help, stripped threads on oil drain plug

[Jaybird]

You really don't need to explain yourself. It really aint that big of a deal.

But, since you are of the club that can turn and mill, of which I think you will find a good deal of company here, I want to ask you this. Non-confrontational, just trying to make a point...

You have a balloon filled with air. You pinch off part and make a small hole.

You can let out half of the air by gently letting the rubber go where the hole is, but being careful to stop it at about the half way point OK...with me?...you have a good control of this release of air. Now, I want you to estimate how much talcum powder you can stuff into the hole that you are allowing the air to escape from before it is half empty. Give it a good go and stuff as much as you can.

 

[Rice#67]

Now, I agree this will work... but in order to pressurize the crankcase what did anybody use to seal the top of the crankcase? Because without totally sealing it I see where robbie is coming from... then your just blowing air around and not pressurizing, and I think this is where the confusion lies...

 

[Jaybird]

It doesn't have to be sealed.

 

[robbieisurfriend]

3 ounces of Gold Bond Medicated. :nener:
My point, err, addition, was just that chips fly when hit with compressed air. You might be 100 percent correct that you could blow a huge stream of air into the case and it would pressurize it and not blow things around. I guess if u pressurized it first before tapping it couldn't make them fly around. I just pictured somebody in their garage tapping the hole, half way in and then blowing compressed air into the fill hole which I would guess would blow chips around but I am just that, guessing. Sorry if I did not make that clear before. I was not trying to say anybodys logic was wrong.

 

[Ol'89r]

No worries Rob.

We all learn from each other here. I have been in this business since 1964 and I'm still learning every day.

It is not necessary to seal the gearbox. You only need about 20 PSI to do the job. When you add air to the filler hole, air will escape from the drain hole and the breather tube. You can seal the breather tube but it is not necessary. As you tap the drain hole the chips will be blown directly out of the drain hole. They never have a chance to enter the pressurized gearbox.

Adding grease to the tap will insure that any loose chips will stick to the grease and by removing the tap several times and re-greasing it while tapping you can be assured that no chips have entered the gearbox.

Aluminum chips can indeed cause damage to bearings and seals and you should take great care to keep them out of your gearbox.

This method also works very well when welding up, re-drilling and tapping a drain hole.

Try it, you might be supprised. :cool:

 

[truespode]

One concern I would have about the compressed air is the condensation that occurs in the tank that a lot of people do not deal with.

I wonder if the amount of moisture would be problem? Or would a simple flush take care of that pretty easily?

Ivan

 

[Ol'89r]

Ivan.

Condensation would not be a problem. For the amount of air introduced to the gearbox there wouldn't be enough condensation to worry about even if you didn't drain your compressor. When oil is added to the gearbox, that would take care of any moisture.

 

[Jaybird]

I agree that it would not be a big problem normally. But, even when you tank is drained and dry, the water is still coming. Any moisture in the air is transmitted to the end of the air nozzle at about a 8:1 ratio. This means you are introducing 8 times the amount of moisture into the case that would have been there.
I also think that the bit of moisture that enters from this is not going to be a problem, especially if the engine will be run soon.
But the moisture and dirt are there, and immediate. Just hold your air nozzle close in front of a mirror while releasing the air full force for a few seconds. Now take a look at your mirror.

I am always concerned about the moisture, rust, and hydrocarbon content of compressed air, so my compressor is rigged up with a coalescing filtration system that provides me clean, dry air anytime I need it. It also automatically drains the tank.

Folks who do not have adequate filtration on their compressor (probably 99.9% of private compressor owners, and 90% of industrial ((believe it or not)), are going to be introducing iron oxide into their engine case. I guarantee this because your compressor tank is full of the stuff, and it sends it downstream whenever you release any air.

I didn't mean to open a can of worms here...but Ivan's worries are not quite as unfounded as one may think.

 

[Rotorranch]

I also know that whoever said that they would not use oil has never broken off a tap in an expensive part.

IF I were doing it this way, I might not grease the tap, thus allowing the chips to blow out the flutes a little easier, instead of sticking.

Note I did not say cutting oil, I said grease. And I haven't broken a tap since before you were born! :) ( Knock on wood! )

Rotor