9 inch drain plug

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Mar 30, 2012 | 10:13 PM

#16

Gary Lewis

FTE Legend

Joined: Jul 2010

Posts: 32,875

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From: Northeast, OK

Quote:

Originally Posted by Rivergreen74

Thanks, how thick is the actual metal at the bottom of the casing? I plan just to drill and tap in a NPT 3/8 magnetized plug.x

I don't remember how thick it is, but I'm pretty sure I reported on that in my 8-page micro-****-ysis. I've heard you can get by tapping it and getting a bolt to hold, but I wouldn't use a pipe plug. Instead I would use a drain plug that has a flange and gasket. A pipe plug seals due to the tapered threads, both of the plug and the fitting into which it threads. But in this case you'll have about one turn of thread and the chances of that sealing aren't good. On the other hand, a drain plug isn't using the threads to seal, but instead uses the gasket material and that is independent of the number of threads.

Mar 31, 2012 | 05:01 AM

#17

Poison Oil Racing

Posting Guru

Joined: Nov 2007

Posts: 1,305

Likes: 2

From: Montgomery, IL

Quote:

Originally Posted by Rivergreen74

Thanks, how thick is the actual metal at the bottom of the casing? I plan just to drill and tap in a NPT 3/8 magnetized plug.x

It is probably close to 1/2 in thick. Maybe more. I don't remember the size hole I drilled but I got an oil pan drain plug from Auto Zone ( I think you can get magnetized ones too) and used that. Drilled the hole based on the size of the plug. The plug has a gasket on it so it doesn't leak like a pipe plug would (see Gary's comments above).

Apr 2, 2012 | 12:42 PM

#18

ChaseTruck754

Lead Driver

Joined: May 2007

Posts: 6,993

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From: Costa Mesa, CA

Quote:

Originally Posted by Gary Lewis

...but I wouldn't use a pipe plug. Instead I would use a drain plug that has a flange and gasket. A pipe plug seals due to the tapered threads, both of the plug and the fitting into which it threads. But in this case you'll have about one turn of thread and the chances of that sealing aren't good.

Use a threaded bung welded to the housing for the pipe plug like I said.

I guess this is like "would you prefer chocolate or vanilla" though - everybody has their own way.

I'm not a huge fan of dealing with gaskets or the copper washers that come with the typical drain plugs.

Apr 2, 2012 | 11:14 PM

#19

piperig78

Senior User

Joined: Nov 2004

Posts: 240

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From: Appleton, WI

This is tip i was told but never tried, but seems to be the simplest. Take the bottom stud out that holds the third member in. (by double nutting it) and the oil should drain out. Replace with bolt and copper washer if you plan to do it often. otherwise just put back together as it was.

Apr 3, 2012 | 09:44 PM

#20

Rivergreen74

Thread Starter

Junior User

Joined: Dec 2011

Posts: 97

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From: Alberta, Canada

Update- I drilled the hole just to the right of centre on the bottom of the differential and found the casing to be approximately 1/4 inch thick. I was going to use a NPT 3/8 plug but was unsure if it would seal with 2-3 threads, I ended up using a 1/2 inch fine thread oil plug with a gasket. Sealed up no problem and all is good.

Thanks all.