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Unread 08-30-2011, 04:37 PM   #1
Tpeal9
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Gear ratio.

I was replacing my universal joints today and decided to try and figure out the gear ratio. I lifted up the rear end and marked the tire and the drive shaft on the side about the 3 oclock position on the shaft and the 1 o clock position on the tire. I have 33x12.50 R15 tires. I was expecting 3.55 gears. But instead of rotating 3 1/2 times the drive shaft only rotated 1 1/2. Did I do this wrong? Or can someone shine some light on the subject for me thanks.

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Unread 08-30-2011, 05:49 PM   #2
clarkjdg
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This you can figure it at http://www.grimmjeeper.com/gears.html
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Unread 08-30-2011, 05:55 PM   #3
zeus87gn
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Just lift up one tire and then do it again.
The whole rear diff in the air threw off your numbers.
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Unread 08-30-2011, 09:43 PM   #4
Tpeal9
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Quote:
Originally Posted by zeus87gn
Just lift up one tire and then do it again.
The whole rear diff in the air threw off your numbers.
Okay I'll try this out and see. Thanks!
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Unread 08-31-2011, 06:34 PM   #5
zeus87gn
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any luck?
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Unread 09-01-2011, 09:58 AM   #6
Tpeal9
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Not yet I'm pretty busy at work I'll end up doing it Friday afternoon. I'll let you know
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Unread 09-01-2011, 03:50 PM   #7
monkey710
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I am assuming there is no tag on the rear axle case? Believe it or not, but the 89 YJ I picked up still had the original tag in it. As long as no one went in to adjust the ratio, I would expect it to still be there.
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Unread 09-01-2011, 03:56 PM   #8
wahabooo
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Quote:
Originally Posted by monkey710
I am assuming there is no tag on the rear axle case? Believe it or not, but the 89 YJ I picked up still had the original tag in it. As long as no one went in to adjust the ratio, I would expect it to still be there.
Yes
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Unread 09-03-2011, 08:16 PM   #9
Tpeal9
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I didn't see a tag. But the ratio is the same with both tires off the ground and only one off the ground. 1 tire rotation= 1 1/2 drive shaft turn. It can't be right for the gear ratio to be that high. Does it matter if it's in 1st gear? Ive had it in neutral while doing it.
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Unread 09-03-2011, 08:42 PM   #10
Mark05059
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try again... mark one of the ujoint yoke bolts first.. then mark your tire at the 12 oclock position. Then rotate the tire while watching the yoke.
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Unread 09-03-2011, 09:00 PM   #11
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Pull the carrier out, count the teeth on the ring gear and divide that by the teeth on the pinion gear. It's a D35 you'll be tearing it apart soon enough. Just get some practice now while you can .
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Unread 09-06-2011, 08:44 AM   #12
Tpeal9
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Yeah I'm going to buy Dana 44's with 4.56 gears and an ARB locker whenever I save up the $3000
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