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post #1 of 4 Old 02-05-2002, 12:45 AM Thread Starter
jeepster18_88
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Post gear ratio search

Does anyone know how I can find the gear ratio in my '85 CJ7 w 4.2 & A/C without tearing into my differentials? What was your stock gear ratios? Thanks.


Josh
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post #2 of 4 Old 02-05-2002, 09:09 AM
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Clean up the grease on the axle housing and look for the code (assuming none has swaped them):
http://www.jeeptech.com/axle/amc20.html

Also, you can jack up one rear wheel, and do that thingy where you rotate the tire once, and se how many time the driveshaft turns. If its less than 3, its likely 2.73, if its a little over 3, it 3.31, 3 1/2 times, 3.54, and so on . . .

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post #3 of 4 Old 02-13-2002, 07:13 PM Thread Starter
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I've been told by many people that I could find approximately the gear ratio by jacking up the rear end, marking the tire and driveshaft, turning the tire one full turn while counting the driveshaft revolutions. It makes perfect sense and I tried it, but I only had one side jacked up. The ratio appears to be about 1.3 to 1.
What I'm saying is for 1 full turn of the tire, the driveshaft turns about 1 and a third times. I know that there was no such ratio made for the AMC 20 but that is the results. Could me not jacking up the other side have anything to do with the screwed up results. Thanks.

Josh
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post #4 of 4 Old 02-17-2002, 03:40 PM
diamatron
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I am having the same thing haoppen here. I assumed with the 1.3 ratio only truning the one wheel doubling it woudl make 2.6. Guessing I have the dreaded 2.73 axles.

I will upgrade in the future.

"Use up what ya got, then buy what ya want"!
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