Default Identifying gear ration 

Old 03-10-2019, 02:00 PM   #1
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Did some searching on the site and the web and I知 scratching my head. On my Dana 30, one full revolution on my wheel, I知 getting one and a quarter turns out of my pinion gear. That seems like an ultra high gear ratio. What am I missing?


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Default Re: Identifying gear ration 

Old 03-10-2019, 04:59 PM   #2
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There might be a tag on one of the bolts on cover with the ratio. If not check the rear diff for a code stamped on the right axle housing near the cover. Both ratios should be the same.

On edit the codes can be found on jeeptech.com look under amc 20 axle tab.

Last edited by RiverandSand; 03-10-2019 at 05:10 PM..

 

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Default Re: Identifying gear ration 

Old 03-10-2019, 06:26 PM   #3
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IF it's still the OEM ratio-Most likly 2:73 or 3:31.
Pull the diff cover-The ring gear will have it stamped on it.
You sure your rear axle is not a '44'? Many '86s were.
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Default Re: Identifying gear ration 

Old 03-10-2019, 06:49 PM   #4
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Quote:
Originally Posted by Lumpy Grits View Post
IF it's still the OEM ratio-Most likly 2:73 or 3:31.
Pull the diff cover-The ring gear will have it stamped on it.
You sure your rear axle is not a '44'? Many '86s were.
LG
He was talking about the front.

 

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Default Re: Identifying gear ration 

Old 03-10-2019, 07:19 PM   #5
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Lumpy, I wish I had a 44, but unfortunately I have a 20.

But was talking about the front. I did find these markings on it this evening.


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Default Re: Identifying gear ration 

Old 03-10-2019, 09:03 PM   #6
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Quote:
Originally Posted by Masscj7 View Post
Lumpy, I wish I had a 44, but unfortunately I have a 20.

But was talking about the front. I did find these markings on it this evening.


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Your Jeep has 2.73 gears

 

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Default Re: Identifying gear ration 

Old 03-10-2019, 11:24 PM   #7
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Yep, 49/18= 2.72s

When doing the tire to driveshaft rotation on an open diff, you need to make sure both tires are turning at the same speed. Best way is to roll the tires across the ground. If only 1 tire (or axle shaft) turns, you need to do 2 complete tire rotations. I learned that the hard way after a buddy passed up what turned out to be 3.54 WT axles because we couldn't figure out the ratio


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Default Re: Identifying gear ration 

Old 03-11-2019, 01:28 PM   #8
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2:73 ratio.

Copy on the '20'-I have seen many who 'thought' they had a '20', when in fact it was a '44'..........

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