The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 02-08-2007, 05:13 PM   #1
TooT
Active Member
 
TooT's Avatar
 
Join Date: Apr 2005
Location: Jonesborough, TN
Posts: 390
Rearend ID help?

We have a 6 lug posi but dont know what the gears are....here are some numbers we got off of it. 3817776H? and a A217. can anybody help? it came out of a 68 burban.
TooT is offline   Reply With Quote
Old 02-08-2007, 05:20 PM   #2
Longhorn Man
its all about the +6 inches
 
Longhorn Man's Avatar
 
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
Re: Rearend ID help?

why not pull the cover off and count the teeth? You divide the # of drive tteth by the number of driven teeth. Anything coulda happened in the last 39 years of that suburban's life, and the one thing that DIDN'T happen nearly enough, is diff oil being chainged. It's probably 20 years overdue for one, leaving the oil only working at 50% (worst case..assuming not contaminated)
Longhorn Man is offline   Reply With Quote
Old 02-08-2007, 05:31 PM   #3
GREASEMONKEY72
Registered User
 
GREASEMONKEY72's Avatar
 
Join Date: Aug 2006
Location: Bakersfield,CA
Posts: 7,893
Re: Rearend ID help?

just pull the cover and count them and clean as much of the old oil as you can out of there im sure its black and stinkier than normal and put some new stuff in there and make it easier on the gears with the nice new oil
__________________
-steven
Alte Seele S.S.

"Allison" '72 C/10 LWB 350SB/TH350 - DD

PITBULL IS NOT A CRIME
GREASEMONKEY72 is offline   Reply With Quote
Old 02-08-2007, 06:01 PM   #4
tphsmith
still buypickupparts
 
tphsmith's Avatar
 
Join Date: Sep 2003
Location: charlotte
Posts: 637
Re: Rearend ID help?

if you drain the oil and remove the back cover rotate the rear end with the cover off you would be able to see the stamed code on the gears and check the code out on a gear chart that is avaiable on the forum here, matter of fact Im pretty sure it wasif I recall Longhorn man helping me decode mine
__________________
Its Gonna be a Great Day, I woke up this Morning.

72 SWB Fleetside freshly painted. putting a 94 LT1 with
700R4 tranny lowered 4 in the front 6 in the back

81 chevy half ton 350

89 Silverado 4x4 going ta church truck
tphsmith is offline   Reply With Quote
Old 02-08-2007, 06:08 PM   #5
1969k10stepside
Registered User
 
Join Date: Mar 2006
Location: USA
Posts: 21,020
Re: Rearend ID help?

Check for the 2 sets of numbers and see what ratio they are that way.Here is a list.

Ratio 2.56:1 - Tooth Combination 41,16
Ratio 2.73:1 - Tooth Combination 41,15
Ratio 3.07:1 - Tooth Combination 43,14
Ratio 3.08:1 - Tooth Combination 40,13
Ratio 3.08:1 - Tooth Combination 37,12
Ratio 3.31:1 - Tooth Combination 43,13
Ratio 3.36:1 - Tooth Combination 37,11
Ratio 3.42:1 - Tooth Combination 41,12
Ratio 3.55:1 - Tooth Combination 39,11
Ratio 3.73:1 - Tooth Combination 41,11
Ratio 4.10:1 - Tooth Combination 41,10
Ratio 4.11:1 - Tooth Combination 37,9

Last edited by 1969k10stepside; 02-08-2007 at 06:08 PM.
1969k10stepside is offline   Reply With Quote
Old 02-08-2007, 06:22 PM   #6
GREASEMONKEY72
Registered User
 
GREASEMONKEY72's Avatar
 
Join Date: Aug 2006
Location: Bakersfield,CA
Posts: 7,893
Re: Rearend ID help?

mine is a 3.07 and a when you find the numbers you can look at the chart or divide them, drive divided by driven example 43 divided by 14 = 3.07
__________________
-steven
Alte Seele S.S.

"Allison" '72 C/10 LWB 350SB/TH350 - DD

PITBULL IS NOT A CRIME
GREASEMONKEY72 is offline   Reply With Quote
Reply

Bookmarks


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

Forum Jump


All times are GMT -4. The time now is 10:57 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com