Recommended re-gear for 31" tires?

[AndyG]

By and large gearing to anything below 4:10 is not regearing..... It is wasting about $1,500 or more. To regear correctly is to regear (was that @Jerry Bransford or Shakespeare?)

I'm not trying to come across like a know-it-all.. but I take this viewpoint about gearing-

A stock TJ did not come with the wrong tires or the wrong gears for those tires... It came with the tires they designed it for and the gears that are appropriate for that size tire and transmission .

When you change tire size, you do not want to have the goal of just changing something with the gearing, what you want to do is correct the change you just made to the final drive ratio with the bigger tires....or even improve on that slightly ( and I say that because not only are the tires bigger but they are also heavier so if you gear to 4:88 vs 4:56 it helps you with that aspect as well, a 12.5 x 33" on a beadlock is 2- 2.5 times heavier than a stock 31 on a stock rim maybe.) This is why the statement , given two close ratios , go with the higher second number, makes good sense.

If you want power similar to stock, and who on earth doesn't want at least that , you want to gear correctly.

People treat it like it's a preference , but from a mechanical standpoint , it's really not so much ....do you pick up a 5/8 wrench for 1/2 nut? No.

Gearing isn't a mod or a hop up , it's a correction to make the vehicle perform as designed, because the big tires changed the final drive ratio.

This is why we started the Forum Regearing Committee , which is still considered essential under Covid 19 guidelines, and still meets quarterly.

 

[CLE1998]

By and large gearing to anything below 4:10 is not regearing..... It is wasting about $1,500 or more. To regear correctly is to regear (was that Bransford or Shakespeare?)

I'm not trying to come across like a know-it-all.. but I take this viewpoint about gearing-

A stock TJ did not come with the wrong tires or the wrong gears for those tires... It came with the tires they designed it for and the gears that are appropriate for that size tire and transmission .

When you change tire size, you do not want to have the goal of just changing something with the gearing, what you want to do is correct the change you just made to the final drive ratio with the bigger tires....or even improve on that slightly ( and I say that because not only are the tires bigger but they are also heavier so if you gear to 4:88 vs 4:56 it helps you with that aspect as well, a 12.5 x 33" on a beadlock is 2- 2.5 times heavier than a stock 31 on a stock rim maybe.) This is why the statement , given to close ratios , go with the higher second number.

If you want power similar to stock, and who on earth doesn't want at least that , you want to gear correctly.

People treat it like it's a preference , but from a mechanical standpoint , it's really not so much ....do you pick up a 5/8 wrench for 1/2 nut? No.

Gearing isn't a mod or a hop up , it's a correction for messing with the factory set up you need to do to make the vehicle perform as designed.

This is why we started the Forum Regearing Committee , which is still considered essential under Covid 19 guidelines, and still meets quarterly.

Makes perfect sense and is the exact reason that I want to regear. Of course, being a newbie when it comes to Jeeps and car modification/changes in general - I wanted to get the opinion and advice of people that have done it before. I’ve read a lot of other forums where people say it’s a waste of money, but I care about my Jeeps performance and want to do things the right way.

Having said that, if I end up changing my springs along with my shocks.. would a 1 inch suspension lift make sense? I read @Chris guide to lifts and I think he said for one inch lift you only need springs/shocks/stoppers? Of course, I would still be keeping the 31s and 4.10 regear but I figured maybe this would give the tires a little more space. Also, does a lift like this have any effect on overall car performance? I assume I does at least a little..

 

[Chris]

Makes perfect sense and is the exact reason that I want to regear. Of course, being a newbie when it comes to Jeeps and car modification/changes in general - I wanted to get the opinion and advice of people that have done it before. I’ve read a lot of other forums where people say it’s a waste of money, but I care about my Jeeps performance and want to do things the right way.

Having said that, if I end up changing my springs along with my shocks.. would a 1 inch suspension lift make sense? I read @Chris guide to lifts and I think he said for one inch lift you only need springs/shocks/stoppers? Of course, I would still be keeping the 31s and 4.10 regear but I figured maybe this would give the tires a little more space. Also, does a lift like this have any effect on overall car performance? I assume I does at least a little..

A 1" lift is so minimal that you won't really need to do anything other than shocks, springs, and possibly a little more bump stop (not much though) for 31s.

The only real effect will be from the 31s (larger tires is almost always a need for a re-gear in most cases) and the need to re-gear.

 

[AndyG]

Makes perfect sense and is the exact reason that I want to regear. Of course, being a newbie when it comes to Jeeps and car modification/changes in general - I wanted to get the opinion and advice of people that have done it before. I’ve read a lot of other forums where people say it’s a waste of money, but I care about my Jeeps performance and want to do things the right way.

Having said that, if I end up changing my springs along with my shocks.. would a 1 inch suspension lift make sense? I read @Chris guide to lifts and I think he said for one inch lift you only need springs/shocks/stoppers? Of course, I would still be keeping the 31s and 4.10 regear but I figured maybe this would give the tires a little more space. Also, does a lift like this have any effect on overall car performance? I assume I does at least a little..

Most of the time the consequences from lifts are in the handling department .... And if you will stay on here you'll see a lot of good posts/threads to help you there.

 

[CLE1998]

I’ll probably just stick with no lift then if that is the case. I’m gonna have the regear done in the next 3 weeks or so.. I’m really excited to see the difference with the slightly bigger tires and regear. If anything Jeep should look a lot nicer compared to the stock tires

 

[AndyG]

I’ll probably just stick with no lift then if that is the case. I’m gonna have the regear done in the next 3 weeks or so.. I’m really excited to see the difference with the slightly bigger tires and regear. If anything Jeep should look a lot nicer compared to the stock tires

Always... I run 33" tires ...(insert gorilla sounds).


