KHyde Posted October 13 Report Posted October 13 Prop was last overhauled in 2004. Resealed in 2011. It’s got about 1200 hours on it. When we bought it a couple of years ago it had some grease that would sling out on the prop (3 inches or so). I’m new to GA aircraft and was advised it wasn’t a big deal. I’ve asked a few mechanics about it every now and then and they’ve always said we cleaned it off really well. Just keep an eye on it (bad if there’s more leaking and bad if it stops leaking). When I mentioned it to Savvy they said if McCauley is leaking moisture can get inside and corrosion can develop and not to ignore it forever. It just came out of annual today and I didn’t notice any grease on the prop after flight, but it doesn’t seem to leak every flight. I’d love some advice on overhaul vs. keep waiting vs. top prop conversion.
Yetti Posted October 13 Report Posted October 13 tell us the plane or the prop. Unless you are getting prop grease on the windscreen. Not to worry. Also there was a problem with Aeroshell 6 grease. use Aeroshell 5 instead.
MikeOH Posted October 13 Report Posted October 13 I’ve had the same issue since I’ve owned my F. I have a Hartzell 2 blade with the non-AD hub. I had the prop overhauled and it still leaked! Sent it back…still leaked! Flew for a few years and sent it in again…guess what? Yup, still leaks! But, now only one blade, and it’s less. I’ve pretty much resigned myself to just living with it 2 1 1
KHyde Posted October 13 Author Report Posted October 13 1 hour ago, Yetti said: tell us the plane or the prop. Unless you are getting prop grease on the windscreen. Not to worry. Also there was a problem with Aeroshell 6 grease. use Aeroshell 5 instead. It’s on the prop. Definitely not on the windscreen.
KHyde Posted October 13 Author Report Posted October 13 1 hour ago, MikeOH said: I’ve had the same issue since I’ve owned my F. I have a Hartzell 2 blade with the non-AD hub. I had the prop overhauled and it still leaked! Sent it back…still leaked! Flew for a few years and sent it in again…guess what? Yup, still leaks! But, now only one blade, and it’s less. I’ve pretty much resigned myself to just living with it Well dang. I’ve heard similar from a friend on the field. Once I realized how many years it had been since overhaul it got me a little rattled, but I guess it’s somewhat common.
PT20J Posted October 13 Report Posted October 13 The McCauley manual says to cycle the prop all the way to the low speed/ high pitch stop a few times. I did this and it stopped my minor leaks. 3 2
takair Posted October 13 Report Posted October 13 I have come to the opinion that if you service the prop every annual, it eventually gets full (12 years or less if over serviced) and further grease needs a way out. Seems to coincide with recommended OH time. So, full hub….some migrates out the seal. The risk of not servicing is corrosion in the hub and/or dried grease. So, it’s possible you simply have a slightly over serviced hub. The grease breaks down and the oil seeps out. As Yetti said, Arroshell grease got worse over time and is no longer the preferred grease after overhaul. 1
MikeOH Posted October 13 Report Posted October 13 Mine was overhauled around the time of the Aeroshell issue. But it leaked before and after, so who knows? I think Nyco is the new recommendation, but can’t be mixed with the Aeroshell. However, you can mix Aeroshell 5 with 6, FWIW.
carusoam Posted October 13 Report Posted October 13 Fresh out of annual? Fresh grease gets pushed into the hub causing some to escape out the seals… deep cycling the prop? another reason some grease may get past a seal that has been sitting awhile… when grease comes out three inches of prop blade… it will leave small bits of grease on the windscreen… a clean windscreen is required to see it… let’s invite… @Cody Stallings for some insight on prop grease leaking… Best regards, -a-
PT20J Posted October 14 Report Posted October 14 The OP said he has a McCauley prop. Those get greased only when taken apart. There are no external grease points like a Hartzell prop. 2 2
Cody Stallings Posted October 21 Report Posted October 21 On 10/13/2025 at 6:23 PM, carusoam said: Fresh out of annual? Fresh grease gets pushed into the hub causing some to escape out the seals… deep cycling the prop? another reason some grease may get past a seal that has been sitting awhile… when grease comes out three inches of prop blade… it will leave small bits of grease on the windscreen… a clean windscreen is required to see it… let’s invite… @Cody Stallings for some insight on prop grease leaking… Best regards, -a- Sounds like the blade Orings have just given up the fight, a reseal would fix him up. 1
MikeOH Posted October 21 Report Posted October 21 52 minutes ago, Cody Stallings said: Sounds like the blade Orings have just given up the fight, a reseal would fix him up. @Cody Stallings I'm sure the O-rings were replaced when mine was overhauled, and then when I sent it back. What would be a possible reason it still leaks??
