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Rear differential fill plug

Aaron, not A-A-Ron
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Aaron, not A-A-Ron Enthusiast

Aaron, not A-A-Ron

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I'm trying to replace the fluid in the rear differential of my 2003 suburban.  Before I started removing the cover I tried to get the fill plug off first.  Of course it stripped, even after scraping the rust and using lots of PB Blaster.  I eventually got it out, but now I could really use a replacement fill plug.  Does anyone have the part number or know of a plug that will fit?  This seems to be a common problem, but I can't find the part anywhere online.  I guess I could reuse the rounded plug...one last time...

txab Senior Enthusiast

txab

Posted
Posted

I've seen them on Rockauto before. Any local auto parts store will have them for sure

Aaron, not A-A-Ron Enthusiast

Aaron, not A-A-Ron

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Cant find it, specifically, on Rock Auto.  Just the drain plug for ones equipped with one, mine isn't.  Unless the drain and fill plugs are the same size, they certainly dont look the same.  The drain plug has the hex head, and the fill plug has the recessed 3/8" socket head

garagerog Enthusiast

garagerog

Posted
Posted

Aaron, not for sure on yours, but on at least the older GM differentials the fill plug was NPT, 3/4" was a common size. You could try and match it up at any hardware store, the recessed plug style may be hard to find, most NPT plugs have a square head.

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garagerog Enthusiast

garagerog

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36 minutes ago, Aaron, not A-A-Ron said:

garagerog, Would I have to worry screwing it in to far?  I wouldn't think so, but making assumptions was worked out so well for me...:)

Shouldn't be a problem, a little anti-seize dope on the threads should make removal the next time much easier.

txab Senior Enthusiast

txab

Posted
Posted
3 hours ago, Aaron, not A-A-Ron said:

Advance, Auto Zone, and AC delco websites were no help either.

If you're trying to find them through their website, you're probably wasting your time. Go to the store. They should have the in the "HELP" line. I've gotten them there and NAPA before with no issues. Or as mentioned just match it up at the hardware store. Square head isn't a problem

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Aaron, not A-A-Ron Enthusiast

Aaron, not A-A-Ron

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Thanks for the 'HELP' suggestion!  Forgot about that one.  With Covid, going to stores in suburbia can be challenging.  Better grab my mask.

28 minutes ago, txab said:

If you're trying to find them through their website, you're probably wasting your time. Go to the store. They should have the in the "HELP" line. I've gotten them there and NAPA before with no issues. Or as mentioned just match it up at the hardware store. Square head isn't a problem

 

Z45 Senior Enthusiast

Z45

Posted
Posted (edited)

I has been said several times. These are just standard pipe plugs and nothing special.  Any well stocked hardware store should have them.

 

Finding them at GM parts look-ups can be difficult because won't be listed in a regular parts guide. Fasteners etc are what are referred to as standard parts.  I dare say that AC Delco shown probably fits all from the 1950's up. 

Edited by elcamino
BlaineBug Enthusiast

BlaineBug

Posted
Posted (edited)
2 hours ago, elcamino said:

I has been said several times. These are just standard pipe plugs and nothing special.  Any well stocked hardware store should have them.

 

Finding them at GM parts look-ups can be difficult because won't be listed in a regular parts guide. Fasteners etc are what are referred to as standard parts.  I dare say that AC Delco shown probably fits all from the 1950's up. 

They do have a magnet on them I believe.  The fill plug for the rear differential in my 2019 does at the very least (no drain plug as you're supposed to remove the cover.)  The front differential also has a magnet on the drain plug, but not on the fill plug, since the front differential has 2 plugs.

If you want to know for sure, the dealer may be your best bet.  I can't imagine it costs more than $15.

Edited by BlaineBug
newdude Senior Enthusiast

newdude

Posted
Posted
19 hours ago, Aaron, not A-A-Ron said:

I'm trying to replace the fluid in the rear differential of my 2003 suburban.  Before I started removing the cover I tried to get the fill plug off first.  Of course it stripped, even after scraping the rust and using lots of PB Blaster.  I eventually got it out, but now I could really use a replacement fill plug.  Does anyone have the part number or know of a plug that will fit?  This seems to be a common problem, but I can't find the part anywhere online.  I guess I could reuse the rounded plug...one last time...

 

For a 1500 Suburban, GM# 444788.  1/2-14 thread, 39/64" long.  

 

For a 2500 Suburban with the 6.0 and 9.5" axle, GM# 93439312.  1/2-14 thread, 39/64" long.  

 

For a 2500 Suburban with the 8.1 and 10.5" axle, GM# 93439312.  1/2-14 thread, 39/64" long.  

 

Quadrasteer fill plug is discontinued, no specs on size/threads provided from GM.  

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