Uncontrolled / Unstable After Currie 4" and 35s

FarFire70

FarFire70

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I've been waiting to put out a post as I'm still hunting the issue. Been documenting in my build thread but I'm ready to reach out in the technical forum for ideas.

I finished up install of a Currie/Savvy 4" suspension with JJ at all control arms and track bars. I also installed Currie CurrectLync, Front Anti-Rock, and new Woody's DS (front & rear).

Upon first drive after those upgrades, the Jeep was all over the road (a terror to drive). I was in a rush (had to get cleared of emissions testing or lose my registration) so I missed getting the trackbars torqued and also found that I hadn't seated one of the JJ snap rings when I greased the balls before install.

PXL_20230906_143421858.MP.jpg


I re-set this JJ.

I had the wife help me on an alignment with the tires on, using the lugs. After the first drive, I decided to get some aluminum to try again — Confirmed the wife helped get it where I wanted it... (y)

PXL_20230730_154912028.MP.jpg


So this past weekend I had the time to:
  • Torque upper & lower control arms to Currie-provided spec
  • Torque track bars (front & rear) to spec at the axle and frame
  • Anti-Rock to spec (at the bar/arms & the links at the axle) — Best effort on the links at the arms bc I couldn't fit a socket
  • Torqued Rear swaybar (w/ new bushings) at axle, and both ends of the links to spec
  • Lubed the Currectlync joints (tightened up the steering afterwards)
  • Retorqued Currectlync
Note: I did use about a 15-20% reduction in torque specs because I use anti-seize heavily (Northeast USA)

Symptoms:
  • It's ok under 30 MPH on straight roads
  • It feels like it wants to start oscillating left and right to the point that it will have the rear end come around. (This is Not a death wobble or tire vibe — so far as I can tell) Very prominent above 30 MPH or on windy roads.
  • It feels like the rear end is moving around. (That's what I'm feeling but I don't want to ignore something off what I 'feel')
  • It pulls to the right when I change gears (manual)
  • Under power, the oscillating/darty feeling is most pronounced. I can cruise from 40MPH to a stop and it feels fine under cruising & braking.
  • To stay in lane, I feel like I need to 'nurse it' back to center if it gets a little left or right, or risk the ass end coming around.
  • Best I can describe scenarios are above. Other words that come to mind when I drive it: Darty, Floaty, Oscillating, Rear Steer, Boaty

I found it interesting that it felt good (not great) yesterday. I had it up to 70-75 MPH on a 20+ mile trip. It was ok starting on the way to work and then just got worse. I couldn't drive above 50 MPH without worry the oscillating would bring the ass-end around on me.

Like I said - I plan to work on torquing everything on the suspension again. But I would really like any suggestions of things to look out for while I do.
 
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I had a similar feeling with Rancho Shocks. I don't know what it was about my jeep and those shocks, but I did NOT like them on my Jeep. Felt like the whole jeep wanted to rotate around because the rear was doing something different than the front. I changed the shocks and that problem went away. I don't know what it was, but I do know the ONLY change I made was shocks. I went through three or four different sets at that time, before settling on Black Maxes.

I don't know if my issues were as severe as yours though, as I didn't have too much of an issue driving it on the highway or around town. Might be a difference in tolerance to a poor ride, expereince driving the jeep or something completely unrelated.

I would also check my balljoints, and make sure the axles are square under the jeep (measure from the center skid bolt). Look for anything loose. Check torque on all the control arms and trackbars. Since you reduced your torque wrench with anti-seize, bump the torque by 10 pounds, or hit them with an impact. A quick hit with the impact won't get them too much tighter, but the shock may just cause a bolt that has yielded to snap (that has happened to me too and caused some weird handling quirks).
 
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How much toe in do you have? I noticed when I went to 35's from 31's that the 35's liked less toe in. I just kept adjusting incrementally until it drove true and stopped darting. It was between 1/8 and 1/16 that I settled on, if memory serves.
 
Have you checked the rear track bar relocation bracket for tightness, or perhaps for a crack in the axle mount for it?
 
macleanflood said:
Everything torqued with the wheels on and everything on the ground?

-Mac
Click to expand...

Yup - Everything torqued on the ground with the wheels on.

Also not feeling a 'vibe' from the DS and wheels. I've had both - not enough TC Skid drop so a mild DS vibe before the upgrade. Wheels torqued to 100 ft/lbs.
 
