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AMC 20 gear ratio, how can you tell what it is?

3593 Views 2 Replies 1 Participant Last post by  Smokngun
How can you identify the gear ratio of an AMC 20 by the casting marks? The axle The AMC 20 I'm looking at has the following markings on the top N, then below that the number 891 and below that 117. If it can't be identified from those markings where are the markings used to identify it? Thanks, John

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Can you just spin the tires and count the revolutions of the input spline? That would give you a gear ratio.

There is a letter code stamped on the right rear of the diff housing that will tell you the original gear ratio and if it was equiped with a factory limited slip diff. Go to That will tell you how to decipher the code (a single or double letter).

Mike H.
1983 CJ-7 Laredo
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