51 year old prop governor?

[N201MKTurbo]

A long time ago in a galaxy far far away, some hangar fairies went to a prop shop and bought a new gasket for $2.00. They disassembled the governor and replaced the gasket.

Everybody lived happily ever after!

[ShermAv8tor]

I just did mine and its a tight space on a 65 C, you have the gasket between the engine and the accessory mount (what the governor is mounted to), and then you have the gasket between the mount and the governor, both of mine were leaking. The gasket between the mount and governor (2nd gasket going aft from engine block) actually has a built in screen to filter oil going into governor, and needs to face correct way when reinstalled (gasket was 22 bucks due to built in screen) If its either of these 2 gaskets, its worth trying to replace them since the governor is not failed, plus the inspection of the screen will reveal if its been clean or possibly crud trying to get in, mine was squeaky clean and its the original governor. I would also check to see if Quality Aircraft Accessories services or overhauls these governors (or might know who does) before I took the word of some prop shop about just scrapping it without even looking at it........

[jetdriven]

1 hour ago, ShermAv8tor said:

I just did mine and its a tight space on a 65 C, you have the gasket between the engine and the accessory mount (what the governor is mounted to), and then you have the gasket between the mount and the governor, both of mine were leaking. The gasket between the mount and governor (2nd gasket going aft from engine block) actually has a built in screen to filter oil going into governor, and needs to face correct way when reinstalled (gasket was 22 bucks due to built in screen) If its either of these 2 gaskets, its worth trying to replace them since the governor is not failed, plus the inspection of the screen will reveal if its been clean or possibly crud trying to get in, mine was squeaky clean and its the original governor. I would also check to see if Quality Aircraft Accessories services or overhauls these governors (or might know who does) before I took the word of some prop shop about just scrapping it without even looking at it........

AQI offered to overhaul mine but since I was changing model numbers, the hard parts were going to be north of 500$ plus the 700$ overhaul, thankfully they just exchanged it for 1100$.  but even if it was a straight overhaul the governor mfr puts out service letters that they have to comply with since they are a repair station, which means a 300$ set of flyweights and a 400$ control valve, plus the overhaul cost, it quickly exceeds 2 grand.

[N601RX]

2 hours ago, N201MKTurbo said:

A long time ago in a galaxy far far away, some hangar fairies went to a prop shop and bought a new gasket for $2.00. They disassembled the governor and replaced the gasket.

Everybody lived happily ever after!

For tractor repair and such McMaster also has a CNC gasket cutting service for any of the gasket material that they sell. All they need is a CAD file.

If it's an H1 governor it doesn't use a gasket in the gear pump section, it just uses a sealent much like the case halves do.  There is a large gasket around the flyweight section on the rear.  

[carusoam]

Message for Ross.

Crankshaft seal at the prop end...

The prop is bolted to the end of the shaft.  That end of the shaft is bored all the way through.  Oil from the gov enters through the plumbing on the side of the shaft through the side of the motor(?).  Oil hose at the front of the engine

The other end of that bore is closed off with a circle of aluminum.  Hammered into place.

When/if this seal moves about, the pressurized gov oil leaks back into the engine and drains into the sump.  No issue here.  Just not visible.

Is there an easy way to measure the pressure at the exit of the gov? 

The logic at the time was OH the govenor first. Followed by pulling the prop next.  The fly weights were well worn so the OH was needed.  The problem was the shaft need to be reset.  I believe a new one was put in place.

My descriptions technically are not very good.  They are coming from memory that isn't very strong.  Let me know if there are any questions.  I'll try to clear anything up.

Best regards,

-a-

[Shadrach]

5 hours ago, carusoam said:

Message for Ross.

Crankshaft seal at the prop end...

The prop is bolted to the end of the shaft.  That end of the shaft is bored all the way through.  Oil from the gov enters through the plumbing on the side of the shaft through the side of the motor(?).  Oil hose at the front of the engine

The other end of that bore is closed off with a circle of aluminum.  Hammered into place.

When/if this seal moves about, the pressurized gov oil leaks back into the engine and drains into the sump.  No issue here.  Just not visible.

Is there an easy way to measure the pressure at the exit of the gov? 

The logic at the time was OH the govenor first. Followed by pulling the prop next.  The fly weights were well worn so the OH was needed.  The problem was the shaft need to be reset.  I believe a new one was put in place.

My descriptions technically are not very good.  They are coming from memory that isn't very strong.  Let me know if there are any questions.  I'll try to clear anything up.

Best regards,

-a-

I am familiar with the crank flange area (I have R&R'd my prop under supervision numerous times for various reasons) but far from an expert. I'm still not sure which which seal your referring to. Are you suggestion that the back side of the crank has a plug in it similar to the plugs used to seal the front of the crank on fixed pitch applications? I did not know this. When yours failed did you have to split the case to fix it?

[N601RX]

Yes there is both a front and rear plug in the front section of the hollow cranks.  For a fixed pitch prop you install the front plug and remove or puncture the rear plug.  For a constant speed prop only the rear one is installed.  If the rear one comes out on a constant speed you loose the governor function. It can be installed with the prop removed.

[N201MKTurbo]

The H1 governor has a small square o-ring in the gear pump section.

Back in the eighties I was told that the correct o-ring was no longer available and to use a slightly bigger o-ring and cut it down and splice the ends with sealant.

It worked fine. Same issue in the late 90s and I was able to get the correct o-ring. I have an overhaul manual at the hangar, I could look up the part number of the o-ring.

[carusoam]

Ross, I think Mike (601RX) described it much better than I did.  That metal seal is replaced from the front of the shaft.

I believe it is a press fit and only has a rare chance of falling out of place.  

Best regards,

-a-

[Yetti]

On 11/29/2015, 9:11:13, N601RX said:

For tractor repair and such McMaster also has a CNC gasket cutting service for any of the gasket material that they sell. All they need is a CAD file.

Sheet of gasket material and a small ball peen hammer...Set of hole punches  If you are in a pinch. sometimes works better than the fancy machine cut

[Shadrach]

1 hour ago, Yetti said:

Sheet of gasket material and a small ball peen hammer...Set of hole punches  If you are in a pinch. sometimes works better than the fancy machine cut

This is the method I used to seal the primary case on my old Triumph twin. Gasket material = brown paper grocery bag.

[carl]

On 5/5/2015 at 10:12 PM, stevebennett327 said:

   I recently purchased a 64 e model. It was only flown 8 hours in the last 20 months before my purchase. I have flown it 40 hours in 3 months since buying it and it has taken on some oil leaks. It's had several trips to the mechanic then I fly it and a few more things start leaking. It started leaking heavily after a 3 hour cross country flight to Atlanta. It was dumping a quart an hour. I just had the prop governor removed and the gasket replaced and it got a little better. The mechanic said that he tightened slightly the bolts on the gov and that it might be leaking from a seal that he can't change. I called a prop shop today and they suggest just scrapping the old governor without even bench testing it. I said it works fine it just leaks oil. I've ordered a new governor but while I was ordering I said to myself that I was going to post my problem here and see if other members here think I did the right thing.  Ok, let me have it. I spent 1764 dollars on a new one before install. Steve Bennett 1964 M20E

I just bought a new governor too. For my 1967 20 E.  Sensenich propeller said they can rebuild this, it's junk! Oh well .I'll call that my Christmas gift to myself.

carl