2002 commuter re-gear / build question

jkosten

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Hello all,

I have been looking through the forums to help guide my regearing decision and I want confirm some thoughts. I drive 4 miles to work and 1 mile to my son's school all in town under 35mph, and this is my 4th vehicle, not exactly my daily driver but better for short in town trips vs my diesel truck.

I have a 2002 123k miles Sahara 4.0 NV3550 NP231 Dana 30 / 44 (3.73) 3" coils 33" tires. I do not plan on increasing the tire size unless axle upgrades are made (Swap?)

Currently while driving it seems like the gears are too tall and for my mostly in town driving it just isn't great. I am trying to keep my rpm between 2k and 3k for most driving as to not lug the engine (I cannot which thread I read that in). I end up running 1st gear to 20 mph and 2nd to 35mph. In traffic it is hard to creep in 1st. I can comfortably drive on the highway in 4th gear at 60-65mph. I also do not see a need to do 108mph at 3k rpm in a solid brick.

I am considering going 4.56 to get a more comfortable city driving and I am not sure how much dirt this will see (but I don't want it to not be able to go off highway if needed). Or should I just go to 4.88? I like the idea that with 4.56 I get to 65mph in 4th without an upshift. That would match a lot of highway driving that is 55-65 mph.

Charts for reference

3.73 Gear Ratio
1672453721415.png


4.56 Gear Ratio
1672453689340.png


4.88 Gear Ratio
1672455021777.png


The second part of the problem is: If i am going to regear, what traction aids do I add?

Reading Locker advice and re-gearing and Wavetrac differential for Dana 30 (plus others) I am leaning towards a front Spartan Locker and rear Truetrac. I was originally thinking Torsen LSD front and rear (my Dodge has a factory one in my AAM axle), but the conversations in those other threads offered justification to better front traction if needed in 4wd, without compromise to 2wd (yes the Powertrax No-Slip would be quitter, but I am not worried).

IF I ended up in the snow (Oregon or Tahoe area) would a front Locker be hard to drive / steer on highway in 4h?

I also know that most people end up putting a selectable rear locker in, but not sure I want to send that much (but would I regret that in 4-6 years?) or how annoying would an Powertrax No-Slip be in the rear? (and then I would match to the front).

Current shopping list: (approximately $1600 on Amazon with Prime)

US Standard Gear 4.56 kits for Dana 30 and Dana 44
US Standard Gear Master overhaul kits for Dana 30 and 44
US Standard Gear Dana 30 Spartan Locker
Eaton Detroit Truetrac Dana 44
7 Spicer u-joints (stock ones)

And all the install labor would be myself (I have a full shop available: I am a Master ASE Auto and Diesel tech / Instructor)

1672452470137.png


1672452508735.png
 

eastbloc

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This is the only place i have ever seen that makes rocket science out of shifting and engine lugging....
Base on the picture you have painted, seems like simply going down in tire size will fix all your issues, for a fraction of the cost. Im also failing to see what situations pushed you towards traction aids?
What IF your Jeep is good as is for every IF that you will ever run into...IF? Another case of backwards thinking.
 

AndyG

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Well- I’ve got the same transmission with 4:56 years and 33 inch tires and I’m gonna give you my take about all these gearing computations:

Get @Jerry Bransford on here, and gear it to what he says. And he will say 4:88.

The reason I say that is real world experience means everything and I understand looking at the charts helps you to get an idea of what’s going to happen but what’s the charts don’t factor in is -

- passengers

- weight of aftermarket accessories, winches and hard top, armor and hi lift jacks,etc.

- aerodynamics

- harder to roll stiff tires, beadlocks and tire weight

- hills /Inclines

- type of road surface

4:56 will get the job done in perfect conditions, but 4:88 will get it done better in all conditions.

Yes, this is a shameless nod to Jerry, but you have to give credit where credit is due. At least that’s what I was trying to convince my banker of recently.
 

Rickyd

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You didn't enter 33" as the actual tire diameter for those calculations
right? Most tires are smaller than advertised.might want to verify that with a gps app on your phone.

