Ring Gear numbers - 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
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 08-30-2003, 11:49 PM
Registered User
Join Date: Aug 2003
Location: Winnipeg,Manitoba
Age: 40
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Red face Ring Gear numbers

I have what i think is a rear end from an 1980 z28. The #'s on the ring gear are:
GM 3984828 3 40 3 80 . Can some one help me find a web site or more info on my ear end.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 08-31-2003, 11:23 PM
jdcoic's Avatar
The Chicken Car
Join Date: Aug 2003
Location: Waldorf, MD
Age: 41
Posts: 42
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
These two websites have some pretty good info on identifying GM rearends.



There should be a set of four #s, something like 15 41 stamped on the ring gear. This will tell you what ratio it is. Just divide the big number by the little one, and that is your ratio. The example above is 2.73

There is also the turn the driveshaft method. Count the number of times you have to turn the driveshaft to make the tire make one revolution, or ten times and divide by 10 (more accurate).
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-03-2003, 07:17 AM
farna's Avatar
Last wiki edit: AMC V-8s Last photo:
Join Date: Sep 2002
Location: Batesburg-Leesville, SC
Age: 53
Posts: 1,679
Wiki Edits: 14

Thanks: 0
Thanked 22 Times in 20 Posts
If you can see the gears, simply count the teeth to find the ratio. Divide the number of teeth on the ring by the number on the pinion and you have the ratio. The extra numbers on hte ring are the specs used to install the gears originally. Everything will have to be measured again to reinstall them if they've been out or switched to another housing.
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


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 06:47 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.