1.37:1 rear gear ratio???

Old April 21st, 2019, 09:05 PM
  #1  
Registered User
Thread Starter
 
Join Date: Nov 2018
Location: Independence OR
Posts: 34
1.37:1 rear gear ratio???

I have to be doing my math wrong. I rotated the driveshaft while I had my wife count the tire rotations. At 4 driveshaft rotations, my wife tells me that the tire rotated almost three times exactly. Knowing this did not sound right, I turned the driveshaft 8 times and the wheel went just over 5 and 3/4 around. I have yet to get this project car on the road for the first time since I purchased this car.
Natedawg is offline  
Old April 21st, 2019, 09:12 PM
  #2  
Registered User
 
Join Date: Nov 2011
Location: Ste Rose Manitoba Canada
Posts: 401
Not a 1.73 but maybe 2.73
Kyle's77cutlass is offline  
Old April 21st, 2019, 11:05 PM
  #3  
Registered User
 
Join Date: Dec 2010
Location: Las Vegas, NV
Posts: 1,078
only works with a "posi" & transmission in nuetral

1 rotation of the tire & count the driveshaft's revolutions
hurst68olds is offline  
Old April 22nd, 2019, 01:43 AM
  #4  
Registered User
 
Join Date: Jun 2009
Location: San Jose, CA
Posts: 3,928
If you are spinning only one tire you will only get half of the revolutions of the driveshaft due to the spider gears in the differential. That would net you a 2.73 gear ratio.
svnt442 is offline  
Old April 22nd, 2019, 05:41 AM
  #5  
1968 442 Convertible
 
bry593's Avatar
 
Join Date: Feb 2019
Location: Oklahoma
Posts: 213
And it since it is half, it also means you have an open differential, no LSD.
bry593 is offline  
Old April 22nd, 2019, 01:24 PM
  #6  
Registered User
 
Fun71's Avatar
 
Join Date: Feb 2013
Location: Phoenix, AZ
Posts: 6,418
Or a limited slip with severely worn clutches.
Fun71 is offline  
Old April 23rd, 2019, 08:19 AM
  #7  
Registered User
 
Lonnies Performance's Avatar
 
Join Date: Jan 2019
Location: Pittsburgh, PA
Posts: 88
On a non-posi car, rotate the tire 2 turns while holding the other one from turning, & count the driveshaft revolutions to get the correct ratio.
Lonnies Performance is offline  
Old April 26th, 2019, 09:14 PM
  #8  
Registered User
Thread Starter
 
Join Date: Nov 2018
Location: Independence OR
Posts: 34
You guys are awesome. You're right of course, I'm half off. That puts me at 2.73 gears thanks!
Natedawg is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
yellowrocket
Drivetrain/Differentials
8
March 8th, 2017 09:23 AM
Cutlass Fan
Drivetrain/Differentials
12
June 8th, 2016 01:30 AM
nj_cutlass72
Parts For Sale
3
April 13th, 2016 05:40 PM
1966Oldsmobile
Drivetrain/Differentials
2
September 3rd, 2013 04:55 AM
rcdynamic88
Drivetrain/Differentials
10
July 9th, 2010 07:00 AM


Thread Tools
Search this Thread
Quick Reply: 1.37:1 rear gear ratio???


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.