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Unread 01-08-2010, 03:21 AM   #1
Chuckles0227
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question about axle gearing

i have 31's and stock 3.08's in my d30 and amc 20. I was wondering if i need to re-gear at all. I really do not know much about gearing, and i know that there are plenty of experts in the subject on this forum. I also know for a fact that i'm missing one tooth, and a few are shaved on my d30 ring gear.

as always, thanks for the help

Brent

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Unread 01-08-2010, 03:25 AM   #2
VanBCguy
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I ran a D30 front and D35 rear with stock 3.07 gearing for many wheeling trips. Take care of it, be light on the skinny peddle and you should be fine. You could regear better of course, but what you have is adequate and highly useful. It depends greatly on your driving habits and wheeling habits. I would look after whatever you know needs fixing/replacing though.
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Unread 01-08-2010, 07:16 AM   #3
78treehugger
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Regearing is a preference. Whatever you do fix the dana 30 gears. That will not last. Gearing also depends on what driveline you have and what your intended purpose is with you jeep. Hardcore offroading will require lower gears. More of a streetable jeep you shuold be fine.
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Unread 01-08-2010, 09:14 AM   #4
80cj
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Quote:
Originally Posted by Chuckles0227 View Post
i have 31's and stock 3.08's in my d30 and amc 20. I was wondering if i need to re-gear at all. I really do not know much about gearing, and i know that there are plenty of experts in the subject on this forum. I also know for a fact that i'm missing one tooth, and a few are shaved on my d30 ring gear.

as always, thanks for the help

Brent
You should fix the D30. While you're at it, you might consider a gear ratio change if you're looking for better performance. My 80 CJ-5 came with the optional (for 1980) 3.54 gears and that ratio seemed to go well with 31 inch tires and it still got decent gas mileage. 3.54 is the highest numerical ratio you can go to without changing your D30 carrier.
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Unread 01-08-2010, 11:13 AM   #5
jumbojeepman
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3.08 seem kinda low (numerically) for 31" tires. I would think you want at least 3.54's (stock on my 76 CJ-7.)
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Unread 01-08-2010, 11:58 AM   #6
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imo, you can get by just fine with your current ratio with 31" tires. but i'd be fixing the broken stuff for sure.
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Unread 01-08-2010, 01:17 PM   #7
SlikRic
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My 80 has the 3.08 gears and 31"BFG MT. i can run 85MPH down the highway and get me down any trail or through any mud i have treid. No rockcrawling here. What do you want to do with the Jeep is the queastion?
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Unread 01-08-2010, 02:19 PM   #8
PavementPounder
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Quote:
Originally Posted by DT5150 View Post
imo, you can get by just fine with your current ratio with 31" tires. but i'd be fixing the broken stuff for sure.
This is basically how I feel about it, as well. However, (to the OP) you'r going to need to spend the money on a gear setup regardless if whether you fix your problem or select another ratio. This is the time to ask yourself whether you see your vehicle's tire size growing in the future. If you think you will jump to 33's (and still run a 4-speed), you may want to consider a ratio change to something in the 3.73 area.
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Unread 01-09-2010, 02:46 AM   #9
Chuckles0227
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thanks for all the input guys. If i were to change the ratio to 3.54 would it benefit me much as a dd, with casual wheeling? also the front dif seems to be fine even with the missing tooth, i didn't actually see a broken tooth it's just that when i took the cover off and cleaned out the muck i found about a 1 inch piece of metal that looked like a tooth to me, with some metal shaving. As of right now im really going for as much gas mileage as i can get. im currently getting 12-13mpg running 89 and 10 with 87, i also know that im running a bit rich, but that's a completely different issue

cheers,
Brent
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