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Discussion Starter #1
Could use some first hand perspective on the two mods referenced above.

My jeep was a stock 2007 2-door JK when new but now is a very capable vehicle for intermediate and advanced intermediate runs. But the two mods that everyone keeps mentioning are on my mind.

When you regear your vehicle, what are the advantages, in a nutshell? Does it affect only the low gears or the high gears as well? If it's such an advantageous upgrade, why doesn't jeep build the new vehicles that way?

Also, how effective, in truth, are the sleeve/gusset jobs? Does anyone have real life experience? If I upgrade to a 4-inch lift and 35" tires, it is essential?

Thanks for any advice!
 

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Regearing changes the the gearing in your differential. So all speeds will be effected. Think of a 10 speed bike. Your transmission is the sprocket at the peddles. The differential is the sprocket at the back tire. Jeep choose the gears they do for fuel economy on stock tires. Changing your tire size will require a differential regear to gain those ratios back.
 

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You do not need or even want a 4 inch lift for 35 inch tires, especially on a two door. A 2.5 lift will be enough.

Especially with the 3.8 engine, regearing is one of the best things you can do to your Jeep.

I did a full truss/gusset rather than sleeve since I rock crawl.
 

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To start off... 4" of lift with 35s is way to much. 2.5" - 3" will fit nicely with plenty of clearance. Any reputable manufacturers lift kit is going to gain you more than advertised. Sometimes by a significant amount depending on how the Jeep is outfitted. Plus once you hit 3.5" of lift then there is a whole boat of other mods that should be made to the suspension and steering to fix some driveability issues you will start to encounter.
So gearing is one of those mods that most people hate to do because of the expense of it but, once done kick themselves for not doing it sooner. It really is a game changer. The gearing change is in the front and rear differentials so it effects both high and low range. At minimum it gets you back the torque that you lost when you installed bigger tires but most people gear it down even further for an off road vehicle. My JK has the 3.8 and with the stock 3.21 gearing was at best a DOG. After lifting it, full skids, bumpers, 35s, winch, dual batteries, etc... I had no choice but to regear. The mechanical advantage I lost with the bigger tires and all the weight I added to the Jeep would have made it almost undrivable on road and an absolute joke off road. So 4.56 gears took place of the stock 3.21 sets. Night and day! Accelerates better than stock, easier to take off from a stop, crawl speed is slower off road, and just a much more pleasurable experience to drive it altogether. While I installed the gears I slipped in a set of air lockers and some chrome-moly axle shafts. If you have 35s you need to do this!

Gussets and sleeves. Highly recommend this if you do the moderate trails you claim and have the added weight of 35" tires. The stock C on the Dana 30 and 44 are prone to flex and bending with heavier tires and moderate wheeling. If it was a mall crawler I would say forget it but if you wheel you should do this. The gusset is a 4 piece support that is welded directly to the axle and outer C. It supports the top and the bottom C casting and is fairly easy to install for the most part. The only thing I STRONGLY recommend is that you don't screw around with the stock ball joints. Just press in a new set of HD joints like Synergy's. The stock joints have plastic liners in them and all the heat of welding will cause it to deteriorate. You have it apart... just replace them. The Sleeves are a little more of a pain but a worthwhile modification as well. Basically you are pressing a tube inside your axle tube and welding them together creating a much thicker therefor stronger axle housing. To do this you need to pull the axles and drill a series of 1/2" diameter holes around the axle tubes in different locations. Drive the sleeves into the axle tubes and then weld the holes back in welding the sleeves to the axle tubes. I did this in 12 spots on the short tube and 16 on the long. This is similar in welding in an axle truss but I believe a little less effective. Certainly way stronger than stock but just my feeling that it doesn't supply as much strength as an Artec Truss. On my jeep and artec truss wouldn't clear my skids so keep that in mind.

Both of these mods, gearing and gussets/sleeves, should be done at the same time. It would be more expensive and repetitive if not done together.
 

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Discussion Starter #6
You do not need or even want a 4 inch lift for 35 inch tires, especially on a two door. A 2.5 lift will be enough.

Especially with the 3.8 engine, regearing is one of the best things you can do to your Jeep.

I did a full truss/gusset rather than sleeve since I rock crawl.
Appreciate your perspective here but can you provide more basis for your point? I currently run 33s on a 2" budget lift and when I'm rock crawling it always seems I'm at the limit. So going to 35s would require SOME amount of additional lift.
 

