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Hartzell servicing question

Bsquared

Well Known Member
I have a 74” 2 blade aluminum CS prop on my -14A. I have serviced it twice so far with the type 5 grease and the recommended number of strokes on the grease gun…..once after 2-3 hours TSN and again at my 1st condition inspection a year later. I removed the plug opposite the lube fitting both times and I did not see any grease being pushed out when I pumped in the fresh grease. Is this normal? I was expecting to see some grease come out like when you service a ball joint on a car.
 
First verify you are removing the correct plug. For that matter, remove both plugs before you start just to make sure.

For a new prop I find it takes a little more grease the first couple of times.

Carl
 
I have a RV-4 Hartzell CS on IO-360. I was experiencing the same thing. I had a problem because my grease gun would not always give a full stroke. Anyway, I checked to make sure there was not hardened grease blocking the exit by probing with a piece of stiff wire. Then I gave a few more careful stokes and finally got grease out like I expected. I fly quite a bit and grease the prop every 100 hrs which ends up a couple of times a year. Now I get grease out almost immediately. I think I'm using Aeroshell 6.
 
First verify you are removing the correct plug. For that matter, remove both plugs before you start just to make sure.
Carl

Newer Hartzells now ship with 2 zerk fittings and 2 plugs, so it’s hard to get it wrong.
The manual seems to emphasize to not over-grease.
Finally, newer Hartzells now come with a different, hard to find grease, which is not compatible with Aeroshell 5 or 6.
 
Just had mine overhauled and the shop said not to follow the book. He said max 2 strokes. Every two years. Might want to Contact Hartzell and verify. Said it was a new service bulletin?
 
Just had mine overhauled and the shop said not to follow the book. He said max 2 strokes. Every two years. Might want to Contact Hartzell and verify. Said it was a new service bulletin?

I just did a search of ADs and SBs last month for my annual Condition inspection and did not see any new Hartzell bulletins. I guess I should call them.
 
Specifies the new type of grease.

I believe Hartzell says not to mix grease - use what is originally applied. The “new” grease should only be used on new props where it was originally used at Hartzell, although they may convert older props to this grease at overhaul.
 
I believe Hartzell says not to mix grease - use what is originally applied. The “new” grease should only be used on new props where it was originally used at Hartzell, although they may convert older props to this grease at overhaul.

The NYCO 3058 grease is a synthetic and must not be mixed with Aeroshell 5 or 6. Synthetics and petroleum based greases do not commingle. The petroleum grease can actually create a barrier to the synthetic in establishing a high film strength barrier with the wear surfaces.
 
I have a 74” 2 blade aluminum CS prop on my -14A. I have serviced it twice so far with the type 5 grease and the recommended number of strokes on the grease gun…..once after 2-3 hours TSN and again at my 1st condition inspection a year later. I removed the plug opposite the lube fitting both times and I did not see any grease being pushed out when I pumped in the fresh grease. Is this normal? I was expecting to see some grease come out like when you service a ball joint on a car.

I spoke to Hartzell about this, they said to follow the book on service, add a MAX of one ounce per fitting and specified do not overfill. It seems they don’t want you to add “a little more” in order to get some grease to come out of the other hole. Always grease from leading edge fitting on a tractor prop. Only use the grease number that the prop was built with, don’t switch to another number unless the prop is town down to clean out and replace all of it, which at that point they’ll probably do the GYCO stuff and re-sticker the hub. To figure how many pumps 1 ounce is, you may have to measure it, as guns may differ. They do not want you to keep pumping until it comes out the other side.. one ounce max!
 
Hartzell is relatively local to me. They came and spoke to a local group. One of the topics that caught me off guard was that they showed photos of failed props due to too much grease. The photos were pretty bad. Grease was in every nook and cranny until all available space was full.

I also have my prop overhauled this past year. As mentioned, they converted it to the new synthetic grease. My only complaint was the expense and lack of availability though other sources. I could buy it through the prop shop at a ridiculous price, but for almost a year I couldn’t find another retail source. I recently discovered the ACS is now stocking it, it’s still expensive, but about half the prop shop price.
 
Bob

The new grease maybe expensive but if it stops the corrosion on the bearing races it’ll be far cheaper when it comes to overhaul. Here’s hoping.

Regards

Peter
 
Hartzell says both Aeroshell 5 and 6 are compatible, no problem mixing them. However, one of them, can't remember which one, is being phased out, and replaced with a full synthetic, I think it is aeroshell 22, service instruction says to not use the synthetic grease with the older petroleum grease, unless the prop has been totally disassembled and cleaned, then one can start servicing it with the synthetic grease.

