Van's Air Force
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Crankshaft Seal Leak
- Thread starter caborne3
- Start date
Hey Chuck, good to hear from you here!
I had a similar problem on the O-320 on my Grumman for years....and in fact, never solved it. Tried both one-piece and split seals to no avail. Eventually, the rest of the little "Genuine Lycoming" oil leaks from other common spots began to dominate, and I just gave up on the nose seal problem.
Sorry - not much help, I know...
Paul
I had a similar problem on the O-320 on my Grumman for years....and in fact, never solved it. Tried both one-piece and split seals to no avail. Eventually, the rest of the little "Genuine Lycoming" oil leaks from other common spots began to dominate, and I just gave up on the nose seal problem.
Sorry - not much help, I know...
Paul
Hey Paul, yeah this little issue is making Phase I not as fun as I planned. Engine runs good but I have to wipe down the cowl after every flight. It's good to know my case is not unique. I was beginning to think it was related to the higher relief pressure (475psi) governor but maybe not. I already called Whirlwind to see if they had any other customers with this problem. No joy. Goin' flyin' tomorrow anyway!
Chuck
Chuck
rv969wf
Well Known Member
Just some ideas.
Make sure you don't have any burrs on the crank prop hub/ flange. Something that I do is tape the crank flange with several wraps of 2" vinyl tape to make sure that the seal does not get cut on the crank flange and I use a brass rod that is polished with NO burrs and well oiled to install the seal over the hub. The seal will stretch better at high temps 90F+ days. I wouldn't install one on a cold day. After getting the seal "ONE PIECE type Seal over the crank flange I clean the O.D. of the seal with alcohol and let it relax to shape and size, then apply "PLIOBOND" contact cement to the case bore and O.D. of the seal and push it into place and then allow to dry overnight. Do not get any of the contact cement on the seal area and make sure there is a light film of oil on the seal surface and the crank. Something else that I have added is a split ring that bolts to the front of the case like on the Continentals to prevent the seal from blowing out if your crankcase breather freezes over for some reason. I've had good luck doing it this way and I've had more problems with the prop hub slinging grease out (Constant Speed) than the crank seal.
Make sure you don't have any burrs on the crank prop hub/ flange. Something that I do is tape the crank flange with several wraps of 2" vinyl tape to make sure that the seal does not get cut on the crank flange and I use a brass rod that is polished with NO burrs and well oiled to install the seal over the hub. The seal will stretch better at high temps 90F+ days. I wouldn't install one on a cold day. After getting the seal "ONE PIECE type Seal over the crank flange I clean the O.D. of the seal with alcohol and let it relax to shape and size, then apply "PLIOBOND" contact cement to the case bore and O.D. of the seal and push it into place and then allow to dry overnight. Do not get any of the contact cement on the seal area and make sure there is a light film of oil on the seal surface and the crank. Something else that I have added is a split ring that bolts to the front of the case like on the Continentals to prevent the seal from blowing out if your crankcase breather freezes over for some reason. I've had good luck doing it this way and I've had more problems with the prop hub slinging grease out (Constant Speed) than the crank seal.
LifeofReiley
Well Known Member
Split Ring
Can you share a pic of your split ring setup? Sounds interesting! We've installed crank seals in the same manner you decribe for years with no leaks or problems.
rv969wf said:
Can you share a pic of your split ring setup? Sounds interesting! We've installed crank seals in the same manner you decribe for years with no leaks or problems.
Very interesting! I'm in that very same boat with my 160-hp CS prop -320. Been through 5-6 seals in 7 yrs and 875 hrs, including 1 custom dual seal (current). Next mod will include applying a vacuum between the seals.
I had figured it was most likely my poor prep job on the crank seal area. But I also suspected the governor.
Any thoughts on altering any governor settings? Other ideas? I really am tired of the oily mess.
I had figured it was most likely my poor prep job on the crank seal area. But I also suspected the governor.
Any thoughts on altering any governor settings? Other ideas? I really am tired of the oily mess.
LifeofReiley
Well Known Member
Info
Here's some good info...
http://www.lycoming.textron.com/support/publications/service-instructions/pdfs/SI1324B.pdf
Also make sure you do not require an oversized seal.
Low Pass said:
Here's some good info...
http://www.lycoming.textron.com/support/publications/service-instructions/pdfs/SI1324B.pdf
Also make sure you do not require an oversized seal.
rv969wf
Well Known Member
Oil seal
I've been digging through photos and here are a few. Danged if I can't find a picture of the split ring I made, but you can see in the picture the added case bolt thru holes and the 3 each retaining holes for each split ring for the seal like on the Continentals. AJ
I've been digging through photos and here are a few. Danged if I can't find a picture of the split ring I made, but you can see in the picture the added case bolt thru holes and the 3 each retaining holes for each split ring for the seal like on the Continentals. AJ
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Bob Martin
Well Known Member
oil seals
My hangar mate has a 0-360 A1A with fixed pitch prop.
we are on the 4th seal also.
We have become very good at changing them.
We bought the 80.00 tool too.
plus hand polish the crank as best you can.
warm the one piece seal up in hot water before streaching it too.
I can't even see where they are failing at.
The old timers around the airport say to "keep at it....
one of them will hold......"
We are tired of waiting, even thinking about a tear down to look things over up front, in the slinger area.
It is a real PITA. for sure.
YOU ARE NOT ALONE on this one!
