Originally Posted by 269jeep
Why 4:56 over 4:11? Can I still use stock D30/D35's with 4:56? And yes I am asking around for a well referenced axle/driveline shop.
4.11 doesn't quite restore the power lost by the bigger & heavier 33" tire size. You can't simply regear to restore the stock engine rpms that worked for a smaller tire size since bigger tires require more engine power to turn... which means slightly higher RPMs than before. I installed 33" tires 15 years ago & against the advice of more experience Jeepers, I chose 4.11 instead of the 4.56 they recommended. The 4.11 gears initially felt great but within a few days I realized I had made a mistake of not going to 4.56... I was always having to downshift for even a very minor grade. No, 4.56 doesn't mean excessively high highway rpms... 4.56 is ideal for the highway with it also being ideal for offroading.
Not to mention the factory considers 4.11 (aka 4.10) ideal for 31" tires which is what it gears the Rubicon to for its factory 31" tires. 4.11 can't be ideal for both 31" and 33" right?
Finally, don't buy gears on your own with the intention of saving a few bucks and then paying a shop to install them. When you provide the gears, the shop will only warranty its labor & not the gears you provided. If something goes wrong, the shop will blame your gears & you'll be stuck. If the shop provides everything, their warranty will cover everything. And problems do arise from installig new R&P gears. The 4.88 gears I installed 10-12 years ago went bad 6 weeks after installing them from a bad setup by the installer. The shop I used apologized & took care of everything. They wouldn't have if I had provided the parts they used.
Hope that helps.