LoneWolf

My understanding from this and other posts I've read indicate that the heavier tire and lower gearing provide more leverage to potentially break the axles. I suppose that's why the sleeves and gussets are so popular!

Sigh ... Just Empty Every Pocket -- and keep 'em empty.

rsbmg

Well there are a lot of pieces to the puzzle here as to what breaks and why and what causes what, that is why I was looking for a little clarification on the last part as to what exaxtly he was refering to breaking and why it does or does not break.

planman

1-Yes. Lower gears (higher numerical values) increase performance on and off road. On road the performance is higher because higher engine rpms=more horsepower and torque. Off road the performance is higher because the crawl ratio is improved and the ability to finesse through obstacles is improved.

2-Lower gears result in a smaller pinion and ring teeth, but the JK pinion is so much larger to start with than TJ axles have, and the high pinion front axle design of the JK axles is so much stronger to start with that the incremental loss of strength has not been enough to result in a high frequency of failures. Basically, if you do something so shocking and blunt to your drivetrain that it would blow 4.88s, it would blow 4.56s as well. A properly installed set of 5.13s survive more than most front and rear chromoly axle shafts. Certainly this is the case with up to 35s on JK Dana 30s and up to 37s on JK Dana 44s.

3-I'm saying that failures of properly installed JK gears are extremely rare for up to 35s on Dana 30s and up to 37s on Dana 44s.

rsbmg

Thanks! You know how sometimes you read something and it can be taken a couple different ways this all makes perfect sense.

GetLost

X2 to thanks planman-

atc22

I did 4.56.....no regrets at all. 35s daily driver spend some time on highways. Perfect gears for me. World of difference from stock.

TreyJK

What's the usual price difference between 4.56 and 4.88? I saw someone post that 4.56 was actually more expensive for them?

planman

If you have a non-Rubi, 4.56s cost $110 more: http://northridge4x4.com/shop/jk-non...-overhaul-kits

If you have a Rubi, 4.56s cost $150 more: http://northridge4x4.com/shop/jk-rub...-overhaul-kits

kdubflint

Sorry to dredge up this old thread, but I was lookin at going to 35's and was wondering why the 4.56 were so much more?

planman

They didn't make any sense for most all 07-11 JKs. So, not as many are made. With the increased demand from 12+ JK owners, they might come down in the future.