4.88/33s would be very peppy with a 6. But probably get old fast on the freeway to me.are you going to trailer it to oregon and tahoe?As far as snow i bet some chains would be better than lockers if money is tight. Then your braking would also improve.

For my money I'd only ever install selectible lockers. Spending money on less is a waste to me.lunchbox lockers were cool as a broke kid. Not so much now.

I live an hr north of you.i know that area well. You'll be happy with 4.56 if you wind up taking trips on 101 or 5
 
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jkosten

jkosten

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You didn't enter 33" as the actual tire diameter for those calculations
right? Most tires are smaller than advertised.might want to verify that with a gps app on your phone.

4.88/33s would be very peppy with a 6. But probably get old fast on the freeway to me.are you going to trailer it to oregon and tahoe?As far as snow i bet some chains would be better than lockers if money is tight. Then your braking would also improve.

For my money I'd only ever install selectible lockers. Spending money on less is a waste to me.lunchbox lockers were cool as a broke kid. Not so much now.

I live an hr north of you.i know that area well. You'll be happy with 4.56 if you wind up taking trips on 101 or 5

I used 33 since both the current tires measured 32.8 and the Yokohama Geolander or Toyo RT run at almost 33.

I could just regear now, and add selectable lockers when I actually have a planned need for them.

Only reason for try to save money is this supposed to be a budget friendly (according to my wife) project.
 
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jkosten

jkosten

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Well- I’ve got the same transmission with 4:56 years and 33 inch tires and I’m gonna give you my take about all these gearing computations:

Get @Jerry Bransford on here, and gear it to what he says. And he will say 4:88.

The reason I say that is real world experience means everything and I understand looking at the charts helps you to get an idea of what’s going to happen but what’s the charts don’t factor in is -

- passengers

- weight of aftermarket accessories, winches and hard top, armor and hi lift jacks,etc.

- aerodynamics

- harder to roll stiff tires, beadlocks and tire weight

- hills /Inclines

- type of road surface

4:56 will get the job done in perfect conditions, but 4:88 will get it done better in all conditions.

Yes, this is a shameless nod to Jerry, but you have to give credit where credit is due. At least that’s what I was trying to convince my banker of recently.

Thank you, and why I wanted to ask first, not after trying it.
 
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jkosten

jkosten

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New tires are $1000+ and it would look odd having 3" coils plus 30" tires. Plus my Wife likes the current look of the Jeep compared to the "stock" ones driving around.

Happy wife? Happy budget?

I am used to driving in the power zone of diesels: 1700 to 2400 rpm, or automatics that manage torque for you.
This is the only place i have ever seen that makes rocket science out of shifting and engine lugging....
Base on the picture you have painted, seems like simply going down in tire size will fix all your issues, for a fraction of the cost. Im also failing to see what situations pushed you towards traction aids?
What IF your Jeep is good as is for every IF that you will ever run into...IF? Another case of backwards thinking.
 

Rickyd

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Well- I’ve got the same transmission with 4:56 years and 33 inch tires and I’m gonna give you my take about all these gearing computations:

Get @Jerry Bransford on here, and gear it to what he says. And he will say 4:88.

The reason I say that is real world experience means everything and I understand looking at the charts helps you to get an idea of what’s going to happen but what’s the charts don’t factor in is -

- passengers

- weight of aftermarket accessories, winches and hard top, armor and hi lift jacks,etc.

- aerodynamics

- harder to roll stiff tires, beadlocks and tire weight

- hills /Inclines

- type of road surface

4:56 will get the job done in perfect conditions, but 4:88 will get it done better in all conditions.

Yes, this is a shameless nod to Jerry, but you have to give credit where credit is due. At least that’s what I was trying to convince my banker of recently.

This is absolutely right. Theres more too it than gear charts.gearing to go back to stock ratio leaves out all of the above,especially if you had the aweful 3.07 gears.

