ClassicOldsmobile.com  

Go Back   ClassicOldsmobile.com > Repair & Restoration > Transmission and Driveline > Drivetrain/Differentials
Sign in using an external account
Register Forgot Password?
Search

Welcome to Classic Oldsmobile Forum!
Welcome to Classic Oldsmobile forum,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to start new topics, reply to conversations, privately message other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Classic Oldsmobile Forum today!


Reply
 
 
 
submit to reddit
 
LinkBack Thread Tools Search this Thread Display Modes
Old February 25th, 2010, 04:32 PM   #1
Registered User
 
delta881972's Avatar
 
Join Date: Jul 2008
Location: sedro-woolley, WA
Posts: 74
how do i check the rearend gear ratio

i read in a post here mention of checking the ratio by jacking the car up and turning the rear tire while counting the revolutions of the driveshaft. can anybody give me instructions on how to go about this and how to interpret my results? im assuming my 72 delta has the stock rear end (not even sure what the stock ratio is) due to the 2bbl carb on it.... seems that would be the first step in performance upgrades. a simple test like watching the driveline spin will tell me for sure.

what should the stock ratio be? its a 72 delta 350 2bbl with a th375

thanks in advance for the help
__________________
"It's got too many wheels to be fun... but it's still cool."

"My heart says 'build a mopar', my wallet says 'F*** You, you're building an Olds!' "


-1972 delta88 royale convertible 350/th375 but soon to be 455/th400.
-2005 H-D nighttrain. big bore, flattops, PC3, SE203 cams, thunderheader, hypercharger, vpc clutch w/SE spring
-1998 H-D dyna. SE heads, zero decked, cometic gaskets, hypercharger, SE ignition, thunderslide, SE23 cam, flattops, VPC cluch w/SE spring.
delta881972 is offline   Reply With Quote
Old February 25th, 2010, 06:14 PM   #2
Seasoned beater pilot.
 
J-(Chicago)'s Avatar
 
Join Date: Jan 2007
Location: Chicago
Posts: 5,396
Pull the cover and check.
The other method is only an estimate, and a waste of time in my opinion.
New fluid isn't a bad idea.

Beautiful car by the way. I used to have a 72 88 convertible.
__________________
http://classicoldsmobile.com/forums/image.php?type=sigpic&userid=3231&dateline=1261736  390
J-(Chicago) is offline   Reply With Quote
Old February 25th, 2010, 06:46 PM   #3
Lt. Buzzkill (ret.)
 
copper128's Avatar
 
Join Date: Mar 2004
Location: Western New York
Posts: 1,233
Chances are good it'll be a 2.73 or 3.08 open.
Have you checked for the stamped code on the RH axle tube?
copper128 is offline   Reply With Quote
Old February 25th, 2010, 07:38 PM   #4
Registered User
 
delta881972's Avatar
 
Join Date: Jul 2008
Location: sedro-woolley, WA
Posts: 74
thanks. i was hoping the cheaters way to check would save me some time and money lol but ya i see your point. its not a posi and no i havent checked for a code... wasnt aware there was one. can you give an example of what im looking for? ie: six digit number, letter code, 9Mxxx

thank you
__________________
"It's got too many wheels to be fun... but it's still cool."

"My heart says 'build a mopar', my wallet says 'F*** You, you're building an Olds!' "


-1972 delta88 royale convertible 350/th375 but soon to be 455/th400.
-2005 H-D nighttrain. big bore, flattops, PC3, SE203 cams, thunderheader, hypercharger, vpc clutch w/SE spring
-1998 H-D dyna. SE heads, zero decked, cometic gaskets, hypercharger, SE ignition, thunderslide, SE23 cam, flattops, VPC cluch w/SE spring.
delta881972 is offline   Reply With Quote
Old February 25th, 2010, 07:59 PM   #5
Registered User
 
Join Date: Jun 2009
Location: San Jose, CA
Posts: 2,283
It should be a 2 letter code I believe.
__________________
Randy
1970 442 (wrecked and sold)
svnt442 is offline   Reply With Quote
Old February 25th, 2010, 08:09 PM   #6
GM Enthusiast
 
OLD SKL 69's Avatar
 
Join Date: Jan 2007
Location: Long Island, New York
Posts: 3,620
darrellingold@gmail.com
Yes, you are right, it should be a 2 letter code on the right side front of the axle tube.
__________________


Darrell

1971 Cutlass Supreme, 46k original miles
1963 Buick Riviera, owned since '86, 89k org miles
1985 Buick Riviera Convertible (307 Olds)
2011 Dodge Ram QC 4x4 Hemi
OLD SKL 69 is offline   Reply With Quote
Old February 25th, 2010, 08:11 PM   #7
Just an Olds Guy
 
