problems with stability when accelerating or decelerating

[seraph037]

I have 2004 kj Rocky Mountain edition 2wd, and have started to notice that when I accelerate I feel the rear end shimmy to the right, when I let off it shimmy to the left. I'm not talking about just a little bit either, it's kinda crazy, I've never felt a vehicle do this before. Is it torque steer? I know that I need to replace suspension all around, but is that really the issue? I rode with a friend behind my jeep on the hwy, and I can actually see it happening, it is quite a spectacle, it looks like my jeep just likes to shake it's rear end. Any suggestions or information would be much appreciated, and btw I apologize if I have posted in the wrong place. Thanks

 

[ltd02]

Not a mechanic, but first thing I'd check are the rear tri-link ends and LCAs. Get under there and see if the end bushings are okay. Mine does some funky stuff when cornering and I know mine are on their way out. I get a thunk over minor bumps due to the center BJ on the tri-link too. Seems like if one end was particularly bad then it would kick out when Acc or Decel.

 

[John3seventeen]

Probably the rear lower control arm bushings are shot. Also check the rear upper control arm bushings and ball joint.

 

[seraph037]

Will do. I'll check back if no luck. Also, if I go to the parts house and tell them I want "Old Man Emu"when I get my shocks&struts, are they gonna understand what I mean, or are they more likely to think I want OEM? I think, after reading the FAQs here, that OME is the way to go... but I'd be lying if i said i know what that means.

 

[CzarKJ]

Will do. I'll check back if no luck. Also, if I go to the parts house and tell them I want "Old Man Emu"when I get my shocks&struts, are they gonna understand what I mean, or are they more likely to think I want OEM? I think, after reading the FAQs here, that OME is the way to go... but I'd be lying if i said i know what that means.

If you are talking about the A's parts houses they wont carry OME most likely. I am assuming you are not lifted but I would still order online from Jeepin by al or whereever you can find them. Are you planning on changing just shocks? Because the springs are most likely worn just as much as the shocks. Better to replace both at the same time. And if doing that... a lift is the same cost as stock height... just sayin haha:ROFLJest:

 

[seraph037]

Checked rear bushings and ball joints they are Ok, but Im not sure if that alone would affect the ride as much as I am experiencing even if not. I'm ready to order parts for suspension all around, but still don't understand the meaning of the phrase " old man emu" can anyone actually explain that, or is it just repeated because it was said so many times? I don't doubt the wisdom, just the reason. Again, what does OME actually mean?

 

[CzarKJ]

Checked rear bushings and ball joints they are Ok, but Im not sure if that alone would affect the ride as much as I am experiencing even if not. I'm ready to order parts for suspension all around, but still don't understand the meaning of the phrase " old man emu" can anyone actually explain that, or is it just repeated because it was said so many times? I don't doubt the wisdom, just the reason. Again, what does OME actually mean?

OME is a brand/company that produces suspension parts. They are Australian.

 

[tommudd]

Checked rear bushings and ball joints they are Ok, but Im not sure if that alone would affect the ride as much as I am experiencing even if not. I'm ready to order parts for suspension all around, but still don't understand the meaning of the phrase " old man emu" can anyone actually explain that, or is it just repeated because it was said so many times? I don't doubt the wisdom, just the reason. Again, what does OME actually mean?

OME is a brand of springs and shocks that lifts the KJ 2.5 inches if you use the 927 front springs and 948 rear springs. You must use the springs and shocks as both are worn out if you have over 50,000 miles.
If the rear end is " dancing or moving around" then lower control arms are bad

 

[seraph037]

Thanks for the advice guys. I appreciate your help.

 

[TwoBobsKJ]

OME is a brand of springs and shocks that lifts the KJ 2.5 inches if you use the 927 front springs and 948 rear springs. You must use the springs and shocks as both are worn out if you have over 50,000 miles.
If the rear end is " dancing or moving around" then lower control arms are bad

^^^^That.

You'd be surprised how a 'little' movement fore and aft in those rear lower control arm bushings can dramatically affect the lateral stability of the Liberty. Think about it: A 1/4" movement on each side means there's the potential for the axle to be angled up to 1/2" left or right - which will shoot your Jeep to the side like a horse that doesn't like riders.

Change the lower control arms before you do the lift (or at the same time) so your new suspension is nice and tight.

Bob

 

[LibertyTC]

Type in your VIN number here to see any outstanding recalls. Many Rear LCA were recalled.
Link: https://customerconnect.custhelp.com/app/jeep/recall_detail/a_id/18737
Free lower control arms with new bushings is a good thing!
My Jeep would jump to the left on acceleration, and move right when decelerating.
I pressed in new bushings into the rear LCA and all is good. This was before the recall.

 

[dogran999]

^^^^That.

You'd be surprised how a 'little' movement fore and aft in those rear lower control arm bushings can dramatically affect the lateral stability of the Liberty. Think about it: A 1/4" movement on each side means there's the potential for the axle to be angled up to 1/2" left or right - which will shoot your Jeep to the side like a horse that doesn't like riders.

Change the lower control arms before you do the lift (or at the same time) so your new suspension is nice and tight.

Bob

For sure you should find the cause of the issue before changing anything new. My KJ has two perished bushes on the rear A mount which caused just the symptoms you described. Pulls to one side on acceleration, the other on braking.

A GOOD wheel alignment shop will check the bushes first before doing any adjustments and should be able to tell you what needs replacing. If they don't have the bushes order them and then get them fitted before you do the lift..... A lifted broken suspension is still a broken suspension.

 

[kuench]

I had this symptom. It turned out to be a loose bolt.