Need new Gears

[freebird2]

I'm about to get bigger tires either 33" or 35" probably going with the bfg KM2 or the Trxus Intercos not sure yet. So, I've got Dana 30 3.73 in the front and Dana 44 3.73 in the rear. With larger tire I'm considering going with the 4.88 gear ratio to save power. Now what parts and pieces am I looking for to make this conversion a complete success. Does anyone know a good gear man in the south GA, North Florida area?

 

[Bounty__Hunter]

4.88 is a good choice. Check out Welcome to Complete Off Road for great prices on gears and install kits. Make sure the d30 kit is low pinion, or standard rotation.

 

[jtjwrangler]

Just be easy on the dana 30 so you dont break it. They dont like tires over 33". Consider up graded axles in the future.

 

[Utah_jeepster]

Your gears, and master install kit should run along the lines of about 280$ per axle, depending on what brand you buy. Once you change from 3.73 to any thing over 3:93 (ie 4:10-4:88) your going to have to change carriers. That means anything from 200$ to 1000$ more per axle depending on what traction device you decide on.

The Dana 30 axle is a weak axle but not as bad as the Dana 35. Many here will tell you they have wheeled on a Dana 30 with 33 or 35 inch tires for years with no problems. Some will say there no good. Personally I still run a Dana 30 front axle, but I did up grade the axles to 30 spline and chromoly shafts. It was worth the added expense than finding a Dana 44 front and having it cut down at the time.

Either way most shops charge around 200-250$ per axle to install the gears and more if your changing to over sized axle shafts, since they have to R&R the bearings and axle seals.

 

[freebird2]

4.88 is a good choice. Check out Welcome to Complete Off Road for great prices on gears and install kits. Make sure the d30 kit is low pinion, or standard rotation.

how do I find out if its low pinion or standard rotation? What will this tell me?

 

[freebird2]

Your gears, and master install kit should run along the lines of about 280$ per axle, depending on what brand you buy. Once you change from 3.73 to any thing over 3:93 (ie 4:10-4:88) your going to have to change carriers. That means anything from 200$ to 1000$ more per axle depending on what traction device you decide on.

The Dana 30 axle is a weak axle but not as bad as the Dana 35. Many here will tell you they have wheeled on a Dana 30 with 33 or 35 inch tires for years with no problems. Some will say there no good. Personally I still run a Dana 30 front axle, but I did up grade the axles to 30 spline and chromoly shafts. It was worth the added expense than finding a Dana 44 front and having it cut down at the time.

Either way most shops charge around 200-250$ per axle to install the gears and more if your changing to over sized axle shafts, since they have to R&R the bearings and axle seals.

What is the traction device for and what are the different types? what does the different spline count and chromoly shafts do?

 

[jtjwrangler]

how do I find out if its low pinion or standard rotation? What will this tell me?

Look at your axle. The drive shaft should be above the centerline of the axle (high pinion) or below the center line of your axle (low pinion). The high pinion gears have a reverse rotation and the low pinion have a standard rotation. They are two different gears sets.

 

[jtjwrangler]

What is the traction device for and what are the different types? what does the different spline count and chromoly shafts do?

Traction devices are lockers or limited slips. They put power to both wheels instead of the one with the least amount of traction (open diff). For the spline count the more the better. The splines are the teeth on the end of the axle that goes into the carrier (traction device). The more splines the more surface area that comes into contact making it stronger. Chromoly shafts (chromos) are a stronger material that the axles are made out off. They have great characteristics. They will twist up 360 degrees before breaking. Stock axles dont like to twist. So if you have your tires binded up on some rocks and stomp on the skinny pedal the chromos will hold up alot longer under that abuse. There are some companys that will sell you a complete axle with your chose of gear ratio, traction device, and spline count with chromo shafts. They cost alot but could be cheaper than getting all of these parts and paying someone to install them and hope they do a good job.

 

[RDPrimeaux]

with an auto, and if you have any intention of going with 35's, go with the 5.13 gears. The overdrive gear on the auto is super high.

 

[Bounty__Hunter]

with an auto, and if you have any intention of going with 35's, go with the 5.13 gears. The overdrive gear on the auto is super high.

He is limited to 4.88 in the d30 front axle, can't go lower. The TC in the auto multiplies torque so a super deep axle gear isn't really needed.

All TJ front axles are low pinion, unless a HP d30 from an XJ is swapped in.

 

[freebird2]

Are you sure I'll need new carriers? And what are some different carriers and what does a locker do for you and should I get lockers?

 

[jtjwrangler]

I installed 4.56 gears in my tj with out changing carriers. They might have a set of thick gears that will work. When you order your gears just ask them about to carrier. They should be able to let you know for sure.

 

[Bounty__Hunter]

Are you sure I'll need new carriers?

You do NOT need a new carrier for the D30, carrier break is 3.54/3.73, which means 4.56 and 4.88 use the same carrier as your 3.73 gears.

The carrier break on your d44 rear is 3.73/3.93 so you WILL NEED a new carrier to go lower than 3.73 such as 4.56 or 4.88.

 

[Bounty__Hunter]

Gears, Lockers and Install Kits - Dana 44 is a link to a great affordable supplier of gears, differentials, and assorted drivetrain parts. That page has 'thick' gearsets in 4.56 and 4.88 that will allow you to use your original d44 carrier, so no new carriers are needed.

