Prop OH needed?

[Shadrach]

Hi Folks,

The HC-2Y prop on our F model recently started shedding a little grease. I cleaned it up and it seamed to be an isolated incident as the face of the prop remained clean after a 3hr xcountry. It has been 10 years and about 700hrs since overhaul. The airplane is always hangared and the prop has passed it's EC insp every 100hrs without issue.  I decided to call my trusted prop shop and ask about an IRAN/reseal as the .  I was surprised when I was told that an overhaul was the only option they would offer.  I was told that they would only perform maintenance IAW the manufacturer's recommended time intervals or sooner.  This seems to be a new policy, though when I asked they said that that has always been the case.  OH is $1800, which is reasonable but I really don't want the blades ground unless there's a compelling reason.  I asked for a compelling reason and was told that grinding "relieves" the stress on the blades.   I look forward to your feedback!

[KSMooniac]

Time for a new shop!

Sent from my iPad using Tapatalk

[Shadrach]

Just now, bluehighwayflyer said:

Hi, Ross.  I would fly it for a while longer and see if the leak returns.  If it does, unless you are willing to take a chance that they will sand one or both of the blade hubs down .001" under spec and then declare it or them to be unairworthy, I would try another prop shop.  This happened to us once back in the early 90s I believe it was and now I am very leery of prop overhauls.  Good luck!  I'm looking forward to hearing how this unfolds for you.

Jim   

This is my plan. The funny thing is that when they OH'd in 06, they said it had enough blade material for 2 more overhauls.

[geoffb]

I just recently started getting a little tiny bit of grease from mine, on a 2005 overhaul.  Cleaned it up and determined it's coming out of the zirk fittings.  Just a couple drops but makes a nice streak on the blade.  Hopefully you find someone to make it stop without doing a full overhaul.

[Shadrach]

Just now, bluehighwayflyer said:

Is there any chance that it is oil from inside the cowling and not grease from the prop that you are seeing, Ross?  I only ask because you said that it seems to have stopped on it's own and we all know that airplanes and cars rarely fix themselves.  Maybe you were a little sloppy during your most recent oil change and now there is some spilled oil blowing out of the cowling?  I have done just this a few times and it manifests a lot like a prop leak. 

Fingers crossed ...

Negative. I was hoping the same thing, but after further investigation, I could easily trace the the grease stain from the bases of the shank at the hub.  It is not uncommon for a glob of grease to work past a seal on occasion in between reseals/overhauls.

[Hank]

Aluminum does not "stress relieve" from grinding. But then, I mainly grind steel at work, not aluminum. But I would expect the grinder to have a steady flow of coolant to minimize twist and warpage, so there's no heat to relieve any stress. Copper work hardens and can be stress relieved with heat, though.

A pertinent question to them would be, "how does grinding the face of the blades affect a bad rubber seal at the bottom? All I have is a leak." On the other hand, the best answer is probably to go somewhere else, then let them know why you aren't coming back after the job is completed. If they want, cover the shop's identification and send them a copy of the invoice showing the work done.

Not many things I despise more than a rat bast@rd!

[N601RX]

I think the outer skin of the aluminum work hardens over time from the continual flexing of the prop.  They grind the top layer away leaving a new soft layer on the outside. Assuming no deep nicks or corrosion this should be a function of flight hours and not calander time.

This process seems to be more of an art than science.  They take a disc sander and make long strokes back and fourth on the blade trying to keep the material removal consistent.

[bradp]

I learned a lot from this thread:

-Brad

 

[carusoam]

I met some nice MSers and their family because of that thread! 

Best regards,

-a-

[Shadrach]

1 hour ago, bradp said:

I learned a lot from this thread:

-Brad

Thanks Brad,  I actually posted to that thread!

 

[MB65E]

I'd remove a fitting, or see if you can depress the tiny ball on the zerk fitting to relieve pressures. The last service may have pressurized the hub. Our prop was spitting grease post annual. I only use one or 2 pumps now. I used to wait until fresh grease came out the back side... My prop shop said that during the overhaul, I had enough grease in the hub to last another 10 years. All this stuff is over serviced anyway. 

Get ready, because I can guarantee the next overhaul will be more than his quoted $1800. We had 5k in a recent overhaul on ours. Our propeller had the wrong shaft in it, worn pilot hole on the hub, corrosion on all the races. The blades are from 1967 and still made it through the inspection.

-Matt

 

[jetdriven]

Ship to stallings or San Antonio propeller.  Neither will BS you. My teardown reseal with new paint was 650$

[sreid]

Cody Stallings has been willing to do IRAN work on my prop in the past. I have been extremely pleased with the results and customer service. 870-208-5198

[Vance Harral]

From the other side of the coin... we just delivered our prop on Monday to a local shop for an overhaul.  Pretty much the exact symptoms you're seeing: 10 years since last overhaul (got a new hub at the time on the Hartzell half-price deal), throwing a little grease.  In our case we also have numerous nicks filed out over the years, which are a bit ugly though I'm sure only cosmetic.