My hangar mate has a 0-360 A1A with fixed pitch prop.
we are on the 4th seal also.
We have become very good at changing them.
We bought the 80.00 tool too.
plus hand polish the crank as best you can.
warm the one piece seal up in hot water before streaching it too.
I can't even see where they are failing at.
The old timers around the airport say to "keep at it....
one of them will hold......"
We are tired of waiting, even thinking about a tear down to look things over up front, in the slinger area.
It is a real PITA. for sure.
YOU ARE NOT ALONE on this one!
smokyray
Well Known Member
No leaks, no runs, no...
Hi Chuck,
The original 0-320A in my Bandit had crank seal leaks. After extended aerobatics it would pop out after which I finally decided to replace the seal. During the re-installation my Dad (a long time engine builder) taught me a few tricks on installing the new seal. First, prep the crank flange by rubbing it down with sandpaper getting all the burrs and tape it as pictured above. Next you immerse the seal for about 3 minutes in boiling water. There is a special tool for stretching the seal around the flange. Permatex works great to hold the seal in, and I also added a crank seal hold-back plate to keep it from popping out. One thing to add, my airboat lycoming builder friend uses after market crank seals that work better. My new Airboat Super 0-320 in The Bandit has no leak issues whatsoever. I will try to find out where they come from...
Rob Ray
RV4
1500+ hours and counting
Hi Chuck,
The original 0-320A in my Bandit had crank seal leaks. After extended aerobatics it would pop out after which I finally decided to replace the seal. During the re-installation my Dad (a long time engine builder) taught me a few tricks on installing the new seal. First, prep the crank flange by rubbing it down with sandpaper getting all the burrs and tape it as pictured above. Next you immerse the seal for about 3 minutes in boiling water. There is a special tool for stretching the seal around the flange. Permatex works great to hold the seal in, and I also added a crank seal hold-back plate to keep it from popping out. One thing to add, my airboat lycoming builder friend uses after market crank seals that work better. My new Airboat Super 0-320 in The Bandit has no leak issues whatsoever. I will try to find out where they come from...
Rob Ray
RV4
1500+ hours and counting
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captainron
Well Known Member
Google: shaft surface finish for oil seals
Don't fall into the trap of trying to polish a mirror finish in the crankshaft seal area. This seal requires a degree of roughness to function properly. Here is a link:http://www.rlhudson.com/Shaft Seal Book/design-shaft3.html
Don't fall into the trap of trying to polish a mirror finish in the crankshaft seal area. This seal requires a degree of roughness to function properly. Here is a link:http://www.rlhudson.com/Shaft Seal Book/design-shaft3.html
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Rob, Any info available on the airboat seal? I've tried two different types on my IO-360-A1D, fixed pitch Sensenich and no joy yet. Thanks. Jim Graham RV-4 [email protected]
LifeofReiley
Well Known Member
Split Ring Hold & Seal
Rob,
I have one set of pictures of a design for a split ring seal hold-back plate. I would also like to see your design. Can I get a few pics? Also, do you have the contact info where the after market seal you are talking about can be purchased?
smokyray said:
Rob,
I have one set of pictures of a design for a split ring seal hold-back plate. I would also like to see your design. Can I get a few pics? Also, do you have the contact info where the after market seal you are talking about can be purchased?
Here's my situation. 160-hp, O-320 with CS prop. I just installed crank oil seal no 8 (guessing). Engine's got ~915 hrs over 8 years. Has had a leaky crank seal essentially from day 1.
I've had people tell me that I needed to ground the plane and overhaul the engine immediately. BS! It's got great compression (topped 150 hrs ago) and is very powerful & smooth - but leaky.
There's something - probably to do with the crank seal surface prep + the high pressure oil from the CS prop - causing the problem. BTW - the sealing sfc under a lip seal needs to be as smooth as possible to work effectively. Mine's marginal.
Regardless, I am continuing to think about alternate seal configurations.
I just removed a dual (back-to-back) seal. Made with two seals and a gland to contain the outer seal. Had the space between the seals piped overboard. It finally gave way to the point requiring replacement last week.
I have two new ideas. These are:
1. Install a vacuum pump and draw a vacuum on the crankcase in order to reduce the tendency to push oil out the front seal.
2. Install a vacuum pump and pull a vacuum on the space between the dual seals.
Thoughts about the vacuum ideas?
I've had people tell me that I needed to ground the plane and overhaul the engine immediately. BS! It's got great compression (topped 150 hrs ago) and is very powerful & smooth - but leaky.
There's something - probably to do with the crank seal surface prep + the high pressure oil from the CS prop - causing the problem. BTW - the sealing sfc under a lip seal needs to be as smooth as possible to work effectively. Mine's marginal.
Regardless, I am continuing to think about alternate seal configurations.
I just removed a dual (back-to-back) seal. Made with two seals and a gland to contain the outer seal. Had the space between the seals piped overboard. It finally gave way to the point requiring replacement last week.
I have two new ideas. These are:
1. Install a vacuum pump and draw a vacuum on the crankcase in order to reduce the tendency to push oil out the front seal.
2. Install a vacuum pump and pull a vacuum on the space between the dual seals.
Thoughts about the vacuum ideas?
Then read this......... http://www.lycoming.com/support/tips-advice/key-reprints/pdfs/Key Maintenance.pdf
GO TO PAGE 24 right side... Good Luck!
Warren
GO TO PAGE 24 right side... Good Luck!
Warren
