Should I be worried about this gearing?

[scotmotzny]

So, I'm new to all of this and looking for an '04-'06 LJ. I found one with 33" tires, 3" suspension lift with the inline 6 cylinder manual transmission. The dealer says that it is geared at 3.73.

This is the cars.com listing.
https://www.cars.com/vehicledetail/detail/747471439/overview/#calculator-top

Should I be worried about that gearing? Sounds like it should have a 4.56 gearing according to your post. I'm not worried about revving it higher on the highway as long as I have proper performance on the trails. Not planning on rocking this thing, but would like to be able to hit some dirt trails, cross a creek, and generally not get stuck in the backwoods.

Thanks!

Scot

 

[Badmfbri]

So, I'm new to all of this and looking for an '04-'06 LJ. I found one with 33" tires, 3" suspension lift with the inline 6 cylinder manual transmission. The dealer says that it is geared at 3.73.

This is the cars.com listing.
https://www.cars.com/vehicledetail/detail/747471439/overview/#calculator-top

Should I be worried about that gearing? Sounds like it should have a 4.56 gearing according to your post. I'm not worried about revving it higher on the highway as long as I have proper performance on the trails. Not planning on rocking this thing, but would like to be able to hit some dirt trails, cross a creek, and generally not get stuck in the backwoods.

Thanks!

Scot

I've got an 05 LJ and for the past 2.5 years I've been riding 33" tires with the OEM 3.73 gears. It does just fine on the road and on the trail. You should be OK, but for performance you might want to gear up at some point. I'm finally getting my 4.56s installed in December.

https://www.quadratec.com/jeep_knowledgebase/article-26.htm

 

[jjvw]

.... I'm not worried about revving it higher on the highway as long as I have proper performance on the trails. Not planning on rocking this thing, but would like to be able to hit some dirt trails, cross a creek, and generally not get stuck in the backwoods.

Thanks!

Scot

Proper gearing on the road will only translate into more enjoyable gearing off road. Gear low.

 

[scotmotzny]

I've got an 05 LJ and for the past 2.5 years I've been riding 33" tires with the OEM 3.73 gears. It does just fine on the road and on the trail. You should be OK, but for performance you might want to gear up at some point. I'm finally getting my 4.56s installed in December.

https://www.quadratec.com/jeep_knowledgebase/article-26.htm

Thanks for the information and that Chart is very helpful! Have a Happy thanksgivng.

 

[jjvw]

Thanks for the information and that Chart is very helpful! Have a Happy thanksgivng.

You may want to read the entire thread. Don't pay attention to the chart or Bleepin' Jeep.

 

[Don A.]

Just to provide something useful out of this post, here are what I and many other forum members have determined to be the best ratios for Wranglers older than 2007 that have the 4.0L, 2.5L, or 2.4L engines.

4.0L engine

5-speed manual (AX15/NV3550)

31's - 4.10 (this is how the Rubicon came)
33's - 4.56
35's - 4.88
37's - 5.13 or 5.38 (personally I'd choose 5.38 which adds about 100 RPM to help for the larger 37" tires)

3-speed auto (32RH) used 1987-2002, deemed the TF999 in older 1987-1991 YJ Wranglers

31's - 3.73
33's - 4.10
35's - 4.56
37's - 4.88

4-speed auto (42RLE) used 2003-2006, actually used longer in the JK but I'm not including JK Wranglers.

31's - 4.56, even though the factory Rubicon used 4.10 unfortunately
33's - 4.88
35's - 5.38 (Rubicon's have to change carriers to support this deep of a gear ratio)
37's - forget about it unless you get axles that support 5.89.

6-speed manual NSG370
31's 3.73 more street, 4.10 more trail or mountainous/hilly highway
33's - 4.10 more street, 4.56 more trail or mountainous/hilly highway
35's - 4.56 more street, 4.88 more trail or mountainous/ hilly highway

2.5L & 2.4L engine

5-speed AX5/NV1500

31's - 4.56/4.88 (either is good, 4.88 really helps keep speed on the highway)
33's - 4.88
35's - 5.38 if you have the axle for it, otherwise 5.13

3-speed auto 30RH

31's - 4.10
33's - 4.56
35's - 4.88

4-speed auto 42RLE

31's - 4.88
33's - 5.13 or 5.38 if you can run them.
35's+ - wouldn't even consider it.

Thank you for all the good info. On the earlier post of the suggested ratios for each engine, the 2.4l with a 6 speed manual wasn't on there. If I could piggy-back on this thread and get some advise, I'd greatly appreciate it. I recently have been looking into regearing. I have a 2006 2.4l with a 6 speed manual trans. the PO installed a 2" BB and its rolling on 265/75r15 tires. I believe it has 3.73 gears. Right now I really like how it drives...hilly highways being the exception. I would like to run 33x10.5x15s. What are your thoughts on this combination? Thanks.

 

[Don A.]

Also, if 4.88 is best for 33s would they work with 31s too?

 

[jjvw]

Also, if 4.88 is best for 33s would they work with 31s too?

Look at grimmjeeper.com and see how the rpms change with different gear and tire combinations.

 

[Don A.]

Thanks @jjvw

 

[Rob5589]

2.4/6 spd: 31/32 4.88, 33 5.13

You want to be around 3000-3100 at 70 in 6th gear for best performance

 

[AndyG]

Regear ..you will be very happy

 

[makorider]

Interesting website, my 05 Rocky Mountain came lifted on 33s with a bunch of upgrades and I've been wondering whether its been regeared or not.

I'm turning 2500 rpm at 70.

But I don't know the transfer case or its ratio. Anyone know the tcase on an 05?

 

[jjvw]

Interesting website, my 05 Rocky Mountain came lifted on 33s with a bunch of upgrades and I've been wondering whether its been regeared or not.

I'm turning 2500 rpm at 70.

But I don't know the transfer case or its ratio. Anyone know the tcase on an 05?

The transfer case is a np231, but that won't play a role in the gearing because it will be in direct drive when on pavement.

What your care about is the transmission, which is either the 42rle automatic or the nsg370 manual

 

[makorider]

Yeah I've got the nsg370, forgot to mention that.

So I've been regeared according to the chart.

Whats a common gearing in the low 4s? Stock according to build sheet is 3.73

 

[jjvw]

Yeah I've got the nsg370, forgot to mention that.

So I've been regeared according to the chart.

Whats a common gearing in the low 4s? Stock according to build sheet is 3.73

4.56 with your transmission pushing 33s.

 

[makorider]

No, has to be less. Im right at 70 +/- an mph or so at 2500

Chart says 2730rpm at 70 w 4.56, 2233 w 3.73, so I'm somewhere in between

Is 4.10 a commonly available gearing? That would make sense

 

[jjvw]

The Grimmjeeper suggests that your axle gearing is 4.10, which was available from the factory on certain models. Or your axles have been regeared or swapped.

Your ideal gearing would be 4.56.

 

[makorider]

As I said, build sheet said 3.73 but 4.10 seemed to give me the numbers I have, didn't know if that was a common gearing.

Guess it is, and thats what it was regeared to.

Thanks

 

[jjvw]

If you want to confirm, do this...