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Unread 08-04-2010, 07:05 PM   #1
HighFive
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Picking up axles...what to look for and how to tell ratio

I'm going to be picking up a set of widetrack d30/amc20 axles with 3.73 gears. What do you guy's suggest I look for before buying them. Also the rears don't have any wheels on them so what would be the easiest way to make sure the gears are really 3.73.

thx, rich

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Unread 08-04-2010, 07:16 PM   #2
crzdmnky
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*Check to see if they have tags...
*Remove the covers and see what numbers are on the ring gear / Count the ring and pinion gears
*Count pinion revolutions to drum revolutions

Sure someone else can chime in.
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Unread 08-04-2010, 07:31 PM   #3
Eaglekeeper
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Besides the overall condition, check where the u-bolts mount and make sure there's no gouges and the spring perches are in good shape. Not a huge issue, but more work. Watch out for any bulges or dents in the tubes; may cause tubes to be out of alignment.

To verify gears, you could spin the axle and count the pinion turns, but that will only be a estimate. Hard to tell the difference between 3.54 or 3.73. Only real way to be 100% sure is to pull the covers and check the ring gear. Should find a number stamped such as 41 11, which is a 3.73. If for some reason there is no number, count number of teeth on both the ring and pinion, the cross reference the FSM. Don't trust the codes stamped into the axle on the 20 or the tag on the 30 as the gears may have been swapped in the past. Maybe you'll get lucky and find a locker or two when you pop the covers.
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[URL="http://s1038.photobucket.com/albums/a462/E9Eaglekeeper/"]http://s1038.photobucket.com/albums/a462/E9Eaglekeeper/[/URL]
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Unread 08-04-2010, 07:44 PM   #4
yahwhy
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and maybe you'll get real lucky and have no briggs n stratton nut on the end of the axle.
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Unread 08-04-2010, 09:40 PM   #5
HighFive
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Quote:
Originally Posted by Eaglekeeper View Post
To verify gears, you could spin the axle and count the pinion turns, but that will only be a estimate. Hard to tell the difference between 3.54 or 3.73. .
How would you do this? BTW thanks for the help.
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Last edited by HighFive; 08-04-2010 at 09:50 PM..
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Unread 08-05-2010, 05:26 AM   #6
Eaglekeeper
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Quote:
Originally Posted by HighFive View Post
How would you do this? BTW thanks for the help.
Using this method assumed the axles and bearings are in decent shape and not froze up. Consider this a guesstimate method only but it will get you close. Always best to open them up and verify. It would really suck to buy two axles and find out one is a 3.73 and the other a 3.54.

I bought some axles off craigslist that sat in a field for years. Best I could tell were 3.73's in the 2 dana 30s, a 2.73 in one 20 and I thought the other 20 had 3.73's. Turned out it had 3.54's. Even if I had known the 20 had 3.54's, I still would have bought them because I needed various parts from both 20's, Backing plates were good on the 2.73 and the 3.54 carrier to replace my original 2.73 carrier so I can change Ring gear to 3.73. New 3.73 R&P and Superior Axles came in yesterday, but still waiting on the installation kit.

This link will help. Good luck.

Posted from Jedi.com; What's My Gear Ratio?

So, assuming you've got an axle up in the air with the driveshaft disconnected & neither wheel on the ground:

* If you turn one tire & the other one either stays still while the pinion rotates, or the other one rotates backward while the pinion stays still, or something in between, then you've got an open diff or a very weak LSD (like a Trac-Lok with too many miles on it). In this case, you need to secure one wheel (perhaps by lowering the tire onto the ground), then you can figure your gear ratio by rotating the airborne tire TWO full rotations and counting the number of times the pinion rotates. 3.73 turns means 3.73 gears. If you only rotate the tire once, then 1.865 turns means 3.73 gears.
* If you turn one tire & the other one turns the same number of turns in the same direction, then you've got a good LSD or locker. In this case, you can just rotate the tires ONE full rotation and figure your gear ratio by counting the number of times your pinion rotates. 3.73 turns means 3.73 gears.
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[url]http://www.jeepforum.com/forum/f8/let-games-begin-new-build-86-cj7-1046943/[/url]

A ton more pics here.
[URL="http://s1038.photobucket.com/albums/a462/E9Eaglekeeper/"]http://s1038.photobucket.com/albums/a462/E9Eaglekeeper/[/URL]
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