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How to determine rear gear ratio

  • Thread starter Thread starter monsterstang70
  • Start date Start date Sep 21, 2004

monsterstang70

New Member
Jun 24, 2004
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Amityville, NY
Sep 21, 2004
#1
  • Sep 21, 2004
  • #1
I'm about to get a 8.8 rear and the seller isnt sure if it have 3.27's or 3.55's in it. Is there a way to determine what gears are in the rear when the rear is out of the car?
Thanks
Jhery
 

65ShelbyClone

Founding Member
Sep 9, 2000
4,675
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119
Antelope Valley, SoCal
Sep 22, 2004
#2
  • Sep 22, 2004
  • #2
Its easiest to do when its out of the car. There are two ways:

1. Spin a wheel/axle exactly one revolution and count how many turns you get out of the pinion yoke. 2 3/4 = 2.73, 3 = 3.08, etc

2. Do the revers of above. Count how many turns of the yoke it takes to make an axle go around once.

Or if the diff cover is off, count the teeth on the ring gear and divide by how many are on the pinion. This will give you the exact ratio.
 

giddyup306

Founding Member
Oct 22, 2002
3,041
2
59
Sep 22, 2004
#3
  • Sep 22, 2004
  • #3
monsterstang70 said:
Is there a way to determine what gears are in the rear when the rear is out of the car?
Thanks
Jhery
Click to expand...

pinion/ring=gear reduction
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
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129
Sep 22, 2004
#4
  • Sep 22, 2004
  • #4
Giddyup is right - to add in case of confusion, he is saying to count teeth and divide per his formula.
 
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