Remember- reelect Chris for Administrator 2021.

 

[CLE1998]

Always... I run 33" tires ...(insert gorilla sounds).


Remember- reelect Chris for Administrator 2021.

will definitely do! I read a bunch of his guides including the one about soft tops - and they are very detailed and informative. I will also be changing out my old stock soft top with a new bestop soft top.

I will definitely take pictures of the transformation and post so you guys can see the difference

 

[AndyG]

will definitely do! I read a bunch of his guides including the one about soft tops - and they are very detailed and informative. I will also be changing out my old stock soft top with a new bestop soft top.

I will definitely take pictures of the transformation and post so you guys can see the difference

That's a very good choice of product...

Keep us posted we love to see pictures of what you've got going.

 

[BlueFl.Wrangler]

My jeep came with tires that were just a bit over 29"— and now I have 31's

 

[AndyG]

My jeep came with tires that were just a bit over 29"— and now I have 31's

31 in is a nice usable size.

 

[Alex01]

I’ll probably just stick with no lift then if that is the case. I’m gonna have the regear done in the next 3 weeks or so.. I’m really excited to see the difference with the slightly bigger tires and regear. If anything Jeep should look a lot nicer compared to the stock tires

You could always run a 1" body lift to give the tires a bit more room. That way you wouldn't mess with any of the suspension. But, it's not necessary given the driving you do.

 

[CLE1998]

I think I’ve decided to replace the springs as well with the H&R springs. The link is Here

Looks like these would give me an inch suspension lift if they are the correct ones? Does anyone have these, and if you do are they good?

also, I know Chris said in his post that I need a stopper if I choose these.. what exactly is a stopper, is that the part at the top of the spring? If anyone can steer me in the right direction with a link or product info for the correct stopper it would be greatly appreciated. Thanks again guys.

 

[Rob5589]

HR springs are good to go.

 

[Sancho]

Hi everyone,

First time poster and long tim reader of the forum. I will be doing some upgrading to my Jeep tj and wanted to get some advice from you guys on what route I should go.

my current Jeep is a 1998 Sahara 4.0L manual 5 spd. It’s currently 3.07 gears. My current tires are 225/75/15 with no lift. I’m looking to upgrade to 31 inch tires with no lift, but was thinking that I should regear as even with the current tires I feel that the Jeep can be a little sluggish, especially uphill.

from posts I’ve read it looks like a lot of people recommend regearing to 4.10 for my Jeep.. do you guys think this is the right way to go? Will I see a noticeable difference when I regea?

thank you in advance to everyone

I suggest to keep it 3.07 if it will stay on the road.

You will maximize the gas mileage.

 

[89grand]

I suggest to keep it 3.07 if it will stay on the road.

You will maximize the gas mileage.

Not likely. I actually gained about 10% in fuel mileage going from 3.07 to 4.10. Not that I cared, but it was a pleasant surprise.

Even if I didn't, a TJ sucks so bad in the full mileage department, that I'd rather have a funner vehicle to drive with more power, even if gas mileage was less, but it will most likely actually improve. It's not good with 3.07's anyway.

 

[Alex01]

Not likely. I actually gained about 10% in fuel mileage going from 3.07 to 4.10. Not that I cared, but it was a pleasant surprise.

Even if I didn't, a TJ sucks so bad in the full mileage department, that I'd rather have a funner vehicle to drive with more power, even if gas mileage was less, but it will most likely actually improve. It's not good with 3.07's anyway.

Agreed.

I went from 14mpg with 3.07 and 33's to 13mpg with 35s and 4.88.

Mileage definitely sucks. But atleast it's consistent.

 

[CLE1998]

I suggest to keep it 3.07 if it will stay on the road.

You will maximize the gas mileage.

I'm not too worried about gas mileage. Even if that is the case, this is not a daily driver. It's more of a weekend and summer car. We keep it garaged in the winter here in Northeast Ohio to preserve it as much as possible.

Plus - gas prices aren't too bad right now

 

[CLE1998]

Also - I assume I have the Dana 30 front and Dana 35 back for my 3.07.. is this right?

When I regear to 4.10.. what will be my new setup. Dana 30/Dana 44?

The shop I spoke to said they use the 'Yukon' brand when regearing. Everywhere I search online I'm not seeing Yukon part options for the 98 tj with 4.10/4.11 gears.. am I missing something?

 

[Fouledplugs]

Also - I assume I have the Dana 30 front and Dana 35 back for my 3.07.. is this right?

When I regear to 4.10.. what will be my new setup. Dana 30/Dana 44?

The shop I spoke to said they use the 'Yukon' brand when regearing. Everywhere I search online I'm not seeing Yukon part options for the 98 tj with 4.10/4.11 gears.. am I missing something?

Yukon makes parts for you axles. They will work.

Post re-gear, it will still be a Dana 30 front and Dana 35 rear.
https://wranglertjforum.com/threads...d-what-the-difference-is-with-each-axle.9060/
You can type your VIN into a website and get a parts list of what you Jeep came with. It will include the axle identification.
https://wranglertjforum.com/threads/jeep-build-sheet-lookup.219/page-2

 

[HuskerJeep]

I think I’ve decided to replace the springs as well with the H&R springs. The link is Here

Looks like these would give me an inch suspension lift if they are the correct ones? Does anyone have these, and if you do are they good?

also, I know Chris said in his post that I need a stopper if I choose these.. what exactly is a stopper, is that the part at the top of the spring? If anyone can steer me in the right direction with a link or product info for the correct stopper it would be greatly appreciated. Thanks again guys.

I'm running 31" General Grabber ATX tires with the H&R 1" springs and the Rancho 5000's. I actually got 1.5" of lift out of the H&R's, which I like. Rides great, no complaints.