I have had a 93' Grand Cherokee for the past 5 years. I put a lift, locker, and some 31's on it. Nothing big, but it did me well for a couple trips to Moab and plenty of Nevada desert trips. Its becoming more of a hassle to keep up and I really want to get a JK 4-door Rubicon edition.

My experience has only been with the buying the Grand Cherokee and fixing it up myself. I want a newer JK for the better wheeling capacity as well as the 4-door (for the fam). I want to lift the JK and put 34"-35" on it. I just saw the post on Full Traction's Rubicon and I think thats what I am looking for.

But I have some questions, bare with me as some might be dumb but this is a big purchase for me and I need to make sure I am doing it right.

Does a lift void any warranties?
Do dealers offer services to lift the vehicle, or should I take it to another shop?
With 34"-35" how much of the mpg or power will change? (with my 5.2L ZJ it got better gas mileage, as it had the power to turn the bigger wheels).
Last time I lifted the truck with the bigger tires, I didn't get the odometer changed so the miles where all off, do i need to ask for this to be done when getting the bigger tires/lift?


I am in Las Vegas and do not know of any really good Jeep shops, if somebody knows of one that can do JK's please let me know. I would even be interested in knowing if there are shops in the western states that would do a really good job at a decent price. I want a shop that really knows JK's not just I can do it.

 

Hi kaibab, welcome to JK-Forum and the only dumb question here is the one that isn't asked

"The installation of aftermarket components on your vehicle does not directly void your vehicle's warranty in the United States. However, your vehicle's warranty does not cover problems with aftermarket components, and your vehicle's warranty does not cover problems directly caused by aftermarket components. In the event that a problem with your vehicle is caused by an aftermarket component, your dealer must provide sufficient evidence of this to legally deny warranty coverage.

For instance, if you were to install a suspension lift on your vehicle, the rest of the original equipment systems on your vehicle would remain covered under warranty unless the aftermarket suspension was proven to be the cause of a problem. Your aftermarket suspension would most likely be covered under its own manufacturer's warranty.

These rules are set by the Magnuson-Moss Act, the federal law governing warranties on consumer products. Follow the links on the bottom of the page for more information." - OK4WD.com

No dealer that I know of offers this kind of service. Most will refer you to a local shop that they use.

If you get a Rubicon, it will have 4.10 gears and although you will experience power loss, it should be tollerable up to 35's so long as you're driving a 6-speed. However, if you're really concerned about power loss and MPG, then I would recommend you regear to 4.56 (for best MPG) and 4.88 for best power performance.

All you need to do is change out the speedometer gear to one with the correct tooth count. The gear should only be about $20 from your dealer and it should only take 2 minutes to swap out.

In all honesty, who or what shop could possible know JK's at all at this point and time. Plus, if you have experience with a ZJ, then I would bet working on a JK would be easier. Need I say, I would recommend doing your own install or find a local club to help you out. Heck, if you'd be willing to drive out to SoCal, I would help you out for free

 

Thanks for the detailed information. I will go the local Jeep club route first and see if I can get some local help, then I might take you up on a trip to SoCal.

I plan to get the automatic for various reasons, so I am interesting hearing more about the gear ratio issue with the bigger tires.

I figured 4.10 was pretty good but I haven't had a truck with 35" tires before.

I assume the 4.56 and 4.88 gears are standard Dana 44 swaps. The JK Rubicon has Dana 44's front and back are they non-standard in any way?

After I get my truck, I might just wait a while before doing the lift and bigger tires to see what the aftermarket comes out with.

 

4.10's work well with 33's but with 35's, you will experience a noticable amount of power loss especially when climbing hills. It's not so bad with a stick as you can determine when to shift but in an auto, all the shift points can feel quite off. I'm not 100% sure but I would think you could have your computer set to address this problem and help things out a bit. Otherwise, both 4.56 and 4.88's are standard gears but I'm not sure if anything has changed in the new Dana 44's that would require special ring & pinions. I know that was the case with the TJ Rubicons who's gear sets were thicker and typically ran about $50 more than standard gears.

By the way, where abouts in Vegas are you? I have in-laws that live in Henderson.

 

I grew up in Henderson close to Railroad pass out towards Boulder City. But I live across the valley by Red Rock now because of work.

Makes sense.

What other issues do i have to think about taking a JK Rubicon 4 Door up to 3"-4" lift and 34"-35" tires?

 

No kidding - there's some fun wheeling up in the Red Rock area

Other issues you might want to consider with 35's (if you plan on wheeling your Jeep hard) is upgrading to chromoly axle shafts and a new drive shaft with U-Joints. Also, with the exception of Interco, there are few manufacturers that make a 34" tire and I would probably recommend you stick with something a bit more standard. There's nothing like being out in the middle of nowhere with 2 flats and no replacement to be found anywhere. :eek:

 

Yeah, Red Rock and Logandale Trails (1 1/2 hour away) are ok trails, Moab is still better, hehe.

Looks like its alot to bite off right in the begining, I'll probably stick with stock and work up to the big stuff. My Jeep Grand Cherokee with 31's and a back locker did Golden Spike and Widow Maker without any problems at Moab. Its a different kind of wheeling of course (when comparing it with a TJ) but it works for me.