Why an overhaul instead of IRAN?  Almost entirely because the number of prop shops in Colorado had dwindled to one when we made the decision - though a second has just recently (re)opened.  We wanted a local shop, and as in your case, the shop won't do an IRAN on a 10-years-since-last-overhaul prop.  Why is anyone's guess.  Maybe liability, maybe lack of interest in dealing with economy-minded customers, or maybe what they legitimately believe to be safety reasons.  The point is, our options were to overhaul locally or ship the prop out of state for IRAN.  We chose the former.  It avoids shipping costs and risks.  It also means if they call us next week and say there's corrosion, or the blades need to be condemned, or whatever... we can say, "OK, I'm on my way right now to look at it.  I want to see the corrosion, blade measurements, etc.  They know we're local, and I like to think that helps keep them honest.  Not that they couldn't still grind the blades into oblivion if they were incompetent or malicious, but at some point you have to trust a shop based on their reputation, and this particular one has been in business over 30 years.

Assuming no issues, the overhaul will run about $2500, which is more expensive than some of the quotes I'm seeing here.  But we have money in the partnership kitty for stuff like this.  Even if it were 100% out of pocket, it's not so bad divided by 4 partners.  If there are issues, we'll deal with them then.  I'll report back here on Mooneyspace if anything interesting comes of it.

[jetdriven]

What happens is they call you can tell you that your blades are now ground below limits or the hub has corrosion and they have already destroyed it.. The repair station game.  They simply notify you that you had a prop before and you dont anymore. But you have a bill.  However, they'll keep your hub or any other parts that are airworthy for the cost of tearing your prop down and condemning it. Strange how that works. 

[Vance Harral]

Yes, there's always a chance a shop can $crew you.  All you can do is ask for opinions and research reputation, and balance that against the convenience and (limited) control you have with a local shop.  Best as I can tell, the only complaint about the shop we're using is they don't do IRANs past the manufacturer's TBO recommendations.  Other than that, plenty of good reports, and no stories about destroying hubs or blades without prior discussion.

[jonhop]

Amazing timing of this thread... I just had my prop picked up by American Propellers this morning. It started leaking grease for the past several flights. How much depended on how hot it was. It's last overhaul was in 2001, so it was definitely due. I got three quotes from reputable shops that ranged from $2700 to $3000 and all offered free transportation. I went with American Propellers because they are an official McCauley shop. I hope they don't give me the bait and switch.

[MB65E]

Todd at American Propeller will treat you right. 

They have done 2 MT's and a MAC in the past for me. 

The truck leaves only on Tuesday so that's the only catch. I missed the truck by a day and had to wait a week. That's the only thing that went funny on the last MAC overhaul I did with them. Everything else was really nice. 

Nice shop,

-Matt

[Shadrach]

Started throwing grease again on a short hop today. Overhaul is $1800 here. Still deliberating.

[MB65E]

Just wait till it cools off guys... 

I bet prop shops get slammed during the summer!!

-Matt

[Shadrach]

3 hours ago, MB65E said:

Todd at American Propeller will treat you right. 

They have done 2 MT's and a MAC in the past for me. 

The truck leaves only on Tuesday so that's the only catch. I missed the truck by a day and had to wait a week. That's the only thing that went funny on the last MAC overhaul I did with them. Everything else was really nice. 

Nice shop,

-Matt

I'm sure they're great, but I'm in Maryland.

[Vance Harral]

$1800 does seem like a remarkably good price for a full overhaul.  If you feel comfortable with the shop and want (or will accept) the blade work that goes with a full overhaul, I'd take that deal.  You might ask them how they manage to do it for so much less than other shops, though.

The shop we're using is Rocky Mountain Propeller.  They have a video explaining how they overhaul props (see link below).  Maybe you can compare what you see in that video with the tools and facilities available at the $1800 shop.

 

 

[Shadrach]

8 hours ago, Vance Harral said:

$1800 does seem like a remarkably good price for a full overhaul.  If you feel comfortable with the shop and want (or will accept) the blade work that goes with a full overhaul, I'd take that deal.  You might ask them how they manage to do it for so much less than other shops, though.

The shop we're using is Rocky Mountain Propeller.  They have a video explaining how they overhaul props (see link below).  Maybe you can compare what you see in that video with the tools and facilities available at the $1800 shop.

Vance. I think the price is likely a reflection of them having been in business for more than 40 years under the same ownership. No mortgage, equipment is paid for, processes and procedures honed through years of experience. 

 

 

[Vance Harral]

3 hours ago, Shadrach said:

Vance. I think the price is likely a reflection of them having been in business for more than 40 years under the same ownership. No mortgage, equipment is paid for, processes and procedures homed through years f experience. 

Makes sense to me, glad you have that shop as a nearby option.  Good luck with your choice.  I'll try to remember to report back here when our work at RMP is complete.

[Cody Stallings]

IRAN that Sucker.

Your not part:135

Its your Propeller, it should be your choice.

Grease leak is a sign of Hard seals or Over serviced!!!

To fix that, an O/H is way to evasive.