AzJeff said:
Also my Jeep came with Correctlync installed and it's under the knuckle not over. Can it be either way?
Click to expand...
It looks like he has a Black Magic Brakes big brake kit. mrblaine will, upon request, drill the new knuckle and tig in a tapered insert so the tie rod can be flipped to the top.
 
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Mike_H said:
I had a similar feeling with Rancho Shocks. I don't know what it was about my jeep and those shocks, but I did NOT like them on my Jeep. Felt like the whole jeep wanted to rotate around because the rear was doing something different than the front. I changed the shocks and that problem went away. I don't know what it was, but I do know the ONLY change I made was shocks. I went through three or four different sets at that time, before settling on Black Maxes.

I don't know if my issues were as severe as yours though, as I didn't have too much of an issue driving it on the highway or around town. Might be a difference in tolerance to a poor ride, expereince driving the jeep or something completely unrelated.

I would also check my balljoints, and make sure the axles are square under the jeep (measure from the center skid bolt). Look for anything loose. Check torque on all the control arms and trackbars. Since you reduced your torque wrench with anti-seize, bump the torque by 10 pounds, or hit them with an impact. A quick hit with the impact won't get them too much tighter, but the shock may just cause a bolt that has yielded to snap (that has happened to me too and caused some weird handling quirks).
Click to expand...

New Black Max on this install:

Front: B8549
Rear: B8563

I've thought that maybe there is something with this set of shocks... I did need to send back the first set of rear shocks from Amazon bc they looked to be used re-boxed. Ordered new rears from Summit.

I plan to check each to see if there is any fluid off any of them and re-torque the shocks too.

I wonder ball joints so need to check them too... I pushed they seemed to have some easy movement but Blaine stated that was normal. I plan to check them but I haven't been great at getting a feel for wear on the 'shake test' in the past to know if it was marginal. I may end up throwing in a new set for assurance.
 
LONGJP2 said:
Axles squared to frame?
Click to expand...

As best I could... Checked it a second time after the first drive. Measured pretty solid but I'm thinking to go get an alignment printout. Did that before the lift for reference. I don't expect they will touch the DA arms but at least I can get a measurement.

Curious on the caster too the print-out would provide.
 
AzJeff said:
Caster wasn't mentioned. Also my Jeep came with Correctlync installed and it's under the knuckle not over. Can it be either way?
Click to expand...

I have an upgraded driver-side knuckle from @mrblaine. So under on the pass & over on the driver.

Installed BMB Big Brakes up front and BMB pads out back. I can say I have NO concern on stopping power. (y) I haven't driven a 35" wheel before but this Jeep stops without any concerns. Still plan to bleed the brakes since these is a couple drives on the full new brake system from the master to the rotors.
 
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97TJNM said:
How much toe in do you have? I noticed when I went to 35's from 31's that the 35's liked less toe in. I just kept adjusting incrementally until it drove true and stopped darting. It was between 1/8 and 1/16 that I settled on, if memory serves.
Click to expand...

Went with 1/8" on 24" aluminum measurements and 3/16" on the tires measurements.
 
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TurboTJ said:
Have you checked the rear track bar relocation bracket for tightness, or perhaps for a crack in the axle mount for it?
Click to expand...

I meant to mention that in my original post as something I need to double check. I did weld in the Currie bracket - So I hope I was smart enough to torque it to spec before welding but I plan to check it... especially because I thought I torqued the track bars before the first drive and was proven wrong,..
 
FarFire70 said:
Middle hole in the new 3-hole arms. Arms are at about 6* above level. I have the shorter links to put in to bring it closer to level.
Click to expand...

Did you have an antirock before you moved to 4" + 35s? Are you over correcting too much while driving? Read this from Blaine. This thread is a great read.

https://wranglertjforum.com/threads/steering-wandering-after-currie-antirock-install.18880/
mrblaine said:
You are reacting to muscle memory and trying to counteract the new to you extra body roll while driving. I see it all the time with folks. You are unfamiliar with it and your brain doesn't like it so it is unconsciously trying to compensate for it by keep the Jeep from leaning by steering into the lean. Try ignoring your brain and the body roll and see what happens.
Click to expand...
 
Anti-Rock
Caster
You can easily check the caster. Should be at least 5*, but 6.5* is better. The less you have the dart’ier it feels
 
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