10 Bolt 8.5in. 3.08 HELP - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old 10-24-2014, 10:16 PM Thread Starter
 
mtman's Avatar
 
Join Date: Feb 2014
Location: Superior,Mt.
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
10 Bolt 8.5in. 3.08 HELP

Hi, My 74 came with 10 bolt 8.5in. 3.08 gears. Now sitting up on blocks I turn one wheel and the other wheel does nothing and finally starts to turn. So I thought it was trashed, so I pulled the cover off to see what I could see. Well the oil was a little dirty but not muddy and no chunks of metal. All the gears look OK, so turning the wheel and watching inside it seems to turn ok but still waiting for other wheel to catch up. the ring gears # 2 GM 3804028 13 40 11 73 the 11 is questionable. Any help with what's going on in there ? Thanks Mike
mtman is offline  
Sponsored Links
Advertisement
 
post #2 of 5 (permalink) Old 10-24-2014, 11:01 PM
Administrator
 
05GTO's Avatar
 
Join Date: Oct 2004
Location: Deliverance, GA
Posts: 5,139
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Quote:
Originally Posted by mtman View Post
Hi, My 74 came with 10 bolt 8.5in. 3.08 gears. Now sitting up on blocks I turn one wheel and the other wheel does nothing and finally starts to turn. So I thought it was trashed, so I pulled the cover off to see what I could see. Well the oil was a little dirty but not muddy and no chunks of metal. All the gears look OK, so turning the wheel and watching inside it seems to turn ok but still waiting for other wheel to catch up. the ring gears # 2 GM 3804028 13 40 11 73 the 11 is questionable. Any help with what's going on in there ? Thanks Mike
I believe it indicates;

13 = pinion gears #
40 = ring gears #

40 divided by 13 = 3.07692303

11 = November
73 = 1973

Possible a build date,

But I could be wrong!

Randy


05GTO is online now  
post #3 of 5 (permalink) Old 10-25-2014, 09:43 PM
 
Join Date: Sep 2014
Location: Taos,N.M.
Posts: 54
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
[B]what it means to me is that you have a open type rear diff. as oposed to a limited slip rear diff.3.08 gears were designed for hyway fuel economy, and not for quick accelaration, when one wheel is rotated by hand, the other wheel rotates in the oposite direction , as long as diff doesn't whine or clunk when driving all is normal. Hope that answers some of your questions.
torrid red sap is offline  
 
post #4 of 5 (permalink) Old 10-26-2014, 12:23 PM
 
chuckha62's Avatar
 
Join Date: Apr 2010
Location: NorCal
Posts: 711
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Sounds like it is working as intended for an open differential.

When the only tool in your toolbox is a hammer, you tend to see every problem as a nail.
chuckha62 is offline  
post #5 of 5 (permalink) Old 10-26-2014, 11:36 PM Thread Starter
 
mtman's Avatar
 
Join Date: Feb 2014
Location: Superior,Mt.
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks Gang, Looks like a total rebuild. Just need to decide the TH400, or pickup a700R4 Need to start a new thread about trans. rear tire size. Thanks Mike
mtman is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions.

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user 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:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
1964 12 bolt to 10 bolt remy30006 1964-1974 Tempest, Lemans & GTO Exhaust, Suspension, Alignment, Fuel Tank and Brakes. 10 08-06-2013 11:53 PM
12 bolt JLuger 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions. 5 09-09-2012 05:18 PM
Is the 10 Bolt 8.2 BOP Carrier the same as Chevy 10 Bolt? mighty454 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions. 6 04-21-2010 04:30 PM
10 Bolt Versus 12 Bolt Rear Axle take5 1964-1974 Tempest, Lemans & GTO Exhaust, Suspension, Alignment, Fuel Tank and Brakes. 10 09-28-2009 04:45 PM
69 GTO 10 bolt non-posi convert to 12 bolt posi AzStateFan 1964-1974 Tempest, Lemans & GTO Undercarriage, Frame, Transmission and Differential Discussions. 0 09-12-2009 05:34 PM

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

 
For the best viewing experience please update your browser to Google Chrome