I just got a used set of 3:42 rear gears and I just wanted to make sure they are actually 3:42 before I install them. They are GM gears and the only identification numbers on them are ( 12:41 GM 7 5/8 ) . Is there a quick way to confirm that they are actually 3:42? I dont have any other sets of gears to compare them to.Is there is a measurement or tooth count I can do? Any help would be great . thanks

 

Yes, divide the number of teeth on the Ring Gear by the number on the Pinion.

 

41 divided by 12 = 3.416666666666667.

Sounds like 3.42's to me.

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Thanks, I figured the 12 41 had some signifigance but I didnt realize they were the tooth count on the ring and pinion.Well it looks like they are 3:42.You learn something everyday. Thanks for the help.