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To start off... 4" of lift with 35s is way to much. 2.5" - 3" will fit nicely with plenty of clearance. Any reputable manufacturers lift kit is going to gain you more than advertised. Sometimes by a significant amount depending on how the Jeep is outfitted. Plus once you hit 3.5" of lift then there is a whole boat of other mods that should be made to the suspension and steering to fix some driveability issues you will start to encounter.
So gearing is one of those mods that most people hate to do because of the expense of it but, once done kick themselves for not doing it sooner. It really is a game changer. The gearing change is in the front and rear differentials so it effects both high and low range. At minimum it gets you back the torque that you lost when you installed bigger tires but most people gear it down even further for an off road vehicle. My JK has the 3.8 and with the stock 3.21 gearing was at best a DOG. After lifting it, full skids, bumpers, 35s, winch, dual batteries, etc... I had no choice but to regear. The mechanical advantage I lost with the bigger tires and all the weight I added to the Jeep would have made it almost undrivable on road and an absolute joke off road. So 4.56 gears took place of the stock 3.21 sets. Night and day! Accelerates better than stock, easier to take off from a stop, crawl speed is slower off road, and just a much more pleasurable experience to drive it altogether. While I installed the gears I slipped in a set of air lockers and some chrome-moly axle shafts. If you have 35s you need to do this!

Gussets and sleeves. Highly recommend this if you do the moderate trails you claim and have the added weight of 35" tires. The stock C on the Dana 30 and 44 are prone to flex and bending with heavier tires and moderate wheeling. If it was a mall crawler I would say forget it but if you wheel you should do this. The gusset is a 4 piece support that is welded directly to the axle and outer C. It supports the top and the bottom C casting and is fairly easy to install for the most part. The only thing I STRONGLY recommend is that you don't screw around with the stock ball joints. Just press in a new set of HD joints like Synergy's. The stock joints have plastic liners in them and all the heat of welding will cause it to deteriorate. You have it apart... just replace them. The Sleeves are a little more of a pain but a worthwhile modification as well. Basically you are pressing a tube inside your axle tube and welding them together creating a much thicker therefor stronger axle housing. To do this you need to pull the axles and drill a series of 1/2" diameter holes around the axle tubes in different locations. Drive the sleeves into the axle tubes and then weld the holes back in welding the sleeves to the axle tubes. I did this in 12 spots on the short tube and 16 on the long. This is similar in welding in an axle truss but I believe a little less effective. Certainly way stronger than stock but just my feeling that it doesn't supply as much strength as an Artec Truss. On my jeep and artec truss wouldn't clear my skids so keep that in mind.

Both of these mods, gearing and gussets/sleeves, should be done at the same time. It would be more expensive and repetitive if not done together.
Rich, great answer. I currently am running 33s on a 1.5-2" budget lift. So you think moving up to 35s would definitely push me to regearing, if I follow you. OK.

I've always been budget limited, so I only added an Aussie locker for the front and run with the stock LSD in the back. If I go to 35s and regear, do I have to replace the current Aussie/LSD combo as well? They've served me pretty well so far. [Although I was running Odessa Canyon last weekend and my rear tires were spinning trying to get up that 5' waterfall while everyone else made it. Part of the reason was lousy spotting, but I was guessing that the stock gears didn't give me enough push either.]

Thanks for any additional perspective you might have!
 

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Rich, great answer. I currently am running 33s on a 1.5-2" budget lift. So you think moving up to 35s would definitely push me to regearing, if I follow you. OK.

I've always been budget limited, so I only added an Aussie locker for the front and run with the stock LSD in the back. If I go to 35s and regear, do I have to replace the current Aussie/LSD combo as well? They've served me pretty well so far. [Although I was running Odessa Canyon last weekend and my rear tires were spinning trying to get up that 5' waterfall while everyone else made it. Part of the reason was lousy spotting, but I was guessing that the stock gears didn't give me enough push either.]

Thanks for any additional perspective you might have!


In your reply to Mommymallcrawler you mentioned that you run a budget boost and rub on 33s. Budget Boosts add from stock hight exactly what you purchase. A 2" budget boost will give you exactly 2" from whatever stock, worn out spring height you happened to currently have. Get my point? They are cheap and get you some clearance but you can't compare them to a spring lift from a reputable manufacturer. For example.. My 3.5" Rock Krawler coils netted me 4 1/16" after bumpers, a winch and dual batteries on a hard top. Only after adding nearly 260 lbs of skids did I add 1/2" spacers to the front just to level it out again. I still netted 4" after everything was said and done.

