terrain

Recently purchased a 2010 Jeep Wrangler Sport with 3.21 gear ratio. Added 33x12.5 tires and lost most of the power in 6th gear. When I asked Dealer about changing the gears, they told me the only other gear they had was the 4.10 that comes standard on the Rubicon and that gear would not be compatible with my Dand 30 front end. There is an aftermarket company ( Alloy USA ) that does make a 4.10 that would be compatible with the Dana 30 but I am told by Jeep if I have that gear installed in would void the warranty on my powertrain. Now here is the rub, If you go to Jeep.com and click on Build Your Own, you can click on a tow package that will give you the 3.73 gear ratio. When I asked about buying the 3.73, I was told that it is not available through the Jeep National Parts Dept. Does anyone have any ideas on how I might get my hands on a set of these gears. If I could the Dealer would install them and I would keep my warranty in tact because they are a Jeep part.

nthinuf

Get the warranty in writing!!!! And be aware that it will be through that particular dealership only!! Unfortunately, adding any part that did not come with your jeep from the factory can void that part of the warranty, and any other dealership can and will tell you to go pound sand...

For the 3.73's, check the for sale section, or craigslist or ebay or where ever. Lots of people are getting rid of them when they upgrade. You can find them for cheap. You will also need a new carrier for the front axle. And install/overhaul kits.

However, I would suggest that you plug some numbers into the chart in the drivetrain FAQ- stickied to the top of this modified area. If you are paying $1000-$1500 for a gear swap, you would be better off moving up to 4.88's. And then you could move up to 35's. (just an opinion, of course... )

river2c

The 4.10 gear ratios were an option for the X and Sahara (Dana 30 front) in 2007. They are compatible with your Dana 30 front and you can order them through Mopar. You will need a new front carrier however. Not sure about the warranty issues.

terrain

NTHINUF: Thanks. I hear you about the warranty. Will look in the for sale sectionand also check Craigs List and Ebay. Just installed 33x12.5 tires so I think I will stick with the 3.73's if I can get them. Again thanks!

terrain

River2c: Are you sure that the 2010 Dana 30 will be compatible with the 4.10 offered in 2007. The Dealer is telling me they are not!

river2c

Same Dana 30 axle housing for 2007 up. The 3.21 gears use a different front carrier than the 4.10s. The carrier will run about $70. The 4.10s will fit your Dana 30 if you decide to go this route. If you ever plan on going with bigger tires than 33s, I would consider the 4.88s. You only want to regear once. Also, if you are looking at adding lockers, its more cost effective to do it at the same time as the gears.