Bump steer and tie-rod end flip (1 Viewer)

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Way too much squat in the back and/or lift in the front. AHC is not damping the movement very well. I know you have the pressure set low for a reason - you might consider airbags in back to keep the rear end up and push the front down a bit when you accelerate.
 
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That thing goes from normal Cruiser to Carolina squat every time you hit the gas 😂 Put sum dub deuces on at thang bruh.
 
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I’d guess your inner tie rods are also shot. At least the driver’s side based on your description.

They SEEM fine from here but I haven't pulled the driver's boot back yet to visually check it. Passenger was fine - I replaced the bellows and outer tie rod last weekend before I realized just how bad this issue was!

TRE's are tapered, pretty sure. No way to flip them easily (I looked at them when I did my lower ball joints with this thought).

What is your toe-in set to? It should be zero. Also, check the bushings on your steering rack.

TREs are tapered. The 'normal' way to flip them is to drill out the knuckle to not be tapered and add a tapered insert from the opposite direction. I was hesitant to do this to start with and as it turns out, it doesn't look like I'll need to worry about flipping the ends after all. If I were going for a mega lift then it might have been worth it but I have no intentions of going any higher than this.

Toe is damn near zero. On my street cars I usually like to run 1/8 or so toe in for stability. Once I have my steering rack reattached, I'll mess with the alignment again. I've been also dealing with trying to center the steering wheel with small adjustments of toe but have been struggling to get it to a constant state...now I know why.

Way too much squat in the back and/or lift in the front. AHC is not damping the movement very well. I know you have the pressure set low for a reason - you might consider airbags in back to keep the rear end up and push the front down a bit when you accelerate.

Agreed, it is excessive, I think. The damping works fine in bound but seems very weak in rebound. Not sure why that is. I had AHC set to the second from the softest setting. I have the king upgraded rear AHC springs and a winch hanging off a winch plate and it still tries to do a wheely when I punch it. It doesn't wobble and bounce and oscillate like worn shocks do but there is a lot of pitch aft under accel and seemingly less under braking.

Once I get new bushings on the rack, I'll break out Techstream again and make sure the pressures are where I left them. The behavior certainly seems like AHC pressure too low but I double and triple checked them last time I made an adjustment. My TBs are pretty much cranked to max thanks to the winch, rock rails, and extra crap inside.
 
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Have you tried repeating the test with the AHC knob turned to Sport?

If it is the same, I personally wouldn't suspect the AHC/TEMS system.
 
They SEEM fine from here but I haven't pulled the driver's boot back yet to visually check it. Passenger was fine - I replaced the bellows and outer tie rod last weekend before I realized just how bad this issue was!



TREs are tapered. The 'normal' way to flip them is to drill out the knuckle to not be tapered and add a tapered insert from the opposite direction. I was hesitant to do this to start with and as it turns out, it doesn't look like I'll need to worry about flipping the ends after all. If I were going for a mega lift then it might have been worth it but I have no intentions of going any higher than this.

Toe is damn near zero. On my street cars I usually like to run 1/8 or so toe in for stability. Once I have my steering rack reattached, I'll mess with the alignment again. I've been also dealing with trying to center the steering wheel with small adjustments of toe but have been struggling to get it to a constant state...now I know why.



Agreed, it is excessive, I think. The damping works fine in bound but seems very weak in rebound. Not sure why that is. I had AHC set to the second from the softest setting. I have the king upgraded rear AHC springs and a winch hanging off a winch plate and it still tries to do a wheely when I punch it. It doesn't wobble and bounce and oscillate like worn shocks do but there is a lot of pitch aft under accel and seemingly less under braking.

Once I get new bushings on the rack, I'll break out Techstream again and make sure the pressures are where I left them. The behavior certainly seems like AHC pressure too low but I double and triple checked them last time I made an adjustment. My TBs are pretty much cranked to max thanks to the winch, rock rails, and extra crap inside.
If you can move one tire left/right when it’s in the air, then the inner is gone.
 
They SEEM fine from here but I haven't pulled the driver's boot back yet to visually check it. Passenger was fine - I replaced the bellows and outer tie rod last weekend before I realized just how bad this issue was!



TREs are tapered. The 'normal' way to flip them is to drill out the knuckle to not be tapered and add a tapered insert from the opposite direction. I was hesitant to do this to start with and as it turns out, it doesn't look like I'll need to worry about flipping the ends after all. If I were going for a mega lift then it might have been worth it but I have no intentions of going any higher than this.

Toe is damn near zero. On my street cars I usually like to run 1/8 or so toe in for stability. Once I have my steering rack reattached, I'll mess with the alignment again. I've been also dealing with trying to center the steering wheel with small adjustments of toe but have been struggling to get it to a constant state...now I know why.



Agreed, it is excessive, I think. The damping works fine in bound but seems very weak in rebound. Not sure why that is. I had AHC set to the second from the softest setting. I have the king upgraded rear AHC springs and a winch hanging off a winch plate and it still tries to do a wheely when I punch it. It doesn't wobble and bounce and oscillate like worn shocks do but there is a lot of pitch aft under accel and seemingly less under braking.

Once I get new bushings on the rack, I'll break out Techstream again and make sure the pressures are where I left them. The behavior certainly seems like AHC pressure too low but I double and triple checked them last time I made an adjustment. My TBs are pretty much cranked to max thanks to the winch, rock rails, and extra crap inside.
If you're trying to center the steering wheel, it's really easy to pull it and center it. At least it is on my '99 LC. I have no steering sensors to worry about and the airbag clock spring has instructions printed on the front for clocking it. It took me five minutes after I replaced my rack, and that's because I was distracted talking to my girlfriend.
 
If you're trying to center the steering wheel, it's really easy to pull it and center it. At least it is on my '99 LC. I have no steering sensors to worry about and the airbag clock spring has instructions printed on the front for clocking it. It took me five minutes after I replaced my rack, and that's because I was distracted talking to my girlfriend.

On a VGRS equipped 06 LX470, it’s also possible to center the steering with TechStream, although neither will hold the setting with a bad set of steering rack bushings.

 
Have you tried repeating the test with the AHC knob turned to Sport?

If it is the same, I personally wouldn't suspect the AHC/TEMS system.

I haven't tried that as it took me several tries to get a decent video of the dynamic toe, and I was worried my nieghbors were going to come see what all the noise was about! :confused:

If you can move one tire left/right when it’s in the air, then the inner is gone.

Usually true, but in this case, the bushings are gone allowing the whole rack to lift off the cross member as I rock the tire side to side. The inners may be gone but problