKY. Seriously, this is good stuff to know.
Thanks again Barrett.
The case half is needed for the crank trigger, since the cam sensor is eliminated. You also need it so you don’t have a big hole where the oil pump “snout” sticks through to engage the gear on the crank pinion shaft.
The crank sensor triggers from raised spots on the flywheel, which the ecm uses to fire the coil. The firing pattern is much different from CPS to the CKP, so the new ECM is needed. Since the new ECM (DDFI-3) has many more pins that the old one (DDFI-2), your plugs won’t work. And if you are in the middle of the plunge it’s probably easier to replace the harness than mod it.
There will likely be someone with advanced DDFI skills and knowledge who may be able to make the DDFI-2 ECM and harness work with the CKP, but now we’re really going down the rabbit hole.
My suggestion is to stick with the 2007 pump and bronze gear. The oil pump was redesigned at that point and was used on the Sportster ‘til the end. They never did use the bronze gear, though.
Hammer performance has a YouTube video where they show the difference in the oil pumps, and if you dig around the World Wide Web long enough you’ll probably find the Harley tech sheet that shows the difference between the two.
7AB97CF9-6657-44F0-A73C-D281E6176099.jpeg
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