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 10-27-2014, 07:09 PM   #1
gripnrip
Gripnrip
 
Join Date: Nov 2008
Location: richmond utah
Posts: 63
Gear ratio ?

Checking gear ratio and count 41 on the ring and 18 on the pinion. My calculations give a .439 ratio. Any ideas?
gripnrip is offline   Reply With Quote
Old 10-27-2014, 07:31 PM   #2
NC67Chev
Senior Member
 
NC67Chev's Avatar
 
Join Date: Oct 2009
Location: Greensboro, NC
Posts: 698
Re: Gear ratio ?

wouldn't that be 2.28?
__________________
1967 Chevy C-10, 250 L6, Powerglide, 3.73, SWB, Fleetside

Upgrades: Power steering, Offset air cleaner, Rear Sport bumper, 3 point safety belts, HEI, -1/-2 springs, 16x5 wheels, McGaughy's disc brake conversion, Sway bar
NC67Chev is offline   Reply With Quote
Old 10-27-2014, 07:35 PM   #3
SS Tim
Registered User
 
SS Tim's Avatar
 
Join Date: Aug 2010
Location: Edwards, CA
Posts: 7,503
Re: Gear ratio ?

The gear ratio x.xx:1 is based on the number of driveshaft revolutions required to turn the ring gear one time. Thus the ring gear count (41) is divided by the pinion gear (18) resulting in a 2.28:1 ratio.
SS Tim is offline   Reply With Quote
Old 10-27-2014, 07:44 PM   #4
JimKshortstep4x4
Senior Member
 
Join Date: Jul 2001
Location: Muskegon,MI,USA
Posts: 6,026
Re: Gear ratio ?

I have not ever heard of a a 41 tooth ring gear with an 18 tooth pinion. If this is a truck is there any chance that you miscounted?

My calculations show the ratio is 2.27 to 1 going by the numbers you posted.

Jim
__________________
1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end
1965 Impala SS 400 sbc, Muncie rock crusher
1966 Impala SS 396 bbc, TH 400
1969 El Camino, 350 sbc, TH 350
1971 Snowplow built on a Blazer frame
1972 GMC Short bed, stepside, TH 400, 427 BBC
JimKshortstep4x4 is offline   Reply With Quote
Old 10-27-2014, 09:03 PM   #5
Exgie
Registered User
 
Join Date: Oct 2014
Location: Denver Colorado
Posts: 9
Re: Gear ratio ?

Quote:
Originally Posted by jimkshortstep4x4 View Post
i have not ever heard of a a 41 tooth ring gear with an 18 tooth pinion. If this is a truck is there any chance that you miscounted?

My calculations show the ratio is 2.27 to 1 going by the numbers you posted.

Jim
2.27777~7778 = 2.28
Exgie is offline   Reply With Quote
Old 10-27-2014, 09:39 PM   #6
Bigdav160
Registered User
 
Bigdav160's Avatar
 
Join Date: Apr 2011
Location: Klein Texas
Posts: 3,852
Re: Gear ratio ?

The lowest I've heard of is a 2.41:1 The rear end in my Camaro came out of a '78 Trans Am and it was originally a 2.56:1 (41:16)
__________________
My Classics:
'72 K20 Suburban + '65 Dodge Town Wagon
'72 Corvette Roadster +'67 Corvette Roadster
'73 Z-28 Camaro
'63 Ford SWB Uni Pickup
'50 Ford Coupe
Bigdav160 is offline   Reply With Quote
Old 10-27-2014, 10:14 PM   #7
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,516
Re: Gear ratio ?

What type of rear and year, look for numbers on the ring gear
kwmech is offline   Reply With Quote
Old 10-27-2014, 10:36 PM   #8
Fitz
Account Suspended
 
Join Date: Jan 2007
Location: Tucson
Posts: 2,183
Re: Gear ratio ?

Quote:
Originally Posted by gripnrip View Post
Checking gear ratio and count 41 on the ring and 18 on the pinion. My calculations give a .439 ratio. Any ideas?
You should count those teeth on pinion and ring gear again.
Fitz is offline   Reply With Quote
Old 10-27-2014, 10:45 PM   #9
LockDoc
The Older Generation


 
LockDoc's Avatar
 
Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 25,465
Re: Gear ratio ?

-
Rear Axle Ratios

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

LockDoc
__________________
Leon

Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles

(My Dually Pickup Project Thread)

http://67-72chevytrucks.com/vboard/s...d.php?t=829820

-
LockDoc is offline   Reply With Quote
Old 11-03-2014, 04:02 AM   #10
gripnrip
Gripnrip
 
Join Date: Nov 2008
Location: richmond utah
Posts: 63
Re: Gear ratio ?

Well I just nominated myself for the "Barney of the month" award. I did count wrong. Turns out I was counting a shaft gear or something instead of the carrier gear. The rear end is in fact a 4.10, 8 lug, 14 bolt. Now I know. Thanks for all the ideas.
gripnrip 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 02:33 AM.


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