Maintaining a hartzell cs prop

Hi,

Its condition inspection time and I greased my prop hub per the manual and am wondering how critical is balancing the grease load? I ran out midway side 2 and the grease gun had a hiccup pumping.

Side 1 good, side 2 probably a short load.

Panic or…

Thanks.

How much grease are you using? Too little is almost certainly better than too much.

If you're going by the manual (< 1oz) I can't imagine that causing enough of an imbalance so near the center of mass as to cause a problem in the short term. If it were me I'd fly it then put some in the other side once you have some.

And I agree with Bob, go easy on the stuff. Too much over time and it can start coming out the seals. Ask me how I know.

Why?

Education going on here....


Is the recommendation due to mechanical reasons, simple mess all over the plane, etc?

Thanks,
Mike

Time for me to fess up, kinda related here. You know when you pay more for something you think it's better. I had that philosophy with the grease. Aeroshell #6 is hard to find and more expensive than bearing grease so that is what I used on my wheels last service. Well today a year later it's time to service the wheel bearings. This grease had hardened and dry out. It was a mess. Hadn't had anything like this before with standard grease. Washed the mess out and greased with wheel bearing grease. Lesson learned again.

MJarreau said:

Education going on here....

Is the recommendation due to mechanical reasons, simple mess all over the plane, etc?

Thanks,
Mike

Click to expand...

For the first 5 years or so that I had my plane I dutifully put several pumps of grease at each annual. At one point I noticed streaks coming down the blades from the hub and some winding up on the windshield. A local mechanic said yeah that's coming out the blade seals which can happen if you fill it up even with the proper procedure of opening the one side to let any excess come out. Now I'm much more sparing, only a couple of pumps now and then. The prop has been apart twice for inspection in 1600 hrs and no corrosion or other problems ever encountered. I've since read in a few places that this is not uncommon and to be sparing with the grease.

Disclaimer: I'm not a mechanic, just someone who wound up with grease coming out the prop hub and read some things and talked to some mechanics.

I asked around a lot about this as my prop was shipped with aeroshell#6 and not the new synthetic grease. The advice I got was to use just a few pumps as the majority of props they had in were significantly overserviced. #6 has better cold weather performance which is more relevant to turbine operations in the flight levels. They recommended #5 as it has less separation issues (wax and liquidy oil). They are both mineral greases that can be mixed per the hartzell service bulletin. My regime is 4 pumps at annual. The hartzell manual has very good directions on the service procedure.

It is really worth taking a few minutes to search the forums. Tons has been written on this topic. There was a thread not more than a month or two ago that had great information.

Thanks, mountainride

That clears up a question or two I had.


GRKohler
Ohio

Hartzell’s recomendation is to do a dynamic balance. Makes sense, resolves the issue nicely, and restores my confidence in the prop.