I'm starting to second guess myself. I ordered a 2012 JKU Rubicon, and in preperation of its arrival I purchased the RK 2.5 max travel kit from Northridge4x4. I'm going to be running 35's (BFG km2's). I wanted to maintain optimal on road manners and not have to worry about needing to replace the driveshaft(s), so I went with the 2.5 max travel. I don't do rock krawling per-say, but I do need it to be able to flex without rubbing issues for the type of things I get into, and I don't want to be limited and not be able to do some rock krawling in the future if it seems a new hobby to get into(I live in Colorado). Just switching out the springs to the larger 3.5 lift will screw up the on road performance wont it, without getting additional components to correct the geometry, or is it really not necessary. Does going to the 3.5 lift require new drive shafts, or at least a new front ds? How many of you are running the 3.5 flex without new driveshafts, and has it been okay, or are you needing/wanting to upgrade to a more complete system? Or is all this just unneccessory worry/stress, and I should just stay with the 2.5?

 

I can't speak for 2012 but in my 2008 with the 3.5 RK X suspension I did need to replace my front DS. It was contacting the transmission pan and skid plate.

You'll love the RK products. I would say go with the 2.5 for now. Sounds like it will do you well.

 

I have a 12 I just bought a rk 5.5" mid arm and swapped the coils for 3.5". They say you need a new front ds so idk then exhaust spacers from teraflex or the AFe y pipe to fix the problem with it hitting the exhaust. But I guess that's why you get a smaller diameter ds. And think about flat fenders it might help not rub.

 

I'm running a 2.5" TeraFlex coil lift on an '08 2 dr 6 sp. and after my first wheeling excursion at Rausch Creek I noticed the notorious grease splatter from the front DS boot. I have a new Coast 1310 on the way.
My point being that even at 2.5" if you're going to be at full flex the front DS may be an issue. I am sure I could probably run it this way for a while but I'd rather not take the chance of it failing when I need it.

 

Won't make much difference.

 

I do have the exhaust spacers, so should be good there. The 2.5 hasn't been installed yet, so switching out now would only cost me shipping and the difference in the larger springs, at least I think that's all it would be. I hadn't heard a new driveshaft may be needed with the 2.5. If thats a common thing then I guess thats another reason to consider the 3.5, gotta get a new ds either way you go. What about on road with the less complete, for the lift height, system? Not wanting to upgrade to the full 3.5 max travel package due to the cost for the time being.