To answer your questions... I have never wheeled with, met or even read a single forum post from someone who wasn't ecstatic about the results of a proper gearing change. Mind you the word proper. If you run 5.38s with 35" tires you will be VERY disappointed with your new found highway top speed but, you might be thrilled about your ability to rock crawl. So be honest about where you want your Jeep to perform. I went with 4.56s in mine. It is a true dual purpose rig. I drive to where I wheel and I need it to perform well off road. I have a 3.8L and 6 speed. 40 is about 2000 rpm in 4th and 70 is 2300 rpm in 6th. I drive 70 - 75 tops on the highway. Any more than that I start feeling bad for the 3.8 but it works well off road as well with plenty of torque getting to the wheels and I'm not abusing the clutch through obstacles. For me it works well.
You shouldn't have to replace the Aussie or the rear lsd. I might recommend you just throw the Aussie in the rear too if your budget minded. It will certainly perform better off road which you already know. What you will have to do most likely is replace the front carrier if you have 3.21 gears. You will need a carrier for 3.73s and numerically taller gearing. The carrier is about $80 so not bad and you can transfer the Aussie into it.

It's a big chunk of change I know. Luckily I do my own swaps but it still would be $800 in parts, odds and ends for even the most budget of a swap. Add $1000 worth of axles, $1600 for air lockers, $250 for ball joints, $250 for gussets and sleeves, and $500 for my ARB air pump and wow.. That's a lot of $$$! Put labor on top of that and I don't know if even I would have spent that money. Run more than 3" - 3 1/2" lift then possibly run into drive shaft issues, adjustable control arms, high steer upgrades, adjustable track bars with raised axle side mounts, etc... It just gets ridiculous! I don't even want to know what I have invested in the front end and suspension of my JK.

FYI... I have a couple friends that wheel with 37" tires. 1 has a 2.5" Teraflex lift and the other a 2.5" MetalCloak lift and flat fenders. They installed flat fenders and do not rub at all. Low center of gravity, great articulation and those 37s really help bump over obstacles. One runs 4.88 gears and the other runs 5.13s. The guy with the 5.13 trailers when their is alot of highway. Of course they both have aftermarket Dana 44s as well.... It never ends!
 

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Discussion Starter #9
I have never wheeled with, met or even read a single forum post from someone who wasn't ecstatic about the results of a proper gearing change. Mind you the word proper. If you run 5.38s with 35" tires you will be VERY disappointed with your new found highway top speed but, you might be thrilled about your ability to rock crawl. So be honest about where you want your Jeep to perform. I went with 4.56s in mine. It is a true dual purpose rig. I drive to where I wheel and I need it to perform well off road. I have a 3.8L and 6 speed. 40 is about 2000 rpm in 4th and 70 is 2300 rpm in 6th. I drive 70 - 75 tops on the highway. Any more than that I start feeling bad for the 3.8 but it works well off road as well with plenty of torque getting to the wheels and I'm not abusing the clutch through obstacles. For me it works well.

You shouldn't have to replace the Aussie or the rear lsd. I might recommend you just throw the Aussie in the rear too if your budget minded. It will certainly perform better off road which you already know. What you will have to do most likely is replace the front carrier if you have 3.21 gears. You will need a carrier for 3.73s and numerically taller gearing. The carrier is about $80 so not bad and you can transfer the Aussie into it.
Rich:

Some late followup to your points here. I went on a weekend with WF and for the first time needed a tug up a 4-foot rock waterfall. It perplexed me that I didn't get up it.

First, clarify for me. If I regear, from the stock JK gearing which I currently have, will I have more power for rock crawling? And will the higher the gearing the better crawl capability? I ask you this because a mechanic I know said that regearing only impacts highway and street driving.

Second, if I swap out the rear LSD for a rear Aussie, so that I now have Aussies in front and back, will this too help me with rock crawling?

Tom
 

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Appreciate your perspective here but can you provide more basis for your point? I currently run 33s on a 2" budget lift and when I'm rock crawling it always seems I'm at the limit. So going to 35s would require SOME amount of additional lift.
You gotta think about physics too. A 2-dr with a shorter wheelbase is going to be at higher risk of tipping or rolling the higher you lift up there.

And if it's clearance you're after, your pumpkin stays the same height whether you have no lift or 6" of lift. Your tires dictate axle clearance.

4" is really overkill unless you are dumping $10K+ into making this thing a competition crawler. Throw in a 2.5" Teraflex coil lift and call it a day. :)
 

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3" mopar lift for a 4 door.

about 5" of actual lift. Probably 4" on a rubicon.


Point is its pretty freaking beast with 35's. Plus I like to know that if i hit the lottery 37s and a HD front axle are a few bolts away :)
 

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If you are going to be rock crawling, I would lose the Aussie and LSD for ARB air lockers or selectables.

I clear perfectly 37 inch tires on 2.5 inches of lift with flat Fenders and a little trimming. I would not want 4 inches or 5 inches lift on stock axles - too unstable, crappy drivetrain geometry. Two doors benefit way more from LCOG lifts - just enough to clear the tires and without having to ridiculous bumpstop to limit travel.