DAR Gary
 
Below is a pic I took at the prop shop I work at (35years). The reason this was sent in was because the prop was sluggish in operation. The reason for being sluggish is that the fork that connects the pitch change rod to each blade pin, is not designed to go through all that grease in the center of the hub. There should be an airspace in the center of the hub, not all that grease in the picture.


See Hartzell Owners manual 115N and click on the link and go to page 6-7. All the instruction for prop lubrication, of a Hartzell "Compact" propeller, you need is there on the web for your enjoyment.
https://hartzellprop.com/MANUALS/115N-0000-A.pdf



A few things here. A propeller is a giant centrifuge that tends to separate grease back into the stuff it is made from. Mainly a waxy type thickener and oil. I like the old Aeroshell #5 that we used for decades in props. I do not like #6 that has been the factory prop fill for a while. Over the years I have seen many props with Aeroshell #6 in them that have the grease separate during operation. The blade seals are designed to hold grease, not oil. Then typically the oil from the grease tends to leave the prop (through the blade seals) and leave the waxy thickener behind. So the thickener is not a good lubricant by itself and with little or no oil in the mix tends to make for corroded blade bearings ($$$). This is just my observation over the years. Hartzell now uses a factory fill with Nyco GN3058 grease, which in theory will be even better than the #6 and #5. I'm sure Harzell has tested the Nyco. I like that they are willing to go to a potentially better grease. Jury is still out on the Nyco as I've not seen one come apart yet. I do like that the Nyco is an anti corrosion grease we have used on other static propeller applications as an anti corrosive grease (Good stuff). The USN has even gone to great lengths to come up with a spec. for corrosion inhibiting grease (MIL-PRF-32014A).
When pumping in the grease, poke out the wax thickener that has most likely plugged the opposite zerk hole that you have removed (either the zerk or plug as the case may be). Use a piece of safety wire or something similar.
Insert/apply grease to each Zerk until grease comes out the other side, or until you have pumped approximately 1oz of grease (Approx 6 pumps/strokes on most grease guns). If you are unsure of how much 1 oz of grease is, or looks like, pump some out onto a paper towel on a cheap scale and count the strokes needed for 1oz.
Aeroshell #5 and #6 can be intermixed, per Hartzell. You are supposed to placard the aircraft restricting operation below -40°F if there is any Aeroshell #5 in the prop. I have to be honest, I've never seen that placard on any aircraft and there are thousands of Harztell props that have been lubricated with Aeroshell #5 over the decades.

This is what happens when you just keep pumping grease into the hub:
 

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I don't get over here much but I like to show people things of interest. I posted this on another forumn...
This is a McCauley C203 propeller that a friend owns. Cessna 182 application. He wanted it painted with Silver (Polane). I painted my prop the same way. I think it looks great! I took a short video of it after I assembled it and was checking operation. It only takes 30-40 psi of shop air to move the blades on the build table. This prop is oil pressure to increase pitch as are most SEL applications.
https://youtu.be/xAiY0mTO8Aw

Notice it only moves about 15°-20° or so. That is it for most single engine propellers.

Feathering propeller will move about 70° or so depending on application.
Reversing propellers are 90°+ depending on application.
The blades changing pitch while spinning with tons of forces applied is what keeps me up at night and also employed for the last 35 years.
 
Thanks Gentlemen, this is really good info!

The 1 oz that hartzell recommends is by weight? I understood it to be volume, which is kind of hard to measure.

Hartzell Propeller greasing amount.png
 
Thanks Gentlemen, this is really good info!

The 1 oz that hartzell recommends is by weight? I understood it to be volume, which is kind of hard to measure.

View attachment 20153

It says 1 fluid ounce or 30 ml which both are volumes. I think pumping grease into a 1 oz container, perhaps a shot glass would be doable.
 
It says 1 fluid ounce or 30 ml which both are volumes. I think pumping grease into a 1 oz container, perhaps a shot glass would be doable.

If I think of it at work next week, I'll pump 1 oz of volume (Shot glass) and 1 oz by weight and see what the difference is. Stand by...

