Another differential question - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 04-27-2004, 04:00 PM
SAATR's Avatar
Member
 
Last wiki edit: Header design
Last journal entry: And still more pics...
Last photo:
Join Date: Dec 2003
Location: Shreveport, LA
Age: 29
Posts: 247
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
Another differential question

The build sheet on this 78 gmc pickup that I've been looking at has an RPO code G80 - Rear Axle Locking Type, and I was wondering if this meant it was a posi axle or something else. In case you didn't read my previous thread, it's a 78 gmc 3/4 ton, 14 bolt rear axle. Thanks.

Travis

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 04-27-2004, 05:06 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,658
Wiki Edits: 0

Thanks: 15
Thanked 60 Times in 57 Posts
a locking rear isn`t what the name says, this is where many get confused on rear types. The factory never installed a locked spool rear in any vehicle, as it wouldn`t be very safe.
what your rear has is a limited slip differential, "posi traction" is just the GM name for it, they use clutch packs or cones, so that in a straight line, both tires apply traction, but in a curve one side free wheels and the other turns. Ford used limited slip differentials and called them "traction lok" Chrysler also used them and called them "sure grip" differentials, another GM name was "Safe T Track" In most cases on GM vehicles they have a tag that says "use limited slip diffential fluid only" and this confuses people even more, they add the regular fluid that you buy at a parts store that says it works in limited slip diffs, and the rear chatters and pops like crazy, then they think the rear is no more good so they change it. These rears require GM additive which you can buy at the GM parts counter for around $11, it comes in like a 6oz bottle and cures the chatter and pop problem, but if you buy red line synthetic or royal purple synthetic diff lube, the additive isn`t needed.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 04-27-2004, 07:09 PM
M&M CUSTOM's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Transmission identification
Last journal entry: 1988 Suburban, the project continues.
Last photo:
Join Date: Mar 2003
Location: Northwest Pennsylvania.
Age: 43
Posts: 2,231
Wiki Edits: 9

Thanks: 0
Thanked 1 Time in 1 Post
Like DoubleVision said, you most likely have a clutch type differential posi/limited-slip.

I have heard that Detroit lockers came in them axles but have never seen one from the factory, or even seen anything on the internet to prove this either.

It however COULD contain the Gov-Lok centrifugally actuated factory locker, otherwise known as the "exploding locker" as it actuated by centrifugal force counteracting the spring loaded weights and engagement members.

The only positive way to identify which type you have would to be to open the case.

My '82 C-10 also has the G80 code but I couldn't tell you which type of carrier or what gears it has, as I have never removed it.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 04-27-2004, 09:15 PM
SAATR's Avatar
Member
 
Last wiki edit: Header design
Last journal entry: And still more pics...
Last photo:
Join Date: Dec 2003
Location: Shreveport, LA
Age: 29
Posts: 247
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
That good fellas, at least I can be pretty sure it's got a posi, less to buy down the road. " Exploding locker" eh? That doesn't sound good, hopefully it won't grenade on me. Thanks for the info!

Travis
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 06:17 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.