Dana 30

[randy2117]

Im looking for the gear ratio on my Dana 30 its on a 79 Cj5 with the amc 304 does the vin# help?

 

[flatie46]

Im looking for the gear ratio on my Dana 30 its on a 79 Cj5 with the amc 304 does the vin# help?

I found mine stamped on the rear axel to the right of the cover. There's a flat spot, should be a letter or letters stamped into it. There's a chart somewhere on the net, can't remember wher I found it. Seems like I googled CJ axel ratio chart or something.

 

[69jeepcj]

It should be 3.54 unless someone changed it.

 

[jps4jeep]

easist way to be sure is to pop the diff cover off and look at the side of the ring gear. There is a series of number stamped on the side. Divide the first number (ring gear teeth) by the second number (pinion gear teeth) and you get your ratio.

for example 37/9 = 4:11

 

[69jeepcj]

You could also jack both rear wheels off the ground, put trans in the highest gear for a 1.1 drive. mark your driveshaft and have a friend help you turn both rear wheels at the same time one whole turn and count how many times your driveshaft turns. example: 3 1/2 turns would be 3.54, 3 3/4 turns 3.73, a little over 4 turns 4.10 and so fourth. Its not exact but gives you a real close guess.