Rear diff fill plug? NPT plug?

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thinger2

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Mine was tore up. It's just a plumbing part right? NPT threads?
Always start with year, model, engine etc.
We need to know what you are working on before anything happens.
And, just for anyone else who might read this though it doesnt really apply to a chevy diff.
If you ever encounter a drain plug, fill plug situation.
Always Always pull the fill plug first.
There is nothing worse than draining all of the oil out and finding that the fill plug is stuck or stripped.
just remember...
Fill plug first drain plug last
 

Schurkey

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Mine was tore up. It's just a plumbing part right? NPT threads?
Rear axle? Almost certainly NPT. I like brass if I have to buy new plugs.

OTOH, the transfer case in my '97 K2500 uses METRIC tapered pipe thread. Had to go to the Stealership to get a proper replacement.

I won't make any promises on GM using standard or metric threads any more. They've already paid the engineers, so they figure they might as well have them change some stuff.
 

RichLo

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If you have a few GM RWD vehicles, it might be handy to buy 2 or 3 to have a spare on hand when the next one give you trouble. I like replacing them with the large external square that you can get an open-end wrench on. Those internal 3/8 squares always seem to strip out.
 

someotherguy

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If you have a few GM RWD vehicles, it might be handy to buy 2 or 3 to have a spare on hand when the next one give you trouble. I like replacing them with the large external square that you can get an open-end wrench on. Those internal 3/8 squares always seem to strip out.
I had trouble with those stripping when I'd use a 3/8" extension as the removal tool. Then I bought some legit square sockets and they fit way better.

My "go to" method for getting really stuck ones loose in the past was to persuade them with a chisel. A couple hits across the edge in a counter-clockwise direction often got them moving, then able to remove with less brutal tools.

Richard
 

Schurkey

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For ****'s sake, do not EVER remove a square-recess plug with a socket extension.

Some plugs may have a 1/4", 3/8", 1/2" or 3/4" square recess, but don't use an extension or even a ratchet or breaker-bar square-drive to turn 'em.

Extensions, especially are very weak at the point where they're drilled for the socket-retention ball and spring. It is VERY easy to twist them off at that drilling. Not only does this ruin your tool, but the broken tip is likely going to be stuck in the square recess of the plug.

Use plug-removal sockets that are not drilled for socket retention balls 'n' springs. They're commercially available from multiple suppliers at varying prices (like everything else.)
 

someotherguy

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For ****'s sake, do not EVER remove a square-recess plug with a socket extension.

Some plugs may have a 1/4", 3/8", 1/2" or 3/4" square recess, but don't use an extension or even a ratchet or breaker-bar square-drive to turn 'em.

Extensions, especially are very weak at the point where they're drilled for the socket-retention ball and spring. It is VERY easy to twist them off at that drilling. Not only does this ruin your tool, but the broken tip is likely going to be stuck in the square recess of the plug.

Use plug-removal sockets that are not drilled for socket retention balls 'n' springs. They're commercially available from multiple suppliers at varying prices (like everything else.)
We were young, inexperienced, and there wasn't any internet to ask folks what was what. We made mistakes, learned, and bought correct tools. It's OK now. :)

Richard
 

Schurkey

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We were young, inexperienced, and there wasn't any internet to ask folks what was what. We made mistakes, learned, and bought correct tools. It's OK now. :)
It's OK for YOU. You had the intellect to learn, and the motivation and sense to buy the proper tools.

There's a huge number of OTHER young, and/or inexperienced folks who need to hear this.

I dealt with this over and over at The Bus Plant. Part of our job was to remove pipe-thread plugs from Detroit Diesels that were installed with thread-locking sealant. The plugs were square-recess stuff requiring male square-drive tools to remove. The plant was hiring doofuses who didn't own tools until the State bought them the minimum Company Mandatory Tool List of cheap junk tools and a lil' red carry-around box to hold 'em in. Invariably they would ignore me, and cram their Made-In-Asia 3/8 extension into the plug recess, and then have to admit to me that the tip broke off. It was practically a rite-of-passage there.

Don't get me started on crappy open-end wrenches that spread like a pros_titute when used to remove Detroit Diesel fuel fittings.
 
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