Jeep Wrangler Forum banner

1 - 20 of 196 Posts

·
Registered
Joined
·
39 Posts
Discussion Starter #1
I have a friend who purchased a Rock Krawler X Factor lift. We noticed the following issues:

1. The X factor is supposed to extend the wheel base by 1 inch as I understand it. When it setup like this his rear wheel hits the body pinch seam in the rear wheel well when under compression.

2. When the front suspension is fully flexed the bump stop misses the white bump stop knob on the frame on the compression side. The white bump stop ends up sliding off towards the rear and ends up between the lower bump stop and the coil spring.

Seems to me this may be why Rock Krawler suspensions can sometimes flip the sway bar links forward on Rubicons and bend them. I have seen this online and a friend saw it happen in person.

Seems to me that whatever geometry changes they incorporated into their lift is causing misalignment of the bump stops and interference with the pinch seams under full compression. The front bump stop issue potentially allowing too much flex and bending the front sway bar links on Rubicons.

In their instructions they recommend you get disconnects even on Rubicons. That seems crazy to me. Why would I pay all that extra money for a push button sway bar disconnect just to disable it and have to dick around with rusty stubborn sway bar links out in the cold?
 

·
Super Moderator
Joined
·
53,758 Posts
Let me guess.
The arms were set using the instructed lengths?
Did he get a alignment.
Does he know what caster angle is ?
How about rear pinion angle ?

Yes, the RK x-factor moves the front axle .5 forward and rear axle 1+ inches. There is a note in the instructions that says. The numbers are only a baseline and A professional alignment is recommended.

I see this way too many times. If not setup correctly, it can cause issues.
 

·
Super Moderator
Joined
·
53,758 Posts
Disconnecting the swaybar in high flex situations is recommended. Edit: when did he buy the lift kit?

Edit x2 (added for reference)
RK's updated component lengths.


Wow, sorry we do not provide incorrect information. There is a lot of small tolerences that would add into something like that. Every operation on the arm has a tolerance so if we mis-speak of mis-type something, we really don't want to be crucified for it by people on the forum or one of our Engineers for being wrong.

Here is our basic arm setup dimensions and they can be adjusted from here...

Front Track Bar (RK02024)
1.5” lift – 32 1/2”
2.5” lift – 32 9/16”
3.5” lift – 32 5/8”
4.5” 2 door lift (w/ bracket) – 32 19/32”
5.5” 4 door lift (w/ bracket) – 32 5/8”

Rear Track Bar (RK02026)
1.5” lift (w/bracket) – 39 11/16”
2.5” lift (w/ bracket) – 39 3/4
3.5” lift (w/bracket) – 39 3/4”
4.5” lift (w/bracket) – 39 7/8”
5.5” lift (w/bracket) – 40”

Front Lower Control Arms (RK02015)
1.5” lift heights – 23 1/16”
2.5” lift heights – 23 1/8”
3.5” lift heights – 23 1/8”

Front Upper Control Arms (RK02020)
1.5” lift heights – 19 1/4”
2.5” lift heights – 19 5/16”
3.5” lift heights – 19 3/8”

Rear Lower Control Arms (RK02064) [FLEX REAR LOWER CONTROL ARMS]
*Works with Factory Rear Upper Control Arms or our RK04852 Arms
1.5” lift heights – 19 3/4”
2.5” 2 door lift heights – 19 7/8”
2.5” 4 door lift heights – 20 1/8”
3.5” 2 door lift heights – 19 3/4”
3.5” 4 door lift heights – 20”

Rear Upper Control Arms (RK04852) [FLEX REAR UPPER CONTROL ARMS]
*Works with Factory Lower Control Arm or our RK02064 Arms
1.5” lift heights – 17 1/2”
2.5” 2 door lift heights – 17 5/8”
2.5” 4 door lift heights – 17 9/16”
3.5” 4 door lift heights – 17 5/8”

X-Factor Rear Lower Control Arms (RK02022)
*Works with our RK02028
1.5” 2 door lift heights – 20 1/2”
1.5” 4 door lift heights – 20 5/8”
2.5” 2 door lift heights – 20 9/16”
2.5” 4 door lift heights – 20 11/16”
3.5” 2 door lift heights – 20 5/8”
3.5” 4 door lift heights – 21”

X-Factor Rear Upper Control Arms (RK02028)
*Works with our RK02022
1.5” 2 door lift heights – 18 5/16”
1.5” 4 door lift heights – 18”
2.5” 2 door lift heights – 18 3/8”
2.5” 4 door lift heights – 18 1/16”
3.5” 2 door lift heights –18 7/8”
3.5” 4 door lift heights – 18 9/16”


Note: All Control Arms and Track Bars come pre-assembled, but they require final adjustment. These measurements are taken from the center of one bolt hole to center of the other bolt hole.

The rear upper control arms and track bars are double adjustable where as the front uppers and lower arms are single adjustable.