 

[jfrabat]

With the "open differential" (which is what comes with the Jeep), both wheels can turn at different speeds so that you can take corners easily. The downside of this is that if you raise one of your rear wheels off the ground, and have the Jeep in 2WD, the Jeep will not move because all the power will be sent to the wheel with the least resistance (in this case, the wheel that is off the ground will spin fast, while the one on the flor -ie. the one with the traction - will not spin at all).

While an open differential is fine for street driving, but for offroad, it sucks because the power will always be sent to the wheel with the LEAST traction, which means you are very likely to get stuck if you loose some traction.

The other extreme is the spool, where both the right and left wheel turn at the same time because the right side and left side of the axle are bounded together. This is great for offroad, because power is always transfered 50/50 to each side, but sucks for street because it is a pain to take corners.

If you want the best of both worlds, you get a locker (like OX, which is cable actuated, or ARB which is air actuated). What these do is that when activated, they act as a spool, but when not actuated they act like open differentials.

THere are other options but if you really want the best of both worlds, I recommend a locker... As for the other options, the most common is the limited slip differential, which will not allow 100/0 split of power, so it always send SOME power to both wheels (although if you loose traction, you will have less than 50% of power to the wheel with the traction). There are also some automatic lockers, like the detroit lockers which are popular, but for street driving, they make a bit of noise.

With lockers, you will not notice them when they are off, but when you need them, they will send power to the wheels. Personally, I prefer the ARB because an electrical switch is easier to install than a lever in the cab of the Jeep (on the down side, they do require that you install a compressor on board to activate them), but I have heard no bad comments about the OX (just amke sure the cable is set up properly and they will work whenever you need them).

Felipe

 

[freebird2]

Has anyone hard anything about the Aussie lockers? I've only read one review.

 

[Smackdaddy]

Man look at all this stuff!!! I am beginning to wonder if this is all as easy as just ordering the kit off Quadratec ortaking the rig to a professional shop and letting them rip you a new one on the parts? How do you know which axels your ride came with stock? Mine is a 95 TJ with 4.0 engine. I am needing another 2.5 inch of clearance to make my tire combo work without rubbing the fenders. Love to go get muddy but dont really get into situations where I would need to go stronger on axels or splines etc. If I was rock climbing or getting crazy I might consider the extras. Any thoughts?

 

[Bounty__Hunter]

'95 is a YJ and came from the factory with D30 front and D35 rear axles.

How much lift do you have now? What size tires now and what are you wanting to run?

 

[Utah_jeepster]

Man look at all this stuff!!! I am beginning to wonder if this is all as easy as just ordering the kit off Quadratec ortaking the rig to a professional shop and letting them rip you a new one on the parts?

If your not certain how to re-gear an axle its better to let a drive line shop do the work, Most places charge any where from 250$ for re-gearing to 500$ for re-gearing and locker/ axle replacement. Thats worth it, it takes me 8-10 hours to do an axle/ carrier/ re-gearing, inside our garage with all the tools needed, so I am sure a pro shop can cut a couple of beer hours off of that.

Love to go get muddy but dont really get into situations where I would need to go stronger on axels or splines etc. If I was rock climbing or getting crazy I might consider the extras. Any thoughts?

Mudding is just as hard on an axle as is rock crawling, any time you increase tire size or get tire slippage, then sudden traction or both, your putting just as much or even more than normal torque into your components than someone like me who plays strictly on rocks where tire slippage to complete lock up is normal. Grenading a U-joint and or yoke is expected and we carry several replacements just for that. Its whats your driving on that breaks parts, whether its when your spinning those monster mudders throwing wet soupy mud or chirping your ultra-sticky tires on solid granite. Each one adds a lot of rotational torque to your drive lines and axles, and its that torque that finds the weakest spot and breaks.
Also everything we add on to our jeeps adds stress to the axles, that 200lbs winch, the 100lbs aftermarket bumper, rims and tires, lifts.

The stock axles and gears are set for factory tire size and weight. When we start changing things we add the risk of breaking something. Axles, U-joints, and drive line components are the weakest link in the beginning as the first thing most people do are changing tire size and adding a lift to fit those tires.

The more we take our jeeps out there testing what trails we can do, sooner or later your going to break something in this category, the question is do you up-grade now guessing you might break it or wait to break it on the trail?

 

[Smackdaddy]

Man it just gets more complicated . . Love it though. I bought this jeep not only for something to have fun in but to have fun working on and making a solid ride out of for my son who is turning fifteen. I have one year to get it ready for use by a highschooler!! Better do it all the way I guess. I remember what an idiot I was when I got my first car. What to do first is my next question. I already have the tires. Most cosmetic stuff was already done as far as double bumpers front and back and nerf bars etc. I need to focus on the driveline and suspension I guess since I already have bigger tires than my lift will really allow comfortably. Should I go ahead and get the additional lift and then concentrate on the axels? Right now except for the K&N indiction box and high output coil I am bone stock. 3 inch body lift is all that is on there aside from the 33X12.5 Super Swampers. Sits fine but going down the road I can hear it rubbing on the plastic fenders. I would assume with a 2.5 suspension lift I will get the original curve back into the leaf springs plus the 2.5 inches additional curve height and should have plenty of room for the tires I am running . . . right?