If i were you I would skip the RCV's because in a d30 the r&p are already pretty much the weak link and then add (pretty much) un-breakable axles shafts... Not a good idea and a axle shaft is a lot easier and cheaper to replace then the R&P.

 

I would not waste the money on those shafts for a dana 30 either. Just trowing away good money on a product that is not designed for what you are doing with it. You can truss it, gusset it, sleeve it, lock it, gear it, add awesome shafts, and you still have a dana 30 with the small R&P, weak tubes, and shitty unit bearings. The actual important things on an axle.

 

I've been researching lifts for my 2015 jku 4dr for the last couple of months and this was by far the most informative forum. I was looking at big lifts big tires, thanks for the money saving tips! So if I got this right a good 2.5" lift with flat flares and 35" tires is more than I need for beach and trail riding ? Don't think I'll ever go rock crawling (would love to but wallet says NO). Would 33's be better than 35's? I have 6spd manual with 3.73 gears, Dana 44 in the rear,Dana 30 in the front. Also with the new traction controls on the jk do i need lockers?

 

35's will look better and allow for more traction when deflated over 33's however they might be a bit sluggish on the road but you should be fine. Lots of people run 35's and the 3.73 gearing.
My wife is from Jax and she just got back from visiting her family.
Good luck with the upgrades.

 

My 2012 JKU was noticeably sluggish when I went to 35's with the 3.73 and 6-speed manual. I was always whining at high RPMs and getting no oomph. Highways and hills were no fun. I'd recommend gearing up to 4.56 if you go with 35's, or just go up to 33 since you said you aren't going to wheel much.

 

Question...

I have a 2015 2 door sport with a 2 and a half inch puck lift in front and 2 in back... I have the lowest stock spring level that jeep makes. My question is, if I go to a higher spring level like 17/58 or 19/60 is that going to be too tall with the puck lift? I'm worried that I'll be above that 2 1/2" lift comfort level everyone talks about.

Will I feel a big difference going from my soft springs to the taller and stiffer springs? Is it worth the change?
Thanks!

 

Like common sense would tell you, you will gain some height and the ride will be more stiff. As far as how much you will actually gain is jeep dependent and personally I would say it would not be worth the trouble of swapping them.

 

It's a cheap upgrade. The difference between my soft, short springs and different longer stiffer springs seems like it would be pretty substantial. I already have the puck lift. So my real question from my original post would be, is the 2.5" sweet spot that everyone talks about measured from the short springs or the long springs that are about an inch taller. Considering we are talking about a stock weight jeep.

 

Coils are same length but use different coil rates so you don't gain any extra ability to droop farther then with the lower rate coils. They will however give you a rougher ride and off road will perform poorly off road. The only ride quality upgrade would be at high speed where you will be more stable in the corners but that may be offset by the additional roll height you get.

2.5" is not some magic number to be concerned about. Its all about how you set it up and how you drive it. You could just throw on some 4" coils and be fine without swapping anything else on the jeep. It would drive like shit and you would not take it off road, but you could get away with driving it on the road. You could run 2" of lift with longer travel shocks and rock stars and have issues with driveshafts and dropping coils. Think of the suspension and steering as a set of triangles that are all connected. You need to realize how they are connected and how changing one leg of the triangle (like coil length) creates changes to the entire system. Small changes create small problems to the system where big changes can totally screw up the entire system.

 

Thank you that's what I needed