Easy Question for Mechanics... Please help

[BoosTT]

My haldex fluid drain plug (simular to a rear diff but with a clutch for an audi) got royally effed up. The treads for the drain plug are gone. I tried to drill the hole and retap, but the hole is very shallow and the tap can only go in a tiny bit, not enough to re-tap.

The vertical length is about 1.3 inches and the width is a 1/2 inch. The fluid is drained by removing the plug and then the fluid drips from the hole on the side of the plug. It is required every 20k miles, so I can't just seal it up. Heres a pic to help express what the problem is:

http://i256.photobucket.com/albums/hh166/jakejagmin/haldex.jpg


How can I plug this hole? Right now I have a rubber plug for a boat in there. So far so good, but I NEED something better. The part is $3500 alone, so I can't replace it for this stupid reason.

What can I do???

[HY35F2T]

is it possible could weld a bung to it with a screw on cap?

http://www.sjmautotechnik.com/trouble_shooting/suspension/trans_plug.jpgthat what your talking about?

[BoosTT]

Thats what I was starting to think. The problem is that I can't weld and it's in a pretty tight location under the car.

[HP ADDICT]

if its not a under pressure maybe jb weld a nut on it and the plug it with a short bolt?

[BoosTT]

I was actually thinking JB also. It's very low pressure (1 qt of fluid, no pump ~ has a filter though) with low heat (175 degrees f max).
I was worried about JB not filling in completely and leaking... do you think it would be ok?

[wikked]

If you're gonna JB it, that better be 1,000,000% dry and oil free when you do it, otherwise it will leak past.

Don't ask how I know :]

[HY35F2T]

I was actually thinking JB also. It's very low pressure (1 qt of fluid, no pump ~ has a filter though) with low heat (175 degrees f max).
I was worried about JB not filling in completely and leaking... do you think it would be ok?

me i would try to get it welded.

[88Nightmare]

x2 for welding. Find a place to weld a small bung on there with a short bolt for a plug.

[juicedimpss]

self tapping oversize drain plug?

[Moparjim]

The best solution is get a bung welded on. Two viable solutions that are not the best but will work and are not entirely hillbilly that I have used in the past are:

1) A nylon/plastic bolt of the appropriate size that you can jam in there and it will thread into the thinwall case. It should seal and be fine as long as it is tight enough, low heat enough. Buy a few of them as you may need to use a new one each time.

2) They make things for stripped oil pans. I don't know how to describe it but the best I could explain it is that it is like a rubber pacifier/plug, that come with a plastic tool that you push through the back, stretching the thing out lengthwise. This stretches the thing out so that it becomes smaller in diameter, you then insert it in there and pull the tool out. When you pull the tool out the thing shrinks back up lengthwise and expands a ton, plugging the hole. To remove it you use the tool again.

Though I am not proud of it, I have used both in a pinch before and both did indeed work.

[DurtyKurty]

This is a assuming the original plug is a regular flanged head plug with nylon/plastic gasket under the flange. Most drain plugs are.

So if that's the case, and if it's a .5" hole right now, drill it out to 9/16 and tap it for a 3/8-18 pipe plug. Put in a pipe plug of your choice. Done. Fixed forever, perfect seal, and still serviceable. 1.3" of depth is more then enough to tap that btw.

[DurtyKurty]

I gotta add that if it is a Flanged drain plug right now, there is no reason you can't heli-coil it either. That is actually the right way to do it.

[Russ Jerome]

Im a big fan of JB for minor repairs but not on oil, will
hold 30psi of boost but hot oil degrades the JB.

Even if you dont weld a bung on there I have welded
a heavier peice of metal on steel and aluminum pans
and then drilled and tapped for a plug.

If you weld a bung or nut on the thin metal use a
flanged nut so you dont have to overheat the
thinner metal welding the thick nut.

I've seen rubber expansion plugs like you are using on
cars that have worked for YEARS without leaking. Hell
look an old Studabaker or Chevy, had them brand new!

[BoosTT]

I really want to just tap it, but the taps i've seen are about 3 inches long and a cone shape. You have to stick them in atleast two inches to really put some threads in. Is there a different type of tap?

The self tapping plug sounds awesome, but I can't find them anywhere online. Where did you see them?

Welding is a last resort for me (but I do agree is the best). I can't weld, don't know anyone who can weld, and really don't want to drive the car without oil in there to someone who can.

[fly5150]

you need a bottoming tap. Fastenal has them, some hardware stores do.

[BadAzzGTA89]

you need a bottoming tap. Fastenal has them, some hardware stores do.

Yup!!
http://www.muller.net/mullermachine/howto/insert/taps.jpg

[BoosTT]

Thats perfect. Thanks for the help guys!!