romair Posted June 13, 2013 Report Posted June 13, 2013 So yesterday I went and tested out the glide ratios for Xavion. This included pulling the propeller all the way out several times together with the throttle in order to get the right configuration. When I landed I noticed some possible oil smudges on both sides of the propeller. I had seen this before, but not as much as last night. Of note, during my pre-flight check I always take a look with the flashlight at the propeller hub where the blades are attached. There has always been a bit of black oil/grease right where the blades come out of the hub, and always looked old. Last night, after hangering the plane, there seemed to be slightly more oil, and it glistened into the flashlight like it was new seepage, not old. Ran my fingers on it and it did appear to be new. That being said, the quantity is still negligible. The airplane is an '89 J model, never had the engine or propeller overhauled. 1800 total hours on both. I am attaching some pictures. What do you guys think is going on? I wanted to put another 100 or so hours on the engine before overhauling both the prop and the engine, so I really don't want to take the propeller off. Could it be because of the extra-stress I put on it by pulling the prop all the way out several times when gliding? The first 2 pictures show the streaking on the blades, the third one shows the streaking at the hub (picture taken through the opening in the spinner, where the blade goes into the hub). Thanks Stefan '89 M20 J Quote
co2bruce Posted June 13, 2013 Report Posted June 13, 2013 Can't imagine its anything but the seal. but I'm no mechanic. Quote
Marauder Posted June 13, 2013 Report Posted June 13, 2013 There is a member here (Cody) who works in a prop shop who could give you the best advice. From what you are describing, it sounds to me that it is the seal leaking. I think I remember Cody (Stallings I think is his full name) mentioning something about McCauley props and leaks. That is a lot of years without a prop overhaul! Mine has been overhailed twice in the past 22 years. Quote
OR75 Posted June 14, 2013 Report Posted June 14, 2013 oil or oil mist around the prop means it is time to O/H or reseal the prop Quote
Hank Posted June 14, 2013 Report Posted June 14, 2013 Don't overhaul, get an IRAN. Then no metal is removed from the blades unless it is necessary. Quote
mikefox Posted June 14, 2013 Report Posted June 14, 2013 We are starting to see a bit of oil on our cowl surrounding the spinner, and a few spots migrating further up the cowl and onto the windscreen. 1989 M20J as well. Sadly I think the prop will have to come off this summer. Second time in 10 years we have had to reseal the prop. Anyone else have issues with the prop seals on M20J's? Quote
Cody Stallings Posted June 14, 2013 Report Posted June 14, 2013 It would be the 1633-56 O-rings. In a non-oil filled propeller they last several yrs, you got an extra 15 yrs out of yours... with your prop it will stop leaking at some point, don't think it fixed itself. It's just out of grease. If your propeller is in good working order, an the face of the blades don't look like you have been taken off at a rock quarry, I would opt for a flush an re-seal...... My 2 cent 1 Quote
Marauder Posted June 14, 2013 Report Posted June 14, 2013 It would be the 1633-56 O-rings. In a non-oil filled propeller they last several yrs, you got an extra 15 yrs out of yours... with your prop it will stop leaking at some point, don't think it fixed itself. It's just out of grease. If your propeller is in good working order, an the face of the blades don't look like you have been taken off at a rock quarry, I would opt for a flush an re-seal...... My 2 cent Sorry Cody! For some reason SWTA Russell Stallings stuck in my mind! Quote
Cody Stallings Posted June 14, 2013 Report Posted June 14, 2013 Not a problem..... I have been called worse... Quote
AmigOne Posted June 14, 2013 Report Posted June 14, 2013 Bought my 1968C with a similar leak which I attributed to stiff/dry oil seal due to a lack of use because the aircraft had been idled for a long time (the owner's was sick and had passed away when I bought the airplane). I negotiated a price to account for a prop o/h hoping that the leak would stop. Although minor the leak did not stop so I bit the bullet and had it overhauled and a reconditioned hub (no AD) installed. $2300 (East Coast Propellers, Pa) Quote
Cody Stallings Posted June 14, 2013 Report Posted June 14, 2013 You got a B suffix hub an O/H for $2300?.... That's a smokin deal Quote
bumper Posted June 14, 2013 Report Posted June 14, 2013 We are starting to see a bit of oil on our cowl surrounding the spinner, and a few spots migrating further up the cowl and onto the windscreen. 1989 M20J as well. Sadly I think the prop will have to come off this summer. Second time in 10 years we have had to reseal the prop. Anyone else have issues with the prop seals on M20J's? Oil on the leading edge of the cowl and up onto the windscreen can also come from an engine oil leak. I had this happen and the problem was an oil seep at the case halves at the top of the engine near the lifting eye, Simply tightening a loose case bolt stopped the leak - - and the oil on the windscreen magically stopped. BTW, when it happened, I thought for sure it was the crank nose seal . . . but oil on the windscreen in flight sure does get your attention! Sounds weird, I know, how could this possibly occur? Since the Mooney does not come stock with a forward top baffle, like some experimentals (Van's RV) and some more modern designs, upper deck high pressure air can move forward and out the cowl to spinner gap. Near as I can figure, the back of the spinner plate may be acting like a centrifugal fan helping to suck out the upper deck air. It sure was vacuuming up the oil from my leak, which showed as an oil damp spot about 15 sq. in. in size. Adding a top front baffle, on another aircraft I own, lowered climb CHTs by 50 F. bumper Quote
NotarPilot Posted June 14, 2013 Report Posted June 14, 2013 What's the general consensus of when to overhaul your prop? I haven't had mine overhauled in some 15 years (off the top of my head) but it seems to be running strong with no issues. What do you all think? On condition? Quote
yvesg Posted June 14, 2013 Report Posted June 14, 2013 What's the general consensus of when to overhaul your prop? I haven't had mine overhauled in some 15 years (off the top of my head) but it seems to be running strong with no issues. What do you all think? On condition? In Canada we have no choice. The regs say it has to be done every 10 years. Mine is due in two years. Wondering why the regs are different. Perhaps because of cold temperature operations? Would be nice to find out if leaking props happen more from the northern states? Yves Quote
Marauder Posted June 14, 2013 Report Posted June 14, 2013 What's the general consensus of when to overhaul your prop? I haven't had mine overhauled in some 15 years (off the top of my head) but it seems to be running strong with no issues. What do you all think? On condition? I have has mine done twice in 20 years. The main reason is that I have a friend who an an E and this happened to him: http://dms.ntsb.gov/aviation/AccidentReports/wck5janu3a1wtbj1e4kwslm31/W06142013120000.pdf Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.