Ring and Pinion Swap in a 2nd Gen Firebird - 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 02-04-2006, 03:10 PM
Blank's Avatar
Registered User
 
Join Date: Feb 2006
Location: Georgia
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ring and Pinion Swap in a 2nd Gen Firebird

Hello guys,

I'm building a 1981 Trans Am and am having an issue with the rear end.

The powertrain of the car is pretty custom, Chevy 350 with an M-21, and a Rear end out of a 1976 Firebird. I was told the rear end was a 2.41 Posi, and seem to remember running the numbers to confirm it...

Anyway, given the very high first gear in an M-21 and the rear end, it is making the car near impossible to drive, so I was looking into changing the ring and pinion to be a 3.73 like was designed for the transmission.

I've been looking and found there are two different carriers for this particular 10 bolt rear end, and the ones I've found are for the larger of the two carriers. I've also been told that I can purchase a ring spacer for my rear end to put these gears into my rear. So, my question is, can such a simple fix allow me to change out the gears? And if so, will that spacer weaken my rear end significantly?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-04-2006, 06:58 PM
Registered User
 
Join Date: Jan 2005
Location: Brookfield, WI
Age: 53
Posts: 499
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Buy the correct posi carrier for the differential. Ring gear spacers do not allow the ring gear to be centered and positioned on the carrier. The inner bore of the ring gear is meant to be firmly seated on the machined OD of the carrier; ring gear spacers destroy this location. I'm sure there are many who have done the ring gear spacer, however, it is not a recommended device. Using them places all the torsional load on the ring gear bolts which will lead to broken bolts.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-04-2006, 07:03 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: 42
Posts: 2,230
Wiki Edits: 9

Thanks: 0
Thanked 1 Time in 1 Post
Chazmac is absolutely correct.

Find a gear set that will bolt up to the 2-series carrier you have, or replace the carrier with a 3-series.

Of course if you replace the carrier, you can get any limited slip or posi you choose that will fit your axle housing.

Your 1976 housing should contain an 8.5 inch ring gear.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-10-2006, 09:18 AM
Blank's Avatar
Registered User
 
Join Date: Feb 2006
Location: Georgia
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Just to clarify, it would just be the carrier that I would have to replace and not the whole axle? Would I have to replace the axles themselves as well?

Does anyone have a location to get a ring gear for a series 2?

What are the differences between the series 2 and series 3 axles?

Finally, if I'm using this axle for the street, what sort of life expectancy should I expect from a spacer'ed axle?

Sorry for all the questions, I'm trying to get a very quick education on these rear ends, and thanks for the help guys.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-10-2006, 10:57 AM
Registered User
 
Last photo:
Join Date: Nov 2004
Location: Cali
Posts: 994
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Changing carriers doesn't necessarily mean changing axles. The carrier break for the 8.5" GM rears is 2.56/2.73, and you'll want the carrier for the 2.73 and up gears, along with the gearset and installation kit.
Call West Coast Differentials in Sacramento and they'll have all the numbers you need. 800-510-0950
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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ring and pinion swap NovaSS350 Transmission - Rearend 13 10-06-2004 10:05 AM
pinion/ ring gear exchange chevyman06 Transmission - Rearend 2 06-24-2004 05:47 AM
Which Ring & Pinion Kit? Ford 8.8" nightrain_rod Transmission - Rearend 0 12-03-2003 10:48 PM
ring and pinion help Pontiacman Transmission - Rearend 0 11-13-2003 05:09 PM
1965 Mustang 7 3/4" ring and pinion. dale634 Transmission - Rearend 6 12-15-2002 12:55 PM


All times are GMT -6. The time now is 01:40 AM.


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.