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Hartzell CS Prop slinging grease

dekagram

Member
Recently, my 12 year old - 800 hr CS Hartzell C2YR- prop began to sling grease from one blade. I retorqued the spinner / prop bolts with no effect.**Before I send the prop off for a 2,500-3,000 overhaul, I thought of reaching out to you guys first to see what your experience / advise on reseals / overhauls.* Any recommendations of a prop shop in the Southeast?

Thanks in advance,

Greg*
 
Check your manual, but I believe you will find that prop has a 72 month calendar TBO as well, if you care to follow it.

If you do have it overhauled, you can opt to replace the Aeroshell 6 with 5. It has better separation qualities but you are limited on the low temp end to something like -20C, again check your manual.
 
I know posting pictures is more difficult now with less free hosts... but how much grease. A little is OK and normal. To service you removed one zerk and grease it slowly from the 2nd zerk slowly, until you get squeeze out; don't pressurize hub with grease. Yes heated hanger, room temp grease is best. Keep an eye on it. I agree cold temps may make grease spitting more.

Here is my advise "evidence of grease from hub on blades." Solution; "Remove evidence." Get a rag and wipe it off each flight. :D
 
That's not quite correct for Hartzell's. From the Hartzell Propeller Owner's Manual, page 6-9 & 6-10:

CAUTION 1: OVER-LUBRICATING AN ALUMINUM HUB PROPELLER MAY CAUSE THE GREASE TO ENTER THE HUB CAVITY, LEADING TO EXCESSIVE VIBRATION AND/OR SLUGGISH OPERATION. THE PROPELLER MUST THEN BE DISASSEMBLED TO REMOVE THIS GREASE.
...
CAUTION 4: DO NOT ATTEMPT TO PUMP MORE THAN 1 FL. OZ. (30 ML) OF GREASE INTO THE LUBRICATION FITTING. USING MORE THAN 1 FL. OZ. (30 ML) OF GREASE COULD RESULT IN OVER SERVICING OF THE PROPELLER.

(8) Pump a maximum of 1 fl. oz. (30 ml) grease into the lubrication fitting, or until grease emerges from the hole where the lubrication fitting or lubrication hole plug was removed, whichever occurs first.

NOTE: 1 fl. oz. (30 ml) is approximately 6 pumps with a hand-operated grease gun.​

(a) For all tractor or pusher propellers with clockwise (standard) rotation when viewed from BEHIND the aircraft, apply grease to the lubrication fitting that is in the ENGINE-SIDE hub half.

(b) For all tractor or pusher propellers with counter- clockwise (backward) rotation when viewed from BEHIND the aircraft, apply grease to the lubrication fitting that is in the CYLINDER-SIDE hub half.
I agree don't over grease and follow the manual. You get some squeeze out after only a few pumps (less than an OZ). Great reference thanks. Vibration with grease loss should be addressed. I was aware you can over grease, but having two zerks with one removed should not force grease into hub... but follow manufacture instructions...
 
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Prop shoo

I?ve been using Texas Aircraft Propeller in Houston 281-485-4400. They run a truck around the region and will pick up and deliver. I have been satisfied with their work and pricing.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
I know the manual says this

NOTE: 1 fl. oz. (30 ml) is approximately 6 pumps with a hand-operated grease gun.

but when I look at the specs for a variety of grease guns, they're all over the map in terms of how much they dispense. I've always done 6 pumps, but if you're really anal retentive, it seems that each model of gun is different and it may be more or less than 6. Like, a lot more. Or less.

I doubt it matters *that* much, but YMMV.
 
After 1950hrs and 18 years I had the prop shop do a IRAN (inspect,repair,as necessary)on the prop. Prop was not slinging grease but I felt a slight imbalance.
Hub was impacted with grease after 6 pumps x 18 years. They cleaned it out, replaced seals and said Hartzell recommends only 2 pumps in each blade at annual.
Cost was $700. Much cheaper than a overhaul.
Hangared and flown regularly.
 
open


Thanks for replies...

I'm thinking that after 12 years, the blade retaining seals eventually become hard and flatten out. It's impossible to know whether a little grease on a blade is a nuisance leak from a seal or a crack developing.

All the best,

Greg
 
I had read and was told four pumps in the past. I don't have the manual handy to see where I read it. But it was four pumps or till grease comes out of the other hole.
 
I've had a number of these props apart and have resealed them myself so I know how the bearings and races work. It is my opinion that greasing these propellers does nothing but cause problems. It is in essence a sealed bearing and there is not enough movement in the bearing rotation (around 1/8" or so) to warrant yearly regreasing.

There is virtually no way for contaminants to enter the bearings and races.

I would be willing to bet that if there was ZERO grease in the bearings nothing adverse would happen.

Why doesn't the manufacturer employ dry-film lubrication so that there is no reason to ever grease them?

I could go on but my $.02 is to not bother.
 
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to dekagram

From the pic, your diagnosis is correct - a leaking seal. Depending on your flight sched, and $$/ comptroller issues, fly it or IRAN it [NOT "overhaul"]. It will get worse, but primary issue at this stage is cleaning the grease off. {I'm assuming this is not a 15 minute accumulation, of course.]
AS for 'annual greasing': the prop needs what it needs, not what you want to give it. '2 pumps' '4' '6' are all rubrics that have more to do with maintainer's habits than the prop's needs. Read the Hartzell book and do it their way [or MT's, or WW's if that's what you have].
 
On an 800 hour prop DO NOT have it overhauled! If it keeps leaking, have it resealed,ONLY. On an overhaul they remove 5/1000 inch,or more, by grinding/sanding off the thickness of the blades. The result after a few overhauls is the blades may no longer meet minimum thickness or chord and need to be scrapped.
 
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