replacing the front crank seal

[robbie]

Got the plane annual this week, got a couple gigs to take care of and need to replace the crank seal. My AP is gone till next week and said," get the seal out and will install new seal when I gets back."
How do you pull it out,been in there for almost 20 years.
I'm about ready to pound the **** out of it.
OK lets hear from the pros.

[Mark Julicher]

Re: replacing the front crank seal

Robbie,
Take your time and don't scratch the bore where the seal goes.

Assuming this is a flanged crankshaft proceed as follows:
Remove the prop.
Go to Aircraft Lowe's Depot NAPA Autozone, and purchase a cotter pin puller tool often called a "booger picker."
Use the booger picker to carefully puncture the front face of the rubber seal and slowly tease the seal out of the bore. If you tear it a little that's fine, just keep working at it. Once you have it partially out, a long regular screwdriver can also be used to carefully work the old seal out. Once the seal is out, use MEK on cotton swabs to clean the bore. It should be as clean as a cat's whisker before the new seal goes in.

The procedure is easier for a taper shaft but you must first pull the propeller adapter off. refer to earlier postings via the search feature to see how to do that.

[robbie]

Re: replacing the front crank seal

I forgot to say, it's a taper shaft and the prop and hub is off.
The seal is a continual seal with
the metal side out .

[Mark Julicher]

Re: replacing the front crank seal

Taper shaft seal is simple enough. It was tapped into place with a leather mallet or similar pounding device, so it will tap out also.

Just drill one or two 1/8 holes through the metal face of the seal so you can hook a pick onto the seal. It is thin metal, so use a drill stop or even masking tape wrapped around the drill bit to allow only a small penetration-- no more than 3/16 of drill bit should poke through the hole you drill.

If you have a slide hammer you could use that, but a 90 degree pick and little effort and gentle persuasion should be enough to work the seal out. If you went out and got a cotter pin puller try using that as a pulling tool.

The seal will deform as you pull on it making it easier to get a grip and/or pry it out; however, don't grab a big honking screwdriver and pry like crazy or you may damage the bore. Take it easy. If the original gasket cement is hardened and impeding progress you could try a few drops of MEK to help, but don't use very much.

[robbie]

Re: replacing the front crank seal

I can get a taper pin puller which have a #8 screw welded on the screw.
Maybe that will work.

[Mark Julicher]

Re: replacing the front crank seal

That should work.
Go for it.

[robbie]

Re: replacing the front crank seal

Seal out and new one in.
What we did was install new one but did not seat it all the way in.
The old one was about 1/16" inside of the case.
We installed new one maybe 1/16" out side the case.
Flew about an hour yesterday, and all looks good.
Will continue to monitor the seal for the next 2 or 3 hours.