2005 LJ engine upgrade

Robert Bauer said:
Ok. I suppose they’re a better made set?


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Many would argue this. They are a better brand in general. Revolution is the company who bought out Superior. They are the only company I know of who still makes axle shafts that are manufactured in the USA. While the gears are manufactured in Korea, I have heard from many (including @Jerry Bransford) that they are manufactured to a much higher standard than other brands.

Absolutely get 5.13 gears. The Dana 30 unfortunately limits you on going any deeper, so 5.13 would be the obvious choice, and the deepest you can go. It’s going to make a huge difference, trust me.

I re-geared from 4.10 gears to 5.38 on my Rubicon (with the 42RLE auto transmission and 35s) and the difference is outstanding. My Jeep is totally transformed and actually has usable power for once!
 
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Chris said:
Many would argue this. They are a better brand in general. Revolution is the company who bought out Superior. They are the only company I know of who still makes axle shafts that are manufactured in the USA. While the gears are manufactured in Korea, I have heard from many (including @Jerry Bransford) that they are manufactured to a much higher standard than other brands.

Absolutely get 5.13 gears. The Dana 30 unfortunately limits you on going any deeper, so 5.13 would be the obvious choice, and the deepest you can go. It’s going to make a huge difference, trust me.

I re-geared from 4.10 gears to 5.38 on my Rubicon (with the 42RLE auto transmission and 35s) and the difference is outstanding. My Jeep is totally transformed and actually has usable power for once!
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I just checked out the website and they might be in the budget soon!


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There is probably better, but I've run g2s on both jks for thouands of miles with no issues.
 
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5.13 and 35s will put you about 10% over geared from a stock rubi. This is an excellent place to be, more would be better but unless you are also swapping in a front Dana 44 its all you can get.

G2 used to make a good product (I have em in my axles with no issues) however over the last year or so I've seen a lot of people who got them have failures. These gears are being installed by well known (locally) installers with no history of bad jobs so I'd tend to blame the gears. Revolution seems to be the go to for people on this forum, and I haven't heard any complaints. Yukon is also always an option if a bit spendy.

—
There must have been a time
when we could have said no.
 
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Robert Bauer said:
Since I can’t go to 5.13 gears with what I have I’ll probably go to 4.88. The set you posted looks good. I’ll have to wait a bit to do it since all the summer fun has taken its toll on my bank account. Especially since I bought a boat. But the engine swap might still happen.


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A boat...the one thing that will require more $$ than the TJ.
 
I have a 2005 LJ automatic that had 140K miles on it when I bought it. I regeared to 4.88 and it is a solid vehicle with a useful overdrive. I roll 33 inch tires though and not 35s. On 35s I'd think 5.13 gears would be right.
 
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No engine cures improper gearing .

There was an episode of myth busters i think where an inline 6 demolished bigger engines -because of torque.

The 4.0 will do fine , but if large tires were added and it wasn't regeared , it won't do well without a boat in tow , much less with one .

It will feel like you gained 50 h.p.

The 4.0 is great , but correct gearing is key .

It's not the engine , it's the oversized tires that create this .
 
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AndyG said:
No engine cures improper gearing .

There was an episode of myth busters i think where an inline 6 demolished bigger engines -because of torque.

The 4.0 will do fine , but if large tires were added and it wasn't regeared , it won't do well without a boat in tow , much less with one .

It will feel like you gained 50 h.p.

The 4.0 is great , but correct gearing is key .

It's not the engine , it's the oversized tires that create this .
Click to expand...

Yeah I know I definitely have to regear. But a bigger engine is always fun too. [emoji1]


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Robert- I feel your pain with the same exact setup but only 31s.
Even with 31s and 3:73 ratios it is a dog pulling a 24' toon. Or cruising in the mountains loaded with backpacking gear, tools, and two riders. But my hole in the water only cost $2000.
Regear-- that is what I'm going to do
 
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