Want to bring to light an issue I am having with the 300 series three-bladed Whirlwind composite prop on my RV14: Scoring of the hub from the rubber gaskets. Bottom line, so far its a Cluster F and I am not sure how it will resolve.
Background Info:
RV14 with IO-390 Thunderbolt - about 620 hours TTAF and prop. I finished the plane and first flight was in late 2020. Other than this issue - I have loved the prop. Looks great and performs great (top speed 191 knots, ROC +/-2000'/min.

Initial Issue
At about 570 hours the prop started spitting grease on the windscreen. Not a lot, but in about a 3 hour flight it would leave a lot of specks on the windscreen.

Finally, about 30 hours later (after consulting with Whirlwind during this time) I sent it in to JDW props in Ohio - a well regarded service center according to Whirlwind and others - for a rebuild. Was supposed to be pretty straight-forward, and would take about 1-2 weeks and run about $1-2K all in unless there was something unusual.
A Bit More Detail
Coming up on seven weeks now with no firm resolution in sight. JDW has been quasi-ghosting me - its been very difficult to get updates from them, and they have not been forthcoming with whom I can contact at Hartzell for more info (now that Hartzell owns Whirlwind and Whirlwind has shut down its San Diego offices and apparently moved in with Hartzell in Ohio). According to JDW, Hartzell now has my hub. What I do know is that the rubber O-rings on the hub have apparently scored the hub (see photo below) and this is the root issue of the grease leakage - this is apparently an issue that cropped up in the early production models on the 300 series and a couple other models (that, at least is what I was told JDW).

Yes, those grooves above were scored into the aluminum hub by the rubber gasket.
That said, early this year when I inspected my prop as part of my annual, Whirlwind told me that the slight leakage I had seen (only inside the nose cone around the interface of the hub with each blade - see pics) was most likely due to the 'old' spec grease that was used on my early production model, and that this had been addressed with the new spec grease. They didn't mention the 'scoring issue' at all. I was not aware of a 'scoring issue' until JDW had the prop and had disassembled it as part of the inspection/rebuild process.


The two pics above are from my last annual when I initially noticed the grease leakage in the nose cone.
JDW told me Whirlwind has known about the scoring issue and had developed a fix that involved sleeving the aluminum hub with a steel sleeve - I suppose the idea is that the rubber gasket would not score the steel as it did the aluminum. So, JDW has apparently sent my hub to Hartzell to have this done. At this point, I can't seem to find out how long this will take, let alone whether Hartzell or me will be footing the bill. I've been trying to get a direct contact at Hartzell, but to no avail.
As I know more I will update this thread.
Background Info:
RV14 with IO-390 Thunderbolt - about 620 hours TTAF and prop. I finished the plane and first flight was in late 2020. Other than this issue - I have loved the prop. Looks great and performs great (top speed 191 knots, ROC +/-2000'/min.

Initial Issue
At about 570 hours the prop started spitting grease on the windscreen. Not a lot, but in about a 3 hour flight it would leave a lot of specks on the windscreen.

Finally, about 30 hours later (after consulting with Whirlwind during this time) I sent it in to JDW props in Ohio - a well regarded service center according to Whirlwind and others - for a rebuild. Was supposed to be pretty straight-forward, and would take about 1-2 weeks and run about $1-2K all in unless there was something unusual.
A Bit More Detail
Coming up on seven weeks now with no firm resolution in sight. JDW has been quasi-ghosting me - its been very difficult to get updates from them, and they have not been forthcoming with whom I can contact at Hartzell for more info (now that Hartzell owns Whirlwind and Whirlwind has shut down its San Diego offices and apparently moved in with Hartzell in Ohio). According to JDW, Hartzell now has my hub. What I do know is that the rubber O-rings on the hub have apparently scored the hub (see photo below) and this is the root issue of the grease leakage - this is apparently an issue that cropped up in the early production models on the 300 series and a couple other models (that, at least is what I was told JDW).

Yes, those grooves above were scored into the aluminum hub by the rubber gasket.
That said, early this year when I inspected my prop as part of my annual, Whirlwind told me that the slight leakage I had seen (only inside the nose cone around the interface of the hub with each blade - see pics) was most likely due to the 'old' spec grease that was used on my early production model, and that this had been addressed with the new spec grease. They didn't mention the 'scoring issue' at all. I was not aware of a 'scoring issue' until JDW had the prop and had disassembled it as part of the inspection/rebuild process.


The two pics above are from my last annual when I initially noticed the grease leakage in the nose cone.
JDW told me Whirlwind has known about the scoring issue and had developed a fix that involved sleeving the aluminum hub with a steel sleeve - I suppose the idea is that the rubber gasket would not score the steel as it did the aluminum. So, JDW has apparently sent my hub to Hartzell to have this done. At this point, I can't seem to find out how long this will take, let alone whether Hartzell or me will be footing the bill. I've been trying to get a direct contact at Hartzell, but to no avail.
As I know more I will update this thread.
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