But you saying "I am not sure how much dirt this will see (but I don't want it to not be able to go off highway if needed" is what makes me suggest 4.56 gears. 33/4.56 is a great all around combo with the least compromise.you'll be perfectly capable of smashing it on rocks with 4.56 in low range.

Are you going to put a bunch of steel armor on it and load it down for trips?
 
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jkosten

jkosten

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This is absolutely right. Theres more too it than gear charts.gearing to go back to stock ratio leaves out all of the above,especially if you had the aweful 3.07 gears.

But you saying "I am not sure how much dirt this will see (but I don't want it to not be able to go off highway if needed" is what makes me suggest 4.56 gears. 33/4.56 is a great all around combo with the least compromise.you'll be perfectly capable of smashing it on rocks with 4.56 in low range.

Are you going to put a bunch of steel armor on it and load it down for trips?

Probably not, I take my Dodge Megacab for trips (plus wife, 4yr old and Labrador). Other than being a long wheel base, it goes any where I am willing to take it with only a rear Torsen (but plenty of power to pull through issues, like sand if aired down) (side note, always air down for sand)

So any dirt time would be relatively local to northern CA.
 

Old Pueblo

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My situation was a little different, because I have the 42 RLE. I went 4.88 with 33's and it was just OK. Hindsight being 20/20, I should have gone to 5.13. When I went to 35's, 4.88 sucked.. Constantly hunting gears, etc. I recently went to 5.38 and it's perfect.
 
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jkosten

jkosten

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My situation was a little different, because I have the 42 RLE. I went 4.88 with 33's and it was just OK. Hindsight being 20/20, I should have gone to 5.13. When I sent to 35's, 4.88 sucked.. SUCKED!! I recently went to 5.38 and it's perfect. Yes, perfect.

So you still have the 4.88 gears in a box?
 

Old Pueblo

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So you still have the 4.88 gears in a box?

No. I gave away my front Dana 30, and didn't keep my rear gears, carrier or axles. I would have given them to you.
If your rig was mine, and I planned on staying on 33's, I would likely go 4.88.... Or 5.13.. LOL.. For sure it wouldn't be 4.56
 
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MikekiM

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I just went through this a few months ago.

2000 with 4.0, NV3550, 33's.. My daily driver that sees light off-road on mostly outer beach sand, dirt & rock fire roads to and from backpacking basecamp. I do about 40 miles to and from work. Had 3.73's stock.
I have no intention of going bigger than 33's.

I did 4.56's and I have to say it is dead perfect for a DD. Zero regrets. Pulls hard no matter where I am in the torque curve. Every upshift seems to land at the right rpm and down shifts take just a light throttle blip to rev-match. Easily my favorite mod and the one that had the single greatest impact on drivability and enjoyment.

I did Detroit TrueTrac limited slips at the same time. Virtually invisible during everyday driving unless I mash the loud pedal in a low traction situation.

Pretty much a perfect mod for my use-case.
 
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Jerry Bransford

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Hello all,

I have been looking through the forums to help guide my regearing decision and I want confirm some thoughts. I drive 4 miles to work and 1 mile to my son's school all in town under 35mph, and this is my 4th vehicle, not exactly my daily driver but better for short in town trips vs my diesel truck.

I have a 2002 123k miles Sahara 4.0 NV3550 NP231 Dana 30 / 44 (3.73) 3" coils 33" tires. I do not plan on increasing the tire size unless axle upgrades are made (Swap?)

Currently while driving it seems like the gears are too tall and for my mostly in town driving it just isn't great. I am trying to keep my rpm between 2k and 3k for most driving as to not lug the engine (I cannot which thread I read that in). I end up running 1st gear to 20 mph and 2nd to 35mph. In traffic it is hard to creep in 1st. I can comfortably drive on the highway in 4th gear at 60-65mph. I also do not see a need to do 108mph at 3k rpm in a solid brick.

I am considering going 4.56 to get a more comfortable city driving and I am not sure how much dirt this will see (but I don't want it to not be able to go off highway if needed). Or should I just go to 4.88? I like the idea that with 4.56 I get to 65mph in 4th without an upshift. That would match a lot of highway driving that is 55-65 mph.

