force one prop hub seal leaking

[vmcurry]

is it possible to replace seal without disassembling engine.

 

[eschrom]

You have to pull the hub off to do that and yes it can be done without disturbing the engine. You'll need a puller and probably a little heat.

 

[JondorB1]

vmcurry, are you sure the seal is leaking? I had oil leaking from the prop hub seal when my breather hose was too restrictive; once I increased the ID of the hose, I didn't have any more oil bypassing the hub seal.

 

[Pops]

I had a small leak around the prop hub seal. Tried different places to place the end of the vent tube is a low pressure area. Finally did what VW did on the type 1 engine in the bug. Ran the vent tube into the side of the tube between the air filter and the intake of the carb. Blue hose at each end of the aluminum vent tube. No leak.

 

[vmcurry]

I appreciate the input, will try the breather hose fix.

 

[Hove]

Please let us know if it takes care of your leak.

 

[Speed20]

You have to pull the hub off to do that and yes it can be done without disturbing the engine. You'll need a puller and probably a little heat.

Two years ago I changed my seal. After removing prop I raised tail onto a sawhorse. I took a 2x4 and bolted it to the prop flange and the other end contacted the floor. After pulling the big cotter key out I was then able to break the big retaining bolt loose and just tapped the hub off the crank with a plastic mallet

 

[eschrom]

Mine wasn't so easy. After removing the holding bolt and cotter pin I applied a homemade puller that tugged on the hub while bearing against the shaft and even then I had to warm the hub with a torch before it popped off.

 

[vmcurry]

Breather to intake did not fix leak, does make for shorter run tube. Mine is 1/2 tubing, was over the top of case through firewall down and exit at back of gear leg. Terminated in elbow pointing aft near wheel. Tried to order seals, but Great plains needs to know if 1 or 2 seal type. I'm not original owner so must tear down to find out

 

[Chucker]

Millions of Beetles scurried around the world for decades with no leakage between the crankshaft and pulley...and they had no seal whatsoever. The only thing keeping the oil inside was the slinger and a cavity to catch the slung oil and return it to the sump. There is one other difference to consider. You have pressurized oil fed to the Force One Bearing. I have never owned (or seen) the Force One design but I did own a Revmaster. The Revmaster had a means of returning the oil from the bearing to the case. If that return becomes plugged the seal may not be able to contain the pressure and may leak.

Just throwing stuff at the wall to see what sticks...and trying to save a teardown.

 

[Pops]

And the million of Beetles had the crankcase vented to the oil bath air cleaner for the low pressure . I did the same on my engine and stopped any oil leak around the prop hub.

Aluminum tube to the blue hose to the intake in front of the Zenith carb.

 

[Chucker]

And the million of Beetles had the crankcase vented to the oil bath air cleaner for the low pressure . I did the same on my engine and stopped any oil leak around the prop hub.

Aluminum tube to the blue hose to the intake in front of the Zenith carb.

Sounds as though he already tried that...without success.

 

[vmcurry]

I appreciate all of the input, gives a heads up to look at pressure area between seals for outflow. I will be able to pull seals after pulling hub, without having to separate case halves. Waiting for seals from Greatplains before I pull hub. Thanks again to everyone

 

[vmcurry]

I would like to see examples of homemade pullers for force one hub. I have prop off and new seals. not sure how to fabricate puller.

 

[eschrom]

Mine is a 1" thick plate with a tapped hole and bolt in the middle. There is also a hole circle that matches the one in the hub. Place a thick washer or piece of bar stock at the end of the shaft for the bolt to bear against and attach the puller to the hub with six 5/16" bolts and nuts, finger tight. Apply never-seez to the big bolt and turn it to pull the hub. You'll need a way to grip the plate to counteract the torque - that's what the two tapped holes on the edge are for. Somewhere in my basement is a handle that attaches there.

If the hub doesn't pop off try some heat while the puller is pulling but don't go crazy, just get the hub warm. You could also try Aero-kroil or one of those. As I recall it took some patience but the hub did eventually yield to my wishes. A folded blanket to catch it wouldn't be a bad idea.

Ed

 

[vmcurry]

Thanks for the picture, Eschrom. I was able to duplicate. Worked great. Hub off, seals replaced, hub back on. Prop and cowling today or tomorrow, I hope then test fly for leak.

 

[eschrom]

Glad to hear it worked. The Great Plains assembly manual says torque for the hub bolt is 70 lb-ft, in case you didn't already know. Good luck with your leak.

 

[vmcurry]

Test flew today. same leak with new seals. Seemed to be more wear on hub where seals ride than hours would justify. I bought, didn't build this airplane. maybe hub from another engine. I guess a new hub might be only solution. I took a few thousandths off trying to smooth it out. I purchased a Great Plains assembly manual before beginning, mine says 50 to 60 ft/lbs to line up cotter pin hub and bolt holes. mine lined up at 50 so i pinned it there. hope thats enough. Couldnt find prop bolt torque anywhere, called A/P that sold his sonerai 2 years ago, he suggested 14 ft/lbs. A champ here at the airport with wood prop only shows 7 ft/lbs

 

[Chucker]

Go to GPASC. They have instructions for prop installation with proper torque.

 

[Pops]

Many years ago I called Steve at GP's and wanted to order a new prop seal form my GP's shrunk on prop hub. He told me to just go down to the local auto parts store and buy a National Seal #6815. Its a wheel seal for a dozen or so makes of autos. Not long ago they were on sale and I ordered a life time supply from Rock Auto on line for $0.53 each.