Sue Bon Posted October 21 Report Posted October 21 On 10/13/2025 at 10:47 PM, Yetti said: Unless you are getting prop grease on the windscreen. Not to worry. I have this. My prop will be sent in for the six-year overhaul in January. I have an MT propeller. Can I still fly 10-15 hours before January? 1
Yetti Posted October 21 Report Posted October 21 9 hours ago, Sue Bon said: I have this. My prop will be sent in for the six-year overhaul in January. I have an MT propeller. Can I still fly 10-15 hours before January? I would ask your mechanic. But that is what mine usually tells me. Just some seepage on the blades is not that much of an issue. 3
Slick Nick Posted October 22 Report Posted October 22 On 10/20/2025 at 8:20 PM, MikeOH said: @Cody Stallings I'm sure the O-rings were replaced when mine was overhauled, and then when I sent it back. What would be a possible reason it still leaks?? Your bearings are toast. The best and newest o rings in the world can't seal against excessive play in the blades due to worn bearings.
MikeOH Posted October 22 Report Posted October 22 5 hours ago, Slick Nick said: Your bearings are toast. The best and newest o rings in the world can't seal against excessive play in the blades due to worn bearings. While I can't rule that out, it doesn't seem too plausible as the prop was OVERHAULED. Additionally, I cannot detect ANY play when I attempt to push, pull, or twist the blades. If the bearings were worn that badly, I'd think there would be some movement.
PT20J Posted October 22 Report Posted October 22 52 minutes ago, MikeOH said: While I can't rule that out, it doesn't seem too plausible as the prop was OVERHAULED. Additionally, I cannot detect ANY play when I attempt to push, pull, or twist the blades. If the bearings were worn that badly, I'd think there would be some movement. Try deep cycling the prop all the way to the high pitch stop a few times. That worked for my McCauley. Couldn’t hurt to try on your Hartzell. 1
Slick Nick Posted October 23 Report Posted October 23 4 hours ago, MikeOH said: While I can't rule that out, it doesn't seem too plausible as the prop was OVERHAULED. Additionally, I cannot detect ANY play when I attempt to push, pull, or twist the blades. If the bearings were worn that badly, I'd think there would be some movement. Yeah, well, in 2024, my prop was OVERHAULED too, and started pissing oil only 150 hours later. Had a different shop rebuild it, and the bearings were shot. The spec on those bearings is pretty tight. At overhaul time, they are a go/no go item. They can be right on the cusp of being toast, and the prop shop can still reuse them and legally call it an overhaul unless you’ve specified new bearings, or they take the onus to change them. It doesn’t take long once the blades are allowed to move in the thrust direction. Within 50 hours of the first symptoms, I was getting splatter on the windshield. My blades had no tangible play in them when I checked, but the prop shop said they were way beyond spec. If you are able to feel play, the hub itself is probably buggered. Cost me $650 and 3 days to have the prop rebuilt with new bearings and seals. Hasn’t leaked a drop since. The moral of the story is, just because a prop has been overhauled, doesn’t mean jack. Especially here in Canada where we have the mandatory 10 year overhaul rule, regardless if the blades have turned or not. 1
MikeOH Posted October 23 Report Posted October 23 3 hours ago, PT20J said: Try deep cycling the prop all the way to the high pitch stop a few times. That worked for my McCauley. Couldn’t hurt to try on your Hartzell. Thanks! I actually saw you posted that recently and I did just that on runup before my last flight. I did NOT notice any grease after I got back...maybe too soon to tell, but fingers crossed! For whatever reason, deep cycling a prop is not something I've ever been 'comfortable' doing, but I did this time! 1
SilentT Posted October 24 Report Posted October 24 Wow my prop is coming off right now because I picked it up monday and flew from sandpoint to flying cloud then to Peoria IL. Every stop had oil on 50% of the blade. its only got 80 hours but its almost 20 years old age wise. Soooo its going monday to get resealed. If it leaks after that... F*it 2blade MC whats this about oil choice, its an A36D, what should i be using?
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