The second part of the problem is: If i am going to regear, what traction aids do I add?

Reading Locker advice and re-gearing and Wavetrac differential for Dana 30 (plus others) I am leaning towards a front Spartan Locker and rear Truetrac. I was originally thinking Torsen LSD front and rear (my Dodge has a factory one in my AAM axle), but the conversations in those other threads offered justification to better front traction if needed in 4wd, without compromise to 2wd (yes the Powertrax No-Slip would be quitter, but I am not worried).

IF I ended up in the snow (Oregon or Tahoe area) would a front Locker be hard to drive / steer on highway in 4h?

I also know that most people end up putting a selectable rear locker in, but not sure I want to send that much (but would I regret that in 4-6 years?) or how annoying would an Powertrax No-Slip be in the rear? (and then I would match to the front).

Current shopping list: (approximately $1600 on Amazon with Prime)

US Standard Gear 4.56 kits for Dana 30 and Dana 44
US Standard Gear Master overhaul kits for Dana 30 and 44
US Standard Gear Dana 30 Spartan Locker
Eaton Detroit Truetrac Dana 44
7 Spicer u-joints (stock ones)

And all the install labor would be myself (I have a full shop available: I am a Master ASE Auto and Diesel tech / Instructor)
4.56 is the right ratio for your 33" tire size and 5-speed. Don't even consider 4.11 for 33's. Your rear Dana 44 and front Dana 30 are both definitely up to 35's, I ran 35's on that combination of axles for years. I'd only upgrade the Dana 30's axle shafts to chromoly for 35's and locker. For 35's I'd go 4.88 though 5.13 would be a great choice if you make drives up into the mountains much. 4.88 worked fine for my mountain needs for my 35's but so many likely 5.13 that it would clearly be a great choice too if you get into mountainous areas much.

If you're going to install a locker in the rear axle, avoid any lunchbox locker, they are all very poorly behaved when in the rear axle. They're fine in the front, not in the rear. For the rear, since you occasionally see snow or ice I'd definitely go for a selectable locker like an Eaton E-Locker (less expensive) or ARB Air Locker (more expensive). A lunchbox locker is fine up front and they don't affect steering when you're in 2wd. But if you shift into 4x4 like on an icy road or icy trail your steering would be tough/nearly ineffective. Which just boils down to selectable lockers being the right choice if you have to drive on icy or snow covered surfaces.

The Detroit Truetrac is superb on slicky/icy surfaces but it sucks and doesn't do much, if anything at all, to help on trails that are uneven enough to lift a tire up into the air. I replaced both of my Truetracs with lockers since my trails are uneven and almost never icy.
 

L J

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I'd start my own thread asking the question as you may get more replies but ...

Yukon would be towards the bottom of my list for a gear supplier. I believe they source their gears from China. I have no empirical evidence to show that they are shit gears but it's not something I want to chance. Revolution Gear and Axle at the top. Other suppliers who source gears from the Circle K factory in South Korea would follow Revolution.
 
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06lj

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I just ordered Nitro gears as Revolution is out of stock for the ratio I need and has been for a couple if years now (HP Dana 30 5.13). They seem to be well regarded in the Toyota world and I found several reviews claiming they set up better than the Yukons. They used to specify that their gears were made in Korea but that seems to have been removed from their website. Many vendors still list the country of origin as Korea. I guess I'll be finding out in the next few weeks. However, if your not doing the gears yourself just go with a reputable shop that warranties their work and use their preferred brand.
 

Modoc Guy

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My ‘02 is an automatic with a 3” lift and your size tires. I went with 4:10’s for the automatic, and it put engine rpm’s back in the stock range for street driving. And it also works well off road.

With the stick, I think you’d be better off with the 4:56’s as Jerry and others have suggested. Unless you’re ok with higher rpm’s at freeway speeds, and the lower mileage that might come with it.

I came to my build decision after listening to the forum. But I took a long time weighing the info so I’d make sure that the decision I made wouldn’t bite me in the ass and my wallet later! 😸