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Unread 07-23-2013, 02:04 PM   #1
dawgfan77
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JK handling issues above 55mph

We are now the proud owners of a 2012 JKU (my wife's actually), which came pretty decked out. I had my reservations the 1 st few times I drove it, but I've always wanted one and I guess that swayed my judgement, so when I finally convinced her to get one(I love my truck and cant afford both) I jumped at the chance. She found and fell in love with a freshly traded Sport with ~4000 miles on the clock, 6 spd manual, Hard top, a brand new lift kit(Rough Country), 20x35x12.50 Trail Grapplers on Hostage wheels, Bushwacker pocket flares, rails, and a few other things. I say I had reservations only because the idea of a lifted jeep on 35's isn't really what I consider a "family vehicle" for her and my 2 daughters, but damn is it cool! Anyway, it drives fine around town, but we took it to the beach this weekend and I got to really stretch its legs for the 1st time.... and it scared me! I can't use 6th gear.... unless going down hill(no biggie)! It will not hold speed. 5th will hold whatever speed you want, but on anything less than a straight, smooth, newly paved 2 lane road, 55mph is as fast as I felt comfortable driving. It has no DW, but it skates around as if you are driving in a 30mph gusting crosswind. I had the alignment checked the day before we left and was told it was less than 1/2 degree out of castor (or camber, which ever one is the forward/backward pitch, i forget) which I'm sure is due to the lift. All else was tight and still new, currantly ~6000 miles. I have a set of factoy 17" wheels with brand new 285-70-17 Destination MT's that I put on it for a day just to see the difference. It was noticably better and they rode better than the trail grapplers, but still not factory handling. I already planned on regearing to 4.56's, but now I'm wondering if I should scrap the RC lift and buy a better one. I'm not even sure what exact size kit it has, but it has fixed upper and lower replacement arms, new springs, no spacers and the twin stabilizer set-up. Looks to be 3-4" of lift. Any ideas on what to look for? I will check today to see if the track bars are also after market or the original, and if they are adjustable. I feel like the wheels/tires have to go even though the wife loves them, but not sure about the lift. Is this the type handling I should expect if I want to own a lifted jeep? In case it's not obvious, this is a "mall crawler", so offroad performance is not really a priorty. Hate if you must, but I have a trail only rig that gets trailered to and from, so this one is just for cruising with the family. Thanks in advance guys.... and gals

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Last edited by dawgfan77; 07-23-2013 at 05:01 PM.. Reason: pics
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Unread 07-23-2013, 02:24 PM   #2
SoK66
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Sounds like it needs to go on an alignment rack for a settings check. Until you do you'll just be guessing. Might also have the tires balanced at a qualified shop that knows big tire setups like that. Look for somone with a Hunter Road Force balancer.

AS for changing suspensions, many of us aren't fans of those budget lifts like RC, simply because they deliver about what you pay for. Swapping it out for a quality lift is not a bad idea, in my experince you'll end up replacing one piece at a time eventually.
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Unread 07-23-2013, 02:27 PM   #3
orviston
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i know the feeling.. see my post on suspension. My rig was like a carnival ride and i am still working out the kinks. last check though the shop that did it had me at 3 degrees castor.. but I think what would be best from all the great input here is 5.. not sure if it would solve everything.. however, I am pulling that kit and going with a much better one and take into account the castor issue there. I don't have time for all the bs and running around it has taken.

So read my post.. I am sure the feedback there applies and there were no "haters"
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Unread 07-23-2013, 03:06 PM   #4
brianjw
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Ditch the crappy lift and 20" wheels.

Then decide if you want to run it stock or run a mild lift (2-2.5") and some more narrow 33" tires that will handle a little better.
If you want to run 35s and handle great it's going to cost you. I have the AEV 3.5" lift (one of the better road handling lifts) and I still had to install about $1300 in steering components (not including my labor) to really make it handle solid. But I use the jeep pretty hard too.

