LX570 feels unstable on freeway and clunking noise (7 Viewers)

[neh20711]

Hi all,

My 2013 Lx570 feels unstable on the highway. Feels like the rear end is loose. Any thoughts?

There is also a clunk sound going over speed bumps almost like the spare is hitting something. I removed the spare but same issue.

Sensor lift with spacers in all 4 corners and panhard bar correction installed.

Thanks!

 

[yOHda]

Check to make sure your rear body mounts aren’t rusted.

 

[neh20711]

Check to make sure your rear body mounts aren’t rusted.

Don’t see any rust on the mounts.

 

[bloc]

Double check that panhard correction and the two primary bolts for the rod.

 

[clrussell]

Panhard correction issue?

Have you have a proper alignment after the PCK? VGRS reset also

My 200 drives like wet dog s*** after I put the PCK on it. Tail wags all over.

If an alignment doesn’t fix mine I’m cutting it off and putting the panhard back in the stock location.

 

[afgman786]

Panhard correction issue?

Have you have a proper alignment after the PCK? VGRS reset also

My 200 drives like wet dog s*** after I put the PCK on it. Tail wags all over.

If an alignment doesn’t fix mine I’m cutting it off and putting the panhard back in the stock location.

Are your pan hard bolts tightened correctly? A loose pan hard bolt will have your axle shift side to side just enough to feel like terrible trailer away

 

[TeCKis300]

Hi all,

My 2013 Lx570 feels unstable on the highway. Feels like the rear end is loose. Any thoughts?

There is also a clunk sound going over speed bumps almost like the spare is hitting something. I removed the spare but same issue.

Sensor lift with spacers in all 4 corners and panhard bar correction installed.

Thanks!

Did the symptom start after the PCK install? Which PCK do you have, Eimkeith or DrKDSS? And which bolt position are you running?

How much total rear lift (sensor and techstream offset) do you have?

Max AHC sensor lift in the rear with full sensor slot adjustment and techstream adjustment is ~1.5". The minimum PCK relocation is ~2". So the PCK will generally overshoot the amount of correction even at max AHC sensor lift.

If you're much less total lift sensor, the relocation might create more sagitta / side to side motions than it solves. If you're running the top bolt position (~3"), that will be much much more correction than necessary and definitely create issues.

 

[clrussell]

Are your pan hard bolts tightened correctly? A loose pan hard bolt will have your axle shift side to side just enough to feel like terrible trailer away

Yes. Even moved down to the middle hole and it helped “some”

Good info in the post below the one I’m quoting.

Mine is the weld on bracket that’s pictured In teks post.

I tried the top hole first, terrible. On lower hole now and it still drives less than good.

Going back to the factory location soon.

I’m on a very small lift. Maybe 2”. I’ve made an effort to keep mine very low.

 

[clrussell]

Did the symptom start after the PCK install? Which PCK do you have, Eimkeith or DrKDSS? And which bolt position are you running?

How much total rear lift (sensor and techstream offset) do you have?

Max AHC sensor lift in the rear with full sensor slot adjustment and techstream adjustment is ~1.5". The minimum PCK relocation is ~2". So the PCK will generally overshoot the amount of correction even at max AHC sensor lift.

If you're much less total lift sensor, the relocation might create more sagitta / side to side motions than it solves. If you're running the top bolt position (~3"), that will be much much more correction than necessary and definitely create issues.

View attachment 3919052

View attachment 3919053

Thank you for this.

I’m going back to the factory bolt location when I have the chance to crawl under and mess with it.

 

[TeCKis300]

Thank you for this.

I’m going back to the factory bolt location when I have the chance to crawl under and mess with it.

Curious how much lift you had?

Asking as I'm about to install mine. With a 1.5" sensor lift, I'll be overcorrecting by .5" and wondering if that's going to create more issues than it solves.

A little history, when I previously lifted 1", I still had great side to side stability. Once I bumped that up to 1.5" sensor lift, I could tell the stock geometry had more sagitta, with more side to side motion on big bumps. Still not bad, but if really paying attention, it was there. More-so when towing with 1200 lb tongue weight as that uses more suspension travel on the same bump.

Interestingly, as I go up in tire size with more sidewall, the lateral movement is no longer there as the sidewall absorbs all the sagitta.

So back to my question, my rig handles really well at the moment, so wondering if I really want to do this.

 

[neh20711]

Ok update:

I took out the dr kdss kit and put it back to factory. Good news is that that issue went away. Bad news is I now have a terrible noise but only on low and normal, not on high mode.

I did drive it like 15 feet to a flat area with everything disconnected. Hopefully didn’t mess anything up.

Edit: video link



Thanks!

 

[bloc]

How can I upload a video?

Easiest method is stick it on YouTube or another hosting site and attach the link.

 

[neh20711]

Easiest method is stick it on YouTube or another hosting site and attach the link.

Video link

 

[neh20711]

Ok update:

I took out the dr kdss kit and put it back to factory. Good news is that that issue went away. Bad news is I now have a terrible noise but only on low and normal, not on high mode.

I did drive it like 15 feet to a flat area with everything disconnected. Hopefully didn’t mess anything up.

How can I upload a video?

Thanks!

Let me know if the link has any issues

 

[bloc]

I don't think that has anything to do with the panhard rod.. Haven't heard that before but I agree it does not sound good. The frequency of the sound compared to wheel rotation would have me looking closely at the driveshafts.. all 4 U-joints, the grease guard around the front joint on the rear shaft.. hell I'd even be checking that all the lug nuts are tight. That is a significant sound.

 

[GrouchyTech]

I don't think that has anything to do with the panhard rod.. Haven't heard that before but I agree it does not sound good. The frequency of the sound compared to wheel rotation would have me looking closely at the driveshafts.. all 4 U-joints, the grease guard around the front joint on the rear shaft.. hell I'd even be checking that all the lug nuts are tight. That is a significant sound.

That’s what I’m hearing, too. The frequency of the sound is matching pretty closely to the driveshaft bolts or the ears hitting a heat shield. After that I’d look at are the rotor backing plates/shields.

This sounds completely different from how it was described in the original post in this thread. And this noise shouldn’t cause any handling issues—unless it’s a red herring.

 

[tbisaacs]

That’s what I’m hearing, too. The frequency of the sound is matching pretty closely to the driveshaft bolts or the ears hitting a heat shield. After that I’d look at are the rotor backing plates/shields.

This sounds completely different from how it was described in the original post in this thread. And this noise shouldn’t cause any handling issues—unless it’s a red herring.

Would also suggest if that doesn't isolate anything, would consider locking the CDL and disconnecting one of the driveshafts to make sure you dont have a R&P issue

 

[neh20711]

Found the issue. The plastic clip broke off of this piece above the engine skid. Anyone know the clip part number or can I just cut it off?

 

[GrouchyTech]

I’m circling back to the “unstable on the freeway” part. Are you still experiencing that? The heat shield should have nothing at all to do with that.