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Unread 02-26-2007, 03:21 PM   #1
Matthew Davis
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3.21 v. 4.10

Hello,

Can somebody please explain to me the nuances between 3.21 and 4.10? What exactly does it mean? What are the advantages of one over the other? It seems gas mileage is significantly effected, what else?

Thanks,

Matt

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Unread 02-26-2007, 03:26 PM   #2
igofshn
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If you plan on doing any modifications to your Jeep, then you will definately want 4.10's.
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Unread 02-26-2007, 03:42 PM   #3
woolf
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It is the final drive ratio. When your drive shaft makes a revolution, the rear end either makes 3.21 or 4.10. It is all a matter of matching your powerband, tire size, and final drive ratio. Go with the 4.10s, I personally see very little to no benefit with the 3.21s, the motor doesn't make enough power down there.
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Unread 02-26-2007, 04:07 PM   #4
Kyoseki
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Quote:
Originally Posted by woolf
It is the final drive ratio. When your drive shaft makes a revolution, the rear end either makes 3.21 or 4.10. It is all a matter of matching your powerband, tire size, and final drive ratio. Go with the 4.10s, I personally see very little to no benefit with the 3.21s, the motor doesn't make enough power down there.
Other way around, for ever 3.21/4.10 revolutions of the drive shaft, the rear wheels make 1 revolution.

Higher numbers mean more torque, which means better acceleration, but typically worse gas mileage as the engine is more efficient at lower rpms.
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Unread 02-26-2007, 04:37 PM   #5
SecondTJ
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you'll want 4.10s, mileage aside
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Unread 02-26-2007, 05:39 PM   #6
scottyc
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Quote:
Originally Posted by igofshn
If you plan on doing any modifications to your Jeep, then you will definately want 4.10's.
I plan on adding some aftermarket seat covers. Thanks for the heads up!
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Unread 02-27-2007, 05:04 PM   #7
2K1TJ
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Originally Posted by scottyc
I plan on adding some aftermarket seat covers. Thanks for the heads up!

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Unread 02-28-2007, 10:51 AM   #8
redrom01
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Quote:
Originally Posted by scottyc
I plan on adding some aftermarket seat covers. Thanks for the heads up!

Once you add those seat covers you'll be extremly happy that you got the 4.10 gears.
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Unread 02-28-2007, 10:54 AM   #9
jeepers3
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Quote:
Originally Posted by scottyc
I plan on adding some aftermarket seat covers. Thanks for the heads up!
Just make sure you do not have side impact airbags (:
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Unread 02-28-2007, 03:13 PM   #10
Matthew Davis
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Quote:
Originally Posted by scottyc
I plan on adding some aftermarket seat covers. Thanks for the heads up!
Dude, thats awsome.

Thanks for all the input everyone. This may sound odd but I never actually looked at my build sheet to see what I had. I assumed it was 3.21. It turns out that I have 4.10 due to the tow package addition. Yeah! I did not order my X, it just happen to show up on the dealer lot and had my requirements.

Thanks,
Matt
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