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Discussion Starter #1
So to start off, I am new to Jeep building. I have had my JKU for a little over a year and have made small mods to it(Light Bar, Bumper). Now I have bought the 4in Mopar lift kit with Fox reservoir shocks. I am planning on installing this with a set of 35in tires on 17in rims and was wondering if a stock Dana 44(rear)/ Dana 30(front) with a 3.21 gear ratio is strong enough. Ive hear and read mixed feelings. Should I upgrade to 3.73 gears or higher such as 4.10 and 4.56. Looking at charts it seams that a 4.10 and 4.56 are great for moderate trail use which is all the jeep will be doing.
 

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I️ personally would re-gear. Is it livable? Yes. Would I️ want to drive it all the time like that? No. If you are only going to 35’s and no larger I️ would do 4:56


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I have a 3" lift and 35's and I immediately regeared to 4.56 ....3.21 was just too sluggish...I also replaced the D30 with a D44 for wheeling purposes. If you are going to keep the 30 I would recommend beefing it up with support kits.

Saw that you looked at that chart. at 72 MPH I'm doing 2600 rpms which gives me some power to hit it to 3000 rpms to pass and go faster...rarely do I have to downshift. GL (not sure if you have auto or standard)
 

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4.56's worked for me. rear 44 is fine, maybe eventually add new axle shafts. I still have my d30 up front but it is really beefed up(as much as you can with a d30). I did keep the stock axle shafts so they break 1st...hopefully.

With a 4" lift you might start looking at driveshafts, at least a front one to start)
 

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in my experience it starts with 35's and you end up with 40's next time you need tires lol. With that said i would re-gear to a ratio that covers the span of any future mods that may come up.

As for 35's and 3.21 gears it will be sluggish and the engine will bog down going up hills or sand. This is worse in an automatic even if you reset the shift points it still has a tendency to lag. So i would re-gear to at least 4.56. You will need a new carrier for both axels and drive shaft and if you have some extra money might as well through in a locker.



Just for reference i have a 2door manual, 5.13s gears and 35s with 3.5 inch lift in front and 2.5 inch lift in the back. I like it a bit over geared. It feels more nimble and responsive and the torque to the wheels when in 4lo is amazing. But my top speed is about 60ish MPH around 2700RPMs
 

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Discussion Starter #7
Also my jeep is a standard.

So the lift is in, going this week to get it all aligned since I installed the lift myself, and then I will really see how the 35's roll.

As for axles, although lockers would be ideal, however the funds are not all there and it would'nt really do its justice. I won't be doing to extreme wheeling, mainly just light trail riding with minimal rock crawling. That being said is it still worth jumping that high of a gear? As for tires, the biggest I could see me going would be 37's. (I live in NH where they are sticklers for tires sticking out beyond the fenders)

I also ask this. Can you re gear just one axle? or will there be problems?

Thank you
 

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@LashersLair 37's and 4" lift will look better than 35's. Your going to want a regear regardless, since 3.21 is ONLY optimal for the 29" tires for best gas mileage.

Your going to want to brace the front axle's ends (axle c's) with gussets (under $100, but about $200 for labor). Its been a long time since i checked out the mopar 4" but you might need more parts to address steering. Upgrade your brakes, and especially tire carrier upgrade.
 

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Discussion Starter #10
Mopar lift kit included:
Brake Line Extensions, Coil Springs, Extended Brake Lines, Front Drive Shaft, Front Lower Control Arms, Front Track Bar, Hardware, Rear Lower Control Arms, Sway Bar Endlinks

Im going to get a terraflex tire carrier and a bumper that can accommodate a factory hitch.
 

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4.56's worked for me. rear 44 is fine, maybe eventually add new axle shafts. I still have my d30 up front but it is really beefed up(as much as you can with a d30). I did keep the stock axle shafts so they break 1st...hopefully.
I started by beefing up the D30 also, along with 4.56 and Eaton e-lockers. Then went to 36" (actual size) trail tires and worried the D30 might be problematic so I pulled it, sold it on classifieds here, and got a G2 D44. Also added new G2 Placer Gold half-shafts in back. I run 35s on the street.
 

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I started by beefing up the D30 also, along with 4.56 and Eaton e-lockers. Then went to 36" (actual size) trail tires and worried the D30 might be problematic so I pulled it, sold it on classifieds here, and got a G2 D44. Also added new G2 Placer Gold half-shafts in back. I run 35s on the street.
So, what are your thoughts on the Eaton E lockers? That's what I'm leaning towards. Still looking for lowest prices etc. They seem to be a good choice. Thanks!
 

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Mine are eatons. They have been great so far. I do not use the front locker much though. Really haven't had a need to yet. A few spots here and there. They engage pretty quickly and have had no problems at all. They work great in the rear.
 
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