JK Sport vs Rubicon (Used in Australia)

[bradsm87]

Hi guys,

I know Sport vs Rubicon has been done to death when they were near-new and when the AUD was better and the price difference between Sport and Rubicon was greater. Back then, the choice was pretty clear if wanting to run 35's or higher - get the Sport and modify it to be better than a Rubicon for same price. Now it costs a fair bit more for aftermarket gear due to the AUD and the earlier models of both are now cheaper and somewhat closer together in price.

In the end I want 4.88:1 gears, LSDs front and rear at minimum (Don't specifically need lockers as I think a combo of a torsen LSD like an Eaton Detroit Truetrac with the factory ESP system would work really well) and a Dana 44 front axle with housing strength mods. I'll be running 17x8.5 alloys with 285/75R17 (34") tyres. It seems there are two options:

2007-2008 Rubicon
- Nitro front axle sleeves
- DIY front axle housing trusses
- 4.88:1 gears front and rear
- "C" gussets

2007-2008 Sport
ALL of the above PLUS:
- Complete JK Dana 44 front axle (VERY expensive to both purchase and ship)
- Eaton Detroit TrueTrac LSD for rear (I like the idea of a full-time LSD in the rear and the ESP will pick up a lifted wheel quickly and the LSD will respond much better to this than a factory open centre)

I think the additional mods required to get the Sport up to scratch eat up the price difference between it and an equivalent Rubicon. A heavily modded Sport would have worse resale than a lightly modded Rubicon. This brings me to the conclusion that buying a Rubicon is better value.

Please do share your thoughts on the matter!

[Will239]

4.88 would be too low for 35"s. I run 35"s on a rubicon with factory 4.11.

I went through the same dilemma and if running 35"s the rubicon makes more sense. If you want to run bigger a sport may be better so you can put in even stronger diffs and lower gearing.

Don't forget the other advantages in a rubicon also like its higher spline axles and lower geared transfer case

[wranglertj]

I don't agree with your first statement but the mods you are specifying it doesn't make sense to have the Rubi as you are basically stripping what it is to have a Rubi so go a sport as cheaper

[bradsm87]

Originally Posted by wranglertj

I don't agree with your first statement but the mods you are specifying it doesn't make sense to have the Rubi as you are basically stripping what it is to have a Rubi so go a sport as cheaper

Why would I be stripping what it is to have a Rubi? I'd still use the lockers and Dana 44 front axle. The 4.1 gears? Yes, but at least I don't have to buy a complete Dana 44 front axle assembly as I would with a sport which is $3.5k shipped at minimum.

[bradsm87]

Originally Posted by Will239

4.88 would be too low for 35"s. I run 35"s on a rubicon with factory 4.11.

I went through the same dilemma and if running 35"s the rubicon makes more sense. If you want to run bigger a sport may be better so you can put in even stronger diffs and lower gearing.

Don't forget the other advantages in a rubicon also like its higher spline axles and lower geared transfer case

Good to know that I might be OK with 4.1:1 diffs. That would save a lot of stuffing around.

I'm not sure that the 4:1 transfer case would be a plus for me. I certainly won't be crawling up ridiculously steep rocks etc that require such a high reduction. I wouldn't see myself using low range 1st in a Rubi in any other scenario. I'd be just as happy with the Sport's 2.72:1.

[chris0375]

Or you buy a diesel with 4.1 ratios and avoid the 3.8. Changing ratios is very expensive and you are unlikely to get it back in resale. That would more than pay for a dose of tlc on a diesel and maybe even a tune too.

I am sceptical of the benefits of an lsd and the factory traction control. Not saying that you are wrong but I would be doing some more research. Personally I think unless they are significantly cheaper than proper lockers they aren't worth it.

[bradsm87]

Originally Posted by chris0375

Or you buy a diesel with 4.1 ratios and avoid the 3.8. Changing ratios is very expensive and you are unlikely to get it back in resale. That would more than pay for a dose of tlc on a diesel and maybe even a tune too.

I am sceptical of the benefits of an lsd and the factory traction control. Not saying that you are wrong but I would be doing some more research. Personally I think unless they are significantly cheaper than proper lockers they aren't worth it.

I'm not a big diesel fan myself but certainly not knocking them. I'm thinking engine conversion in the very long term anyway so the cheaper petrol model is more suited for me.

They are half the price of lockers. People say factory ESC works quite well, even with open centres. A torsen LSD changes the torque split from 50/50 to up to 20/80 when needed so it would require 1/5 **edit: 2/5 ** the amount of braking on the spinning wheel for the other wheel to hook in compared to an open centre. I upgraded the open centre to a helical LSD in my road car and it made a huge difference. Love it!