If you want something that looks goo and handles well I would consider the AEV 2.5" lift with geometry correction brackets, an adjustable front track bar, AEV wheels (good offset and not too wide), and maybe some 285 tires or something? Your caster will be where it should be, springs and shocks will be well tuned, tires won't grab ruts in the road too bad etc.
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Unread 07-23-2013, 03:08 PM   #5
brianjw
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On second thought, one easy thing to try is install the AEV geometry correction brackets to fix the caster. Install synergy's 911 suspension bolt kit and make sure everything is properly torqued. It may work out okay.
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Unread 07-23-2013, 03:17 PM   #6
GauchoMark
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that seems like a LOT of lift for 35's.

I don't want to sound snobbish or anything. Economy lifts have their place. But an economy lift is not going to ride great anyways, and I can't imagine RC's 4" lift (which is FAR from complete) is not going to be terrible at speed.

IMO, you would be better off returning it to stock and planning a build. For 35's you can get by with a budget boost lift even. All you need is 2-2.5" of lift.
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Unread 07-23-2013, 05:23 PM   #7
dawgfan77
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Quote:
Originally Posted by brianjw View Post
On second thought, one easy thing to try is install the AEV geometry correction brackets to fix the caster. Install synergy's 911 suspension bolt kit and make sure everything is properly torqued. It may work out okay.
Thanks for the info, gonna try these before I start over. Any pics of them installed?
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Unread 07-23-2013, 05:34 PM   #8
dawgfan77
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I snapped a few pics o the lift components. I think I have the RC 3.5" kit. I also looked at a buddy's 2013 with the Mopar 3" kit 35's and they look about the same height. Just to clarify, my plan is 17-18" wheels and 33's. I'm not going back stock.
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Unread 07-23-2013, 05:43 PM   #9
dawgfan77
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After a closer look. think those are factory UCA's.... but not sure? And the track bars as well, any thoughts? I did find a few things that I'm not happy with:
1)rear track bar bolt is contacting the coil spring-easy fix
2)it looks like the LCA bolts were torched out or maybe cut off with a grinder, hard to tell without removal, but there appears t be significant damage behind the cam bolts in the LCA axle-side mounts

This was actually a very reputable local 4x4 shop, which surprises me
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Unread 07-23-2013, 05:45 PM   #10
brianjw
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Quote:
Originally Posted by dawgfan77

Thanks for the info, gonna try these before I start over. Any pics of them installed?
Now I'm just ASSUMING that your lift doesn't have any adjustable control arms or brackets on the front and that is why the caster is off. If so, that attributes partially to the flighty feeling. There are the AEV brackets.
http://www.aev-conversions.com/shop/...ckets-frt.html
The obvious alternative is adjustable lower control arms of your choice. I recommend these for the reasons you can read on the website. Especially if its not off road much, it will get your caster back where it should be and keep the factory ride with stock control arms.

Here is the bolt kit.
http://www.synergymfg.com/Synergy-Su...t-p-28601.html
You can also buy the upper control arm bolts. The advantage here is that the stock jk suspension bolts are threaded the full length, as the bolts pass through the metal sleeves inside the bushings. In short order (especially with 35s) the threads destroy in the inside of those sleeves and create extra slop which will in turn help oval out the mounting holes sooner. New bolts, properly torqued are a good idea. These can be retained and reused with another lift so you're not throwing the money away.

Now in all fairness, you may still just be trying to polish a turd (crappy lift). Most good lifts will raise the track bar mount on the axle, and flip the drag link mount on the knuckle. I BELIEVE (im not a RC expert by any means) your lift just uses a frame side track bar drop and a drop pitman arm on the steering box. The stock steering box isn't real strong to begin with and a longer arm puts more stress on the steering shaft.
To go further into this, if you're using the stock ball joints, tie rod, drag link and track bar, they are all a little weak for 35" tires anyway. The stock parts are designed to flex and give some by nature. I chased down sloppy parts on my 2012 for months with my 35s and finally replaced basically everything up front with HD aftermarket parts, and was finally satisfied. My wife was afraid to drive it for some time.

And judging by the pics alone, it looks like the wheels have a ton of backspacing. With the wheels and tires further out, it's placing more stress on the factory parts and just making things worse.
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Unread 07-23-2013, 05:45 PM   #11
dawgfan77
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Quote:
Originally Posted by orviston View Post
i know the feeling.. see my post on suspension. My rig was like a carnival ride and i am still working out the kinks. last check though the shop that did it had me at 3 degrees castor.. but I think what would be best from all the great input here is 5.. not sure if it would solve everything.. however, I am pulling that kit and going with a much better one and take into account the castor issue there. I don't have time for all the bs and running around it has taken.