I think either would get you in the ball park. They used to say in the 115N Owners manual that the 1 oz was approximately six strokes of your average grease gun. That statement has since been removed by Hartzell.
As someone who has greased several hundreds (possibly even more) of propellers I think the biggest problem is that people do not realize the hole on the other side, where the grease is supposed to emerge from, is plugged with that waxy build-up of the greases' thickener in that little bore. People just keep a pumping and a pumping, and a pumping, till the center of the hub is filled with grease. Then it can become sluggish and at that point it needs to come apart.

The object is to grease the blade shank bearings (1/2" diameter balls and races). The key is not fill the center of the hub with grease, by over-servicing.
 
If you service it every 100 hrs or annually how does the hub not eventually get overfilled with grease?
 
If you service it every 100 hrs or annually how does the hub not eventually get overfilled with grease?

The excess comes out the other side of the hub. Grease goes in one side and eventually out the other side. That it is why you remove the other side's zerk/plug and make sure the hole is clear with a piece of safety wire. If the grease does not come out the other side it is going past the blade retention bearing and pre-load plate and into the hub. Take a look in the 115N owners manual for the cut-away. That may help visualize?

The initial application of grease will probably take the most as once the prop spins the centrifugal force will force the grease outward towards the blade seals. Then at that point you are filling any air space, in the blade retention bearings. We cannot spin a prop at the shop so that little air may be there in the retention bearing after initial build up. Subsequent annual lubrication/greasing will probably use less as there should be no air pockets in the blade retention bearings.
 

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The excess comes out the other side of the hub. Grease goes in one side and eventually out the other side. That it is why you remove the other side's zerk/plug and make sure the hole is clear with a piece of safety wire. If the grease does not come out the other side it is going past the blade retention bearing and pre-load plate and into the hub. Take a look in the 115N owners manual for the cut-away. That may help visualize?

The initial application of grease will probably take the most as once the prop spins the centrifugal force will force the grease outward towards the blade seals. Then at that point you are filling any air space, in the blade retention bearings. We cannot spin a prop at the shop so that little air may be there in the retention bearing after initial build up. Subsequent annual lubrication/greasing will probably use less as there should be no air pockets in the blade retention bearings.

The thing that's confusing is why do they stress no more than 1 oz in the manual? But then also go on to say until some comes out, whichever occurs first.
 
The thing that's confusing is why do they stress no more than 1 oz in the manual? But then also go on to say until some comes out, whichever occurs first.

First, I’m REALLY appreciating Joe’s contribution here! Great to have someone who has done this for a living….

My interpretation (from prop shops is that you put no more than 1 ounce in - and if, before you get to the once, it starts coming out the other side, you stop! I figure if it starts coming out the other side, someone has overfilled it at some point….

And I am glad that Hartzell finally added a quantity other than “six pumps” - I always wondered “on which gun?”

Paul
 
First, I’m REALLY appreciating Joe’s contribution here! Great to have someone who has done this for a living….

My interpretation (from prop shops is that you put no more than 1 ounce in - and if, before you get to the once, it starts coming out the other side, you stop! I figure if it starts coming out the other side, someone has overfilled it at some point….

And I am glad that Hartzell finally added a quantity other than “six pumps” - I always wondered “on which gun?”

Paul

1st of all. No problem, I'm here to help. Please feel free to ping me on any prop questions. If I don't know, I'll be the 1st to tell you I don't know everything, but I know who to ask. I've been working on props for decades. I'm also a pilot and A&P, if that matters?
Once it starts coming out the other side the bearing is full of grease. Stop, bearing is full of grease, you are done. Not that the hub is full of grease, rather, that retention bearing is full of grease. If you have to keep pumping more than 1oz you are most likely filling the inside of the hub.
I'll check with Hartzell as far as intent, on that 1 oz recommendation. I think I have it right, but will ask intent.
 
1st of all. No problem, I'm here to help. Please feel free to ping me on any prop questions. If I don't know, I'll be the 1st to tell you I don't know everything, but I know who to ask. I've been working on props for decades. I'm also a pilot and A&P, if that matters?
Once it starts coming out the other side the bearing is full of grease. Stop, bearing is full of grease, you are done. Not that the hub is full of grease, rather, that retention bearing is full of grease. If you have to keep pumping more than 1oz you are most likely filling the inside of the hub.
I'll check with Hartzell as far as intent, on that 1 oz recommendation. I think I have it right, but will ask intent.

Ahhh that makes sense now. It just always seemed to me that the 1 oz/ coming out the other side conflicted with each other. Thanks for the pro explanation! I just always assumed the grease went to the same location/cavity, turns out not.
 
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