The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-04-2013, 03:20 PM   #1
mark be
Registered User
 
Join Date: Aug 2003
Location: oregon
Posts: 54
12 bolt question

Can someone explain what I'm looking at here? I don't see this mechanism in any exploded views.
The ring gear has 34 teeth and turning the wheel 2 turns gets about a 3:40:1 ratio, it's in a '70s c10 2 wheel drive.
Attached Images
  
mark be is offline   Reply With Quote
Old 03-04-2013, 03:33 PM   #2
silvereagle07
Registered User
 
silvereagle07's Avatar
 
Join Date: Sep 2008
Location: Bailey, NC
Posts: 2,462
Re: 12 bolt question

It's an Eaton factory posi locker carrier.
__________________
Jeramy

'84 GMC project truck
'85 Chevy 4X4 SOLD
'07 Chevy Trailblazer SS

5th Annual SHPHC Car/Truck Show Pics
http://67-72chevytrucks.com/vboard/s...d.php?t=543605 UPDATED PICS! CHECK 'EM OUT
silvereagle07 is offline   Reply With Quote
Old 03-04-2013, 03:56 PM   #3
mark be
Registered User
 
Join Date: Aug 2003
Location: oregon
Posts: 54
Re: 12 bolt question

Where are the clutches?

I found these #s on the ring gear
6270998 10:34 GM 9 782

Can't find the 3:40 ratio listed anywhere, this is all new to me so please excuse my ignorance.
mark be is offline   Reply With Quote
Old 03-04-2013, 05:02 PM   #4
mark be
Registered User
 
Join Date: Aug 2003
Location: oregon
Posts: 54
Re: 12 bolt question

I should have posted in "engine and drive train" If a mod can move would be grateful
ThanksMark
mark be is offline   Reply With Quote
Old 03-04-2013, 05:33 PM   #5
83GMCK2500
Registered User
 
Join Date: Sep 2009
Location: Beaverton, OR from WA State
Posts: 1,515
Re: 12 bolt question

It isn't a clutch-type traction device. HERE:
__________________
Devin

1983 GMC High Sierra 2500, 4x4, RC/LB, 400 S.B., SM-465, NP-208, Corporate 10 bolt & 9.5" 14 bolt
1996 GMC Sierra SLE 3500 DRW, 4x4, EC/LB, Vortec 454, NV-4500, BW-4401, AAM 925 & AAM 1050
1997 GMC Sierra SLT 1500 4x4, Z71/F44, EC/SB, Vortec 350

My Introduction with my '83s History
New Daily, the '96
83GMCK2500 is offline   Reply With Quote
Old 03-04-2013, 07:42 PM   #6
mark be
Registered User
 
Join Date: Aug 2003
Location: oregon
Posts: 54
Re: 12 bolt question

Thanks Devin
mark be is offline   Reply With Quote
Old 03-04-2013, 09:11 PM   #7
83GMCK2500
Registered User
 
Join Date: Sep 2009
Location: Beaverton, OR from WA State
Posts: 1,515
Re: 12 bolt question

No problem, I hope that helped answer your question. It is referred to as a "G80", the RPO code used to order/purchase it.
__________________
Devin

1983 GMC High Sierra 2500, 4x4, RC/LB, 400 S.B., SM-465, NP-208, Corporate 10 bolt & 9.5" 14 bolt
1996 GMC Sierra SLE 3500 DRW, 4x4, EC/LB, Vortec 454, NV-4500, BW-4401, AAM 925 & AAM 1050
1997 GMC Sierra SLT 1500 4x4, Z71/F44, EC/SB, Vortec 350

My Introduction with my '83s History
New Daily, the '96
83GMCK2500 is offline   Reply With Quote
Old 03-04-2013, 09:22 PM   #8
LONGHAIR
just can't cover up my redneck
 
Join Date: May 2004
Location: Columbus OH
Posts: 11,414
Re: 12 bolt question

That's the "replacement" for the original clutch-type "posi-traction" that GM used in the earlier years. It is known as "Gov-loc". Option code G80.
Despite the word loc in the name, it is not a locking differential. It is a clutch-type posi-traction unit that is "self-adjusting". It acts like an open differential until one wheel spins faster than the other. Then the mechanism engages the clutches, giving traction to both wheels.
They are not very strong. In a completely stock truck, driven normally, it may be ok. If you intend any heavier use, it is advisable to remove it.
__________________
You can review the site's rules here.



Quote:
Originally Posted by Longhorn Man View Post
As for reading directions...
The directions are nothing but another man's opinion.
Learn from the mistakes of others, you won't live long enough to make them all yourself...

Bad planning on your part does not necessarily constitute an instant emergency on my part....

The great thing about being a pessimist is that you are either pleasantly surprised or right.
LONGHAIR is offline   Reply With Quote
Old 03-04-2013, 09:41 PM   #9
mark be
Registered User
 
Join Date: Aug 2003
Location: oregon
Posts: 54
Re: 12 bolt question

Thanks for your help Longhair Jeramy and Devin

You've given me the info and links I need to make a decision as to put this in my '77 swb stock 350/350

Mark
mark be is offline   Reply With Quote
Old 03-04-2013, 09:47 PM   #10
88Jimmy4x4
Registered User
 
88Jimmy4x4's Avatar
 
Join Date: Oct 2003
Location: houston, texas
Posts: 1,974
Re: 12 bolt question

Quote:
Originally Posted by mark be View Post
Where are the clutches?

I found these #s on the ring gear
6270998 10:34 GM 9 782

Can't find the 3:40 ratio listed anywhere, this is all new to me so please excuse my ignorance.
10:34 >>> 34 divided by 10 = 3.40
__________________
2008 Silverado Z71 RCSB
1991 GMC Jimmy 4x4
1976 GMC Sierra C15 SWB
88Jimmy4x4 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:47 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com