Grease streaks on prop - When is it a problem?

[WingnutWick]

Hello all,

Relatively new to the constant speed world with the addition of the RV-10 to the fleet so I am reaching out to get an idea of how normal it is to have a little grease (I assume it's grease) streaking out of the prop after a few hours of flying. Standing by for insights and what it means going forward.

See photo.

Thank you!
CW

 

[MacCool]

Personally, I'd be scheduling a trip to the prop shop if I saw any grease streaking on the prop.

 

[stigaro]

In light of the recent thread, how long was your prop sitting around in storage?

 

[Ralph Inkster]

Based on your picture, I’d be sending that prop in for re-sealing.

 

[Dan 57]

consulting the manufacturer provided manual might be an idea... here what MT say for their prop serie:

Grease leakages

The first run-up of a new or overhauled propeller may leave grease on the blades and inner surface of the spinner dome. This is normal and do not mean that it will be a continuing grease leakage.

Remove any grease on the blades or inner surface of the spinner dome by using a mild solvent.

Minor grease leak which can be seen on one or all blade root(s) and spinner should be monitored if it gets worse.

If the grease leak does not spray more than 7 inches (18 cm) on the blade surface from the blade root outside the blade ferrule in 5 hours of operation, it is defined as minor and should be only monitored!

Continued grease leakage after 20 hours of operation from first leakage requires repair at an authorized service repair facility within 5 operating hours.

In case of doubt contact manufacturer!

 

[WingnutWick]

In light of the recent thread, how long was your prop sitting around in storage?

Not sure on this as I'm the 3rd owner but I do know that the plane sat for a good portion of a year with little usage. I've been told this can lead to some separation of the grease and cause streaking, is this what you're referring to?

 

[stigaro]

Not sure on this as I'm the 3rd owner but I do know that the plane sat for a good portion of a year with little usage. I've been told this can lead to some separation of the grease and cause streaking, is this what you're referring to?

This thread (https://vansairforce.net/threads/lo...zel-prop-and-consequences.226656/post-1766340) has an in depth discussion of the potential perils of long-term propellor storage. Consensus is basically that a Hartzell prop has a two year span that you can store it. After that, the grease will separate and seals dry up. The combination leads to grease slinging out of the hub, likely as you're seeing. ~$1500 for a reseal.

 

[WingnutWick]

This thread (https://vansairforce.net/threads/lo...zel-prop-and-consequences.226656/post-1766340) has an in depth discussion of the potential perils of long-term propellor storage. Consensus is basically that a Hartzell prop has a two year span that you can store it. After that, the grease will separate and seals dry up. The combination leads to grease slinging out of the hub, likely as you're seeing. ~$1500 for a reseal.

Thanks for the info!

 

[M McGraw]

Thanks for the info!

Slow down just a minute, take a deep breath. I had a similar issue with my brand new prop. I loosened the blade retaining bolts slightly and retorqued. The issue has not reappeared in 1100 hours. If it does not work then move on to actual inspection/maintenance. It will only cost you about 15 minutes to try it.