76 rear diff gear calculation
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Cruising
Joined: May 2006
Posts: 11
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From: Lacombe LA
76 rear diff gear calculation
I am trying to calculate the gear ratio of my rear diff (for speedo calibration). If I spin the rear wheel 10 times and count the revolutions of the drive shaft this should give me the rear diff ratio ie 34 revs is a 3.42 37 is a 3.73. Will this work? Any ideas?
thanks
thanks
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by mjdavies
I am trying to calculate the gear ratio of my rear diff (for speedo calibration). If I spin the rear wheel 10 times and count the revolutions of the drive shaft this should give me the rear diff ratio ie 34 revs is a 3.42 37 is a 3.73. Will this work? Any ideas?
thanks
thanks
But forget about the diff. ratio of you are just trying to get the spedo working right. The teeth on the driven gear are worth about 3.x MPH each. So if you are reading 5MPH fast then you need two more teeth on the driven gear, to get close to correct.
Pro
Joined: Nov 2004
Posts: 575
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From: Nice Lake Ontario
Originally Posted by 76stingracer
I nomally just spin the tire one revolution and count the drive shaft. Three rotations= 3.08 just under 4 rotations=3.73 over four =4.11
3 & 1/4 rotations = 3.23s
3 & 1/2 rotations = 3.55s
4 & 1/2 rotations = 4.56s
Drifting
Joined: Mar 2005
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From: Burlington WI
Here is a link...
Melting Slicks
Joined: Mar 2006
Posts: 3,342
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From: Connecticut
Originally Posted by fl_rider
Thanks!
