Author Topic: 12 bolt rear end fluid capacity  (Read 3780 times)

Offline Sprinkler-Man

  • Newbie
  • Posts: 76
  • 80 GMC Sierra Classic 4x4
12 bolt rear end fluid capacity
« on: June 07, 2019, 07:18:24 PM »
I can’t get my fill plug out but there is a breather vent on the top I can access and fill from. I have been reading to go with 2 quarts but wanted to confirm with the forum.


Sent from my iPhone using Tapatalk

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 18980
Re: 12 bolt rear end fluid capacity
« Reply #1 on: June 07, 2019, 08:36:58 PM »
Good luck with that. Extract the fill plug and save yourself some aggravation. Is it stripped, what's the problem?
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Sprinkler-Man

  • Newbie
  • Posts: 76
  • 80 GMC Sierra Classic 4x4
Re: 12 bolt rear end fluid capacity
« Reply #2 on: June 07, 2019, 08:49:25 PM »
Yes it’s striped. Unfortunately, I don’t have a welder to weld a bolt to it.  I pulled off the breather cap and can blow down through the vent, but this was with the differential cover off. Why do you see a problem? 


Sent from my iPhone using Tapatalk

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 12 bolt rear end fluid capacity
« Reply #3 on: June 07, 2019, 10:33:39 PM »
have to get vile of one of those to confirm but one thing i know you might be able to do is put the right amount of oil in a ziplock and toss it in the differential.
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: 12 bolt rear end fluid capacity
« Reply #4 on: June 08, 2019, 12:22:37 AM »
have to get vile of one of those to confirm but one thing i know you might be able to do is put the right amount of oil in a ziplock and toss it in the differential.

What??
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 12 bolt rear end fluid capacity
« Reply #5 on: June 08, 2019, 03:04:17 PM »
i remember seeing on tv a few years ago someone rebuilding a read end. when they filled it they just filled a zip lock full of gear oil and tossed it in. they said the zip lock would break down and it will be ok. but i dont recall what style differential it had. so if they worked on something like a Detroit locker, i dont know if you can do the same for lets say a gov locker
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Sprinkler-Man

  • Newbie
  • Posts: 76
  • 80 GMC Sierra Classic 4x4
Re: 12 bolt rear end fluid capacity
« Reply #6 on: June 08, 2019, 03:44:54 PM »
I pulled the vent and put in two quarts. Took me about 15min to do. Now I can take it to a shop to get a bolt welded into the plug to get it out and replace it.


Sent from my iPhone using Tapatalk

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 18980
Re: 12 bolt rear end fluid capacity
« Reply #7 on: June 09, 2019, 11:50:30 AM »
have to get vile of one of those to confirm but one thing i know you might be able to do is put the right amount of oil in a ziplock and toss it in the differential.

What??

LMAO

Use this: http://www.ctatools.com/index.php?route=product/product&path=59&product_id=150
,                           ___ 
                         /  _ _ _\_
              ⌠¯¯¯¯¯'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: 12 bolt rear end fluid capacity
« Reply #8 on: June 09, 2019, 12:29:46 PM »
i remember seeing on tv a few years ago someone rebuilding a read end. when they filled it they just filled a zip lock full of gear oil and tossed it in. they said the zip lock would break down and it will be ok. but i dont recall what style differential it had. so if they worked on something like a Detroit locker, i dont know if you can do the same for lets say a gov locker

Why would anybody entertain, let alone recommend, using something that belongs in the county dump to put "clean oil" in a differential?  But then, if it was on TV or UBoob, it must be true....
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 12 bolt rear end fluid capacity
« Reply #9 on: June 09, 2019, 03:27:37 PM »
its true lol thats kind of why i wanted one of you two to confirm what i saw. glad we got that all cleared up now, but for real i remember them tossing it into the rear then sealing it up and saying something like the gears will break it down in no time
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2526
  • Old Goof
Re: 12 bolt rear end fluid capacity
« Reply #10 on: June 10, 2019, 09:42:18 PM »
OMG

Was it from the '70s or some other mislead era? HeeHaw?
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 12 bolt rear end fluid capacity
« Reply #11 on: June 13, 2019, 08:20:28 AM »
it was one of those shows on power block or something like that, believe back around 2010.
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline JohnnyPopper

  • Senior Member
  • ****
  • Posts: 2526
  • Old Goof
Re: 12 bolt rear end fluid capacity
« Reply #12 on: June 13, 2019, 01:11:31 PM »
Well, plastic is a byproduct of oil, so in theory it will return to 'natural state'...
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Irish_Alley

  • Tim
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13319
  • Family is not an important thing. It's everything.
Re: 12 bolt rear end fluid capacity
« Reply #13 on: June 13, 2019, 02:24:26 PM »
that was my thinking also and why it made sense. but i wasnt sure if somehow it would mess up the clutches on some model rear ends
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: 12 bolt rear end fluid capacity
« Reply #14 on: June 13, 2019, 03:24:46 PM »
Give it a rest.  Nothing about it makes sense.  It is poor practice!
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)