Propeller oil /grease speckles

Home 2024 Forums Opening Section Maintenance Issues Propeller oil /grease speckles

Viewing 15 posts - 1 through 15 (of 18 total)
  • Author
    Posts
  • #83907

    Has anyone experienced leaking around propeller hubs of McCauley Sabre Tip props? The attached photo shows mine. These are only 900 since new with overhaul 100 hours ago and 2 previous re-seals and O-ring replacements. I understand McCauley knows this to be an issue and they are coming to look at my props tomorrow. Any help is apprectiated.


    Attachments:

    #96867

    Yep sure have on several props. You have a small leak going on. Sometimes it will go away if the airplane is flown, but more often than not it does not get better. The solution is to pull the prop and send to prop shop for reseal job.

    #96870
    cochrane
    Participant

      Is the oil is from the propeller or the front crankshaft seal? Propellers are normally filled with a colored oil (red?) so that you can identify where it is coming from. If it is the crankshaft seal that is a relatively simple repair.

      #96872

      I’m not sure whef at this point. I left it with mechanics today and they will be pulling the spinners to investigate in the morning. It is not red-dye colored oil but rather a brown grease / oil looking mixture. The McCauley folks wanted us to leave it as is until they arrived. Thanks

      #96878
      sworley
      Participant

        I’m seeing this as well and on both sides. I figured it was such a small amount it was normal. Is it going to be worth the effort to fix it?

        #96879
        rwelsh
        Participant

          Mine Q Tip Hartzells have been doing that for years. I figure I can spend the $2K for AvGas and wipe the spots off once in awhile.

          #96881

          I’ll let you know the outcome of whether it is worth it or not. While it doesnt represent any immediate flight danger, the grease and oil buildup inside (where you can’t wipe off) can cause corrosion issues. Bottom line, it may be common but it’s not correct. I hope for the best and will advise of the outcome.

          #96883
          quote COCHRANE:

          Is the oil is from the propeller or the front crankshaft seal? Propellers are normally filled with a colored oil (red?) so that you can identify where it is coming from. If it is the crankshaft seal that is a relatively simple repair.

          Would be unlikely to see it here for the front prop seal. you would see it where the crank shaft exits the engine and then aft. My right crank seal had failed and working with my A&P it was fairly easy to remove the prop, pull out the old seal, and put in the new + new prop bolts. Easiest way to get the seal on without the special tool is to put a zip lock bag on the prop hub, oil it up with engine oil, boil some water and put the seal in it. Then, fish out the seal with some tongs, hand it to your mechanic, and let him stretch it over the hub and into position. Would have made a funny video! He recommended against the split seals as they fail early. Mine failed in the usual way, it was old and rust/debris on the surface of the shaft cut into the seal until it started leaking a bit. The left one is not leaking but I keep an eye on it.

          While you have the prop off, good opportunity to replace the prop o-ring (which hardly ever fails) and clean out the center of the crank shaft (or jack shaft in a GTSIO-520) of lead deposits that fling out against the inside of the tube (and don’t help balance) (Yet another thing that will be better when lead free G100UL is approved as a 100LL replacement)

          I suspect multi engine pilots ignore minor prop leaks more often than single engine as it does not take much grease on a windshield to ruin the view. I have no idea on the risks of delay, if any.

          If you do have the prop off for any reason and the prop seal is older than ~ 5 years it would not be a bad idea to replace the crankshaft seal as the additional risk of maintenance induced damaged is low and the incremental part cost is ~ 40 bucks.

          Eric

          #96897

          Eric, Thank you very much for your post. I took the liberty of sending your comments to my shop JA Aero here in Chicago. Curious to hear his response and see his actions. We are still waiting on the prop shop to complete their analysis and for McCauley to render a verdict. Again, thanks….hopefully get to use this technique. Best regards, Mike

          #96899
          quote MBUCK:

          Eric, Thank you very much for your post. I took the liberty of sending your comments to my shop JA Aero here in Chicago. Curious to hear his response and see his actions. We are still waiting on the prop shop to complete their analysis and for McCauley to render a verdict. Again, thanks….hopefully get to use this technique. Best regards, Mike

          Glad to help out Mike. Let us know how it turns out.

          #97680

          I own an ’81 C340A, Hartzell Q-tips which has recently developed the same oil/grease spray problem on the left engine only.

          I’ve replaced the crank seal and rear prop seal and have not solved the problem. Debating whether or not to send in the prop for an IRAN.

          How did your problem turn out??

          #97683

          Generally, I’m not real fast about sending props out for overhaul unless there is evidence of a problem. Especially if the plane is hangared in a dry environment. That being said, once there is a leak, I believe it is imperative that you send the prop to a shop for a repair or overhaul. The leak could be just a seal or it could be many other problems, such as corrosion. You do not want to fly with a bad prop. Slinging a blade could be expensive at best and disastrous at worst. I am a true believer that if its a safety issue, I never wait for tomorrow to fix it.

          #97687
          quote FBECKMAN:

          I own an ’81 C340A, Hartzell Q-tips which has recently developed the same oil/grease spray problem on the left engine only.

          I’ve replaced the crank seal and rear prop seal and have not solved the problem. Debating whether or not to send in the prop for an IRAN.

          How did your problem turn out??

          I did have both props pulled and sent out for inspection (by McCauley) and ultimately were re-sealed. It involved placing a Teflon sleeve on the hub for better sealing. After that, a balance and a fresh paint, they have performed perfectly…no oil, and well balanced. I’m confident this was the right course of action and the folks at JA Air did a great job managing the process. Hope you get yours under control.

          Mike

          #97772

          Coming from Addison to San Antonio. Thank God I landed at San Antonio for refueling and saw the beautiful Alex Gutierrez 340 (we did not meet, Alex). If I have the problem here at Mexico, it will be kind of a disaster.
          After going to breakfast came back and saw oil leaking from my right prop.
          I called the guys at Cutter and going to take the prop to a prop shop.
          Never happened before. The prop was taken off about 10 to 15 hours ago for balance.

          Rodolfo
          1978 C340A RAM VII


          Attachments:

          #97776

          That does not look like prop grease, that looks like oil. There is one o ring for where the prop meets the crank shaft bolt circle. This would be the most likely place. Why did they remove it for balance? Usually they do a dynamic balance with the prop on the plane. It’s possible this o-ring did not seat well – but then I would have expected oil everywhere if so. Were you able to check and see where on the prop it was leaking from?

        Viewing 15 posts - 1 through 15 (of 18 total)
        • You must be logged in to reply to this topic.