You could run 35s with flat Fenders and a 1.5 lift.
 

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Rich:

Some late followup to your points here. I went on a weekend with WF and for the first time needed a tug up a 4-foot rock waterfall. It perplexed me that I didn't get up it.

First, clarify for me. If I regear, from the stock JK gearing which I currently have, will I have more power for rock crawling? And will the higher the gearing the better crawl capability? I ask you this because a mechanic I know said that regearing only impacts highway and street driving.

Second, if I swap out the rear LSD for a rear Aussie, so that I now have Aussies in front and back, will this too help me with rock crawling?

Tom



Lower gearing will help your ability to crawl slower and put more torque to the wheels. It won't make the same difference as say a transfer case with a 4:1 low range ratio like the Rubicon cases have but you will notice a definite difference.
Locking the front and back makes a huge difference off road as you know. You can go with an Aussie in the rear but you will have to modify your driving style a little. When on the gas going around corners (like pulling out of side streets) it will want to lock up the rear. You may want to consider an e-locker if the funds are available in the rear instead.
 

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For what it's worth I just got done with a regear sleeve and gusset front locker heavy ball joints and adjustable control arms. I run 35x12.50 tires. I wheel about 25% of the time and stick to moderate what I call sightseeing trails. I don't beat on my current rig. No rock bouncing or attacking trails aggressively. Jeep only had 12,000 miles on it when gears were replaced. I helped my installer do the entire job and he said my front tube on the long side was most likely a little bit bent. The sleeves are supposed to be a nice snug tap em in with a hammer kind of fit, we had to press them in with a hydraulic press set up he had in his shop. All that to say at the very least I would sleeve an axle any day but had I known then what I know now I would have done a truss most likely. The gears are so worth it. Jeep doesn't struggle at all anymore. Feels lighter and more eager to get up hills or over obstacles. I haven't been off road with it yet but I'm shooting to hit a trail this weekend.
 

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It's a big chunk of change I know. Luckily I do my own swaps but it still would be $800 in parts, odds and ends for even the most budget of a swap. Add $1000 worth of axles, $1600 for air lockers, $250 for ball joints, $250 for gussets and sleeves, and $500 for my ARB air pump and wow.. That's a lot of $$$! Put labor on top of that and I don't know if even I would have spent that money. Run more than 3" - 3 1/2" lift then possibly run into drive shaft issues, adjustable control arms, high steer upgrades, adjustable track bars with raised axle side mounts, etc... It just gets ridiculous! I don't even want to know what I have invested in the front end and suspension of my JK.
!
I am looking forward, next year I will be upgrading to 37's. When I was a jeep beach and talked to the guy at the Core 44 booth about trussing and sleeving - he suggested I just keep my current set up till I break it or wear it out then upgrade to a Rock Jock, Core 44 or Dynatrac.

Whats your thought on this... above you detailed a pretty expensive list. I was thinking even if you had the front axle speced out and cost was around 4K then I could sell my stock D44 or around 1800 or so...

thoughts???

Didnt want to invest money into my current 44 then wished i had the upgraded 44
 

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I am looking forward, next year I will be upgrading to 37's. When I was a jeep beach and talked to the guy at the Core 44 booth about trussing and sleeving - he suggested I just keep my current set up till I break it or wear it out then upgrade to a Rock Jock, Core 44 or Dynatrac.

Whats your thought on this... above you detailed a pretty expensive list. I was thinking even if you had the front axle speced out and cost was around 4K then I could sell my stock D44 or around 1800 or so...

thoughts???

Didnt want to invest money into my current 44 then wished i had the upgraded 44
Jealous of 2 things here. First, I would of loved to have gone to Jeep beach... Second, I wish I did all that work to a 44! I have a 30:jawdrop:
I guess it comes down to this. If you plan on doing the Rock Jock, Core 44 or whatever aftermarket axle no matter what in the future then don't waste a dime in the stock one. I did the work that I did to mine for two reasons. I don't want to replace my front axle so I have made an attempt to make it as bullet proof as I can and second, the type of wheeling I do doesn't necessitate that I have a beefier front axle. I don't spend my life in rock gardens or the Rubicon Trail.
Now... if I had your 44 and wanted a reliable front axle for a set of 37" tires and some moderate wheeling I would truss and gusset the stock axle, slide some chrome-moly shafts in it, a HD diff cover, a 1350 Tom Woods drive shaft (either way you will do that), set of HD ball joints and go. I think it would hold up just fine. And if it didn't then you really wanted a 60! The one thing you may miss is some caster correction that aftermarkets can be built with. But... if you're going to swap in the Rock Jock anyway then all that is a big waste.
 
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