An estimate on Adjustability would be as follows;

Track Bars and Mid Arm Rear Uppers +/- 5/8" or 1.25"
Mid Arm Front Uppers +/- .313 or 5/8"
Mid Arm Lowers +/- .375 or 3/4"

By SAE standards you can actually adjust them even more, but we just don't like to have too much shank hanging out there as that becomes a point of weakness regardless of shank size.

Hope that helps and give you some ideas.

RK
 

·
Super Moderator
Joined
·
8,178 Posts
Also, what size tires does he have? If 35s, he definitely has the axle too far back (arms too long) and should be able clear that back seam once it gets readjusted. If 37s, you may need to pound/hammer/roll that seam back in the rear of rear wheel well BUT the tire should only be getting even close to that seam at max full extreme stuff like on a RTI ramp or forklift - otherwise, it is a symptom of again having the axle too far back. With 37s, mine just barely contacted the pointy bottom edge of the seam on the forklift - I prefer more than a hair between a $400+ tire and anything pointy so we just pounded it back with a BFH.

I never had any issues with the front so no help there. After a few stabs, I think I finally have all my back end alignment issues resolved (fingers crossed!).

As far as the disconnects on Rubicon, they can overextend under extreme flex on ANY lift, not just Rock Krawler. A friend with Teraflex lift overextended recently on his. When I run easy stuff, I use the push button. When I run big boulders, I use the RK disconnects.You dont disable the push button ones?

And what kjeeper said ^^^^^^.
 

·
Premium Member
Joined
·
554 Posts
I might not be picturing this correctly but if I am im wondering how the front axle can be so far forward the bump stop slides to the rear but the springs don't contact the discos? haha I just pictured a Whataburger roof for a bumpstop cause that would make sense.

Every jeep is different I know, but on mine which I am currently installing I had to dial back from baseline measurements just to keep things from touching at ride height.

On the rear I haven't had mine to full stuff but unless your at the limit of acceptable threads showing, shouldn't you be able to adjust that? Once the arms are past horizontal they'll start pulling in but looking at mine on 35's I should have plenty of room.

EDIT: just realized im thinking of the wrong seam. I thought you were saying the pinch welds in front of the tire, my bad

Just curious but what shocks is he running? keep us in the loop all these threads are helping me install mine correctly.:popcorn:
 

·
Super Moderator
Joined
·
53,758 Posts

·
Registered
Joined
·
39 Posts
Discussion Starter #8
My friend is running 37's and has had it professionally aligned.

With all due respect I have to disagree with the statement that "ANY" lift under extreme flex can flip and bend the front sway bar links.

There are Rigs out there with greater flex than Rock Krawler and they don't bend the front sway bar links on a Rubi.

The shocks control the amount of total extension and the bump stops control the amount of compression. The length of the length of the sway bar links factors in.

Now if your missing the front bump stop all together under compression that would cause the suspension to over extend and bend the front sway bar links.

The Designer has complete control over how much flex the Jeep will have and can prevent bending the front sway bar links if he really wants to.

I was just wondering if others out there have tested flexing their rig with a fork lift or large bolder and found this issue.
 

·
Super Moderator
Joined
·
8,178 Posts
Any lift can with any links end over the actual sway bar where it disconnects in middle on Rubicon when you use the button. I was not talking sway bar links.
 

·
Super Moderator
Joined
·
53,758 Posts

·
Registered
Joined
·
970 Posts
It seems to my read that the rear CA's are too short and the front CA's are too long. Any chance they were somehow reversed?

Either way, all the talk of alignment, castor, pinion angle etc is secondary to the location of the axles. The actual length of the CA's should be posted for a better chance of help...Pics might be good also.
 

·
Premium Member
Joined
·
554 Posts
It seems to my read that the rear CA's are too short and the front CA's are too long. Any chance they were somehow reversed?

Either way, all the talk of alignment, castor, pinion angle etc is secondary to the location of the axles. The actual length of the CA's should be posted for a better chance of help...Pics might be good also.
I was thinking the same thing on the CA being reversed, took me a few times looking at it to not get them mixed up.
 

·
Premium Member
Joined
·
554 Posts
I believe the longest CA is the front lower, that's what confused me. I figured the biggest would be in the back. Or maybe I put them on wrong......shit.....
 

·
Registered
Joined
·
39 Posts
Discussion Starter #18
Love the specks!

He's pretty sure he got them right because the boxes were labeled and he did one set at a time. If they weren't boxed right he's boned. You can't argue when you can check the lengths!

Thanks Dude...Great feedback!
 

·
Registered
Joined
·
492 Posts
I just installed a 3.5" RK X Factor on my 2014 JKUR last Saturday. It went well. Having the alignment done tomorrow. She rides nice and drives straight....the steering is firm (not flighty). I am hoping everything checks out on the alignment tomorrow. The rear pinion angle looks good....need to do an official measurement this week. My only issue is a slight clunk in the passenger front on big bumps...I have not been able to figure that one out. I re-torqued all the control arms yesterday (after 75 miles of driving). Any ideas?
 
1 - 20 of 196 Posts
Top