So read my post.. I am sure the feedback there applies and there were no "haters"
Thanks man, I'll watch them both
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Unread 07-23-2013, 05:50 PM   #12
brianjw
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I see the new pics. There's a drop pitman arm, and the track bar raised on the axle. The control arms are stock but with cam bolts. The cam bolts suck because they don't allow enough adjustment and they can loosen.
The rear axle track bar bracket doesn't look well re-enforced but that's typical rough country.
I have no idea what they did to the control arms with the cam bolts, made a mess I suppose! Lol

I'll let some others chime in b
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Unread 07-23-2013, 05:51 PM   #13
dawgfan77
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Quote:
Originally Posted by brianjw View Post
Now I'm just ASSUMING that your lift doesn't have any adjustable control arms or brackets on the front and that is why the caster is off. If so, that attributes partially to the flighty feeling. There are the AEV brackets.
http://www.aev-conversions.com/shop/...ckets-frt.html
The obvious alternative is adjustable lower control arms of your choice. I recommend these for the reasons you can read on the website. Especially if its not off road much, it will get your caster back where it should be and keep the factory ride with stock control arms.

Here is the bolt kit.
http://www.synergymfg.com/Synergy-Su...t-p-28601.html
You can also buy the upper control arm bolts. The advantage here is that the stock jk suspension bolts are threaded the full length, as the bolts pass through the metal sleeves inside the bushings. In short order (especially with 35s) the threads destroy in the inside of those sleeves and create extra slop which will in turn help oval out the mounting holes sooner. New bolts, properly torqued are a good idea. These can be retained and reused with another lift so you're not throwing the money away.

Now in all fairness, you may still just be trying to polish a turd (crappy lift). Most good lifts will raise the track bar mount on the axle, and flip the drag link mount on the knuckle. I BELIEVE (im not a RC expert by any means) your lift just uses a frame side track bar drop and a drop pitman arm on the steering box. The stock steering box isn't real strong to begin with and a longer arm puts more stress on the steering shaft.
To go further into this, if you're using the stock ball joints, tie rod, drag link and track bar, they are all a little weak for 35" tires anyway. The stock parts are designed to flex and give some by nature. I chased down sloppy parts on my 2012 for months with my 35s and finally replaced basically everything up front with HD aftermarket parts, and was finally satisfied. My wife was afraid to drive it for some time.

And judging by the pics alone, it looks like the wheels have a ton of backspacing. With the wheels and tires further out, it's placing more stress on the factory parts and just making things worse.
you are correct sir, nothing adjustable. And it does have a drop pitman, however the track bar bracket it raised on the axle end. I'm gonna order the AEV brackets and bolts 1st, and go from there. Thanks again
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Unread 07-23-2013, 05:52 PM   #14
dawgfan77
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Quote:
Originally Posted by brianjw View Post
I see the new pics. There's a drop pitman arm, and the track bar raised on the axle. The control arms are stock but with cam bolts. The cam bolts suck because they don't allow enough adjustment and they can loosen.
The rear axle track bar bracket doesn't look well re-enforced but that's typical rough country.
I have no idea what they did to the control arms with the cam bolts, made a mess I suppose! Lol

I'll let some others chime in b
Oh, so those are the factory LCA's also?
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Unread 07-23-2013, 06:49 PM   #15
222Doc
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looks like it has a drop pit arm. Needs to go.

But it also has a raised track bar. Dropped pit arms is not a good idea on a Jk. You get much better handling with a Drag link flip and gets some good tres and put the stock pit arm back on. there is a lot of loose part in the stock tie rod and drag links. just check a new jeep see how easy they rotate, kinda just fall over. gets some 1ton like ones and see how tight they are.

since you are at 3.5 I would just work to get it right have fun. Fact is at 3.5 and 35 your Jk is at a very good height to run trails.

get rid of that drop pit arm. go flipped if you are staying over 3.5. I would.
Get some adjustable arms or brackets. to set the front right.

its a matter of time you will replace most of it and some of it more than once. its a jeep
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