3.07 or 3.08

i have an 87 with a 5spd and i have the original build sheet that came with the car that lists the features extras whatever you call them. It says it has 3.08 gears and i always see people write 3.07 and all the faq charts say 3.07. I know it doesnt really make a difference at all im just curious....which is it? does anyone know the tooth count on the ring and pinion? is it really like 3.07836 and they rounded up? whats the deal?

Yeah, they round off.

The size and tooth count of the front Dana 30 and the rear Dana 35 (or Dana 44, or Chrysler 8.25) aren't the same, so the ratios are never exactly the same, and sometimes when rounded to two decimal places they still aren't the same. For example, the automatics may work out to 3.54 or 3.55. Functionally, the difference is so slight that it's insignificant, and doesn't affect 4WD operation.

Eagle said:

Yeah, they round off.

The size and tooth count of the front Dana 30 and the rear Dana 35 (or Dana 44, or Chrysler 8.25) aren't the same, so the ratios are never exactly the same, and sometimes when rounded to two decimal places they still aren't the same. For example, the automatics may work out to 3.54 or 3.55. Functionally, the difference is so slight that it's insignificant, and doesn't affect 4WD operation.

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cool thats what i thought. Since you brought up the 4wd thing, what is the percent difference gears can be to operate safely in 4wd?

87CherokeeChief said:

cool thats what i thought. Since you brought up the 4wd thing, what is the percent difference gears can be to operate safely in 4wd?

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0.01% - same as in your 3.07 vs. 3.08 scenario. Any more than that and your chances of binding the driveline start getting better and better.