Hey everyone,
I recently installed the 3.5 xfactor on my 2015 Rubicon. It's their short arm kit. I set all the measurements correctly for the control arms, if stretched the front a little bit which is fine and was supposed to set the rear back an inch but it's much more. Even with the coil wedges the springs still have quite a bow in them. We will have to cut the spring perches and re weld them which is no biggie, just some time. I'm just curious as to if anyone has had to cut away part of the rear quarter panel to make this kit work properly. It's stretched it about 2.5 to 3 inches. Even if I take the arms down to the shortest length I'm well into the pinch seam. If anyone can let me know their experience with this kit it would be greatly appreciated. I'm not sure if they changed something small on the 2015 models, I know I had to drill out the front swaybar to accept the end links. Who knows lol. On a side note I love the ride and the quality. Other than a high steer kit it was very complete and install was relatively painless.

 

What size tires. So if you compare them to the stock control arms the rears are 2-3" longer then the stick arms? I'm confused how you got a 2-3" stretch in rear unless you adjusted the arms wrong. There shouldn't be a lot of thread showing for the lowers and not too many for the uppers either.

 

I am no help on this one but I am interested to see what you find out.

 

I have the exact same lift with the same issues. I don't have any problems with the front springs Bowing at all, but the back is a whole different story. With 1" stretch in the back, the springs will bow excessively even with the proper castor and control arm measurements. This bow causes the rear end of my jeep to sag and bottom out more often than necessary due to the bowing of the rear springs. I haven't heard of anybody repositioning the upper spring perches to alleviate this issue. What a lot of people do to help reduce the bowing is to get new lower spring perches and weld them on at angle in which the spring sits more naturally. Personally, I just went with coilovers which completely eliminates this problem.

 

Depending on when you bought the kit, the rear arms were shortened 3/8 or so. I don't think the instructions reflect the changes. What does your pinion angle look like ?
You might want to call RK on the changes.

With That being said. The numbers should only be used as a starting point.
My RK arms are shortened but i would set them as short as possible. Once the lowers are set and bolted up, use a jack to hold the pinion -2° below the DS. Adjust uppers to match the mounts, no measuring required. Drop jack and measure pinion angle. If good torque all the bolts. Good luck

 

What did you set the lowers to?

The PDF shows
Rear lowers
2 door 21"
4 door 21 3/8

Rear uppers
2 door 19 3/8
4 door 18 5/16

 

You can cut about 1.5" off the rear pinch seam before running into the panel that seals the corner off from the fender well. I trimmed mine to squeeze in 37's.

 

I just bought it a few weeks back, not sure how long it was in stock though. Thanks for the tip, I wasn't super pumped on cutting up a jeep with a short arm kit lol.

 

I'm running 37x12.50x17 Mickey Thompson MTZ

 

I've been running the X factor for the last 2 years on my 4 door and my rear springs are bowed also. I haven't had any problems with them my jeep still drives and flexes fine on and off-road. RK said its normal for the rear springs to be like that with this kit, not sure if it's good or not but no problems yet for me.