Allan R's Avatar
 
Join Date: Jul 2008
Location: Edmonton, Alberta. And "I am Can 'eh' jun - eh"
Posts: 16,709
Quote:
Originally Posted by delta881972 View Post
i read in a post here mention of checking the ratio by jacking the car up and turning the rear tire while counting the revolutions of the driveshaft. can anybody give me instructions on how to go about this and how to interpret my results? im assuming my 72 delta has the stock rear end (not even sure what the stock ratio is) due to the 2bbl carb on it.... seems that would be the first step in performance upgrades. a simple test like watching the driveline spin will tell me for sure.

what should the stock ratio be? its a 72 delta 350 2bbl with a th375

thanks in advance for the help
On the passenger side of the axle tube you will have stampings that identify the ratio. If you have a stock 72 Delta with a 350 it should have code NK, NA, or QJ. The first 2 are for 2:73 and 3:08. The last one is for limited slip 2:93 gears.

Here's something that might help you find the stampings
Click the image to open in full size.
__________________

The opinions expressed by Allan R are solely those of an Olds enthusiast and are not in any way meant to hinder a relationship between other Olds fans and their dreams...

Scientia est vox
Allan R is online now   Reply With Quote
Old February 26th, 2010, 05:43 AM   #8
Landyacht Club President
 
Olds64's Avatar
 
Join Date: Jul 2007
Location: Lawton, OK
Posts: 7,336
Allan you da man!
__________________
1971 Oldsmobile 98
2011 Ford Flex
Olds64 is offline   Reply With Quote
Old February 26th, 2010, 06:22 AM   #9
Moderator
 
Jamesbo's Avatar
 
Join Date: Jun 2008
Location: Atlanta, Georgia
Posts: 9,716
Joe P's "Cheater method"

Jack up the rear of the car. Make a chalk mark on one tire and on the driveshaft. Turn the tire ten times while counting the number of driveshaft revolutions. Divide the driveshaft revs by ten. That's the ratio. You can also do this by rotating the tire once, but the difference between 3.31 and 3.42 (as an example) is impossible to discern. On the other hand, the difference between 33.1 and 34.2 is easy to see. That's why I use ten turns of the tire.

Isn't cut and paste wonderful.
__________________


69 H/O burnt to a crisp 9/4/2010
69 442 convertible
69 Vista Cruiser
69 442 hardtop gone to a new home

"Growing old is mandatory,Growing up is optional"
Jamesbo is offline   Reply With Quote
Old February 26th, 2010, 09:37 AM   #10
Registered User
 
delta881972's Avatar
 
Join Date: Jul 2008
Location: sedro-woolley, WA
Posts: 74
thanks everybody! everyone here is so helpful. this is my first oldsmobile, well my first car project really, and im excited about doing a lot of it myself. i dont know what i would do without having a resource like your olds forum to glean information, ideas, and instructions from!

thanks again to everyone here that helps out those of us who would be lost otherwise
__________________
"It's got too many wheels to be fun... but it's still cool."

"My heart says 'build a mopar', my wallet says 'F*** You, you're building an Olds!' "


-1972 delta88 royale convertible 350/th375 but soon to be 455/th400.
-2005 H-D nighttrain. big bore, flattops, PC3, SE203 cams, thunderheader, hypercharger, vpc clutch w/SE spring
-1998 H-D dyna. SE heads, zero decked, cometic gaskets, hypercharger, SE ignition, thunderslide, SE23 cam, flattops, VPC cluch w/SE spring.
delta881972 is offline   Reply With Quote
Old February 26th, 2010, 09:42 AM   #11
Landyacht Club President
 
Olds64's Avatar
 
Join Date: Jul 2007
Location: Lawton, OK
Posts: 7,336
I bet you have a 4.88 spool in your car!
__________________
1971 Oldsmobile 98
2011 Ford Flex
Olds64 is offline   Reply With Quote
Old February 26th, 2010, 09:42 AM
ClassicOldsmobile
1957 Oldsmobile




Paid Advertisement
 
 
 
submit to reddit
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
1966 442 Gear Ratio 442 Guatemala 442 8 January 15th, 2010 10:43 AM
Gear ratio on 67 Cutlass ? squirell General Questions 9 July 7th, 2009 09:01 AM
Gear Ratio Recommendations Maverick Drivetrain/Differentials 9 February 23rd, 2008 02:27 AM
gear ratio question jeffs 89 cutlass salon Drivetrain/Differentials 1 August 21st, 2007 07:57 PM
1966 Transmission, positraction, gear ratio 442 Guatemala Transmission 0 June 11th, 2007 10:19 AM


All times are GMT -7. The time now is 04:44 PM.


Advertising - Privacy Statement - Terms of Service - Jobs
All content Copyright 2008 by Internet Brands, Inc.

Search Engine Friendly URLs by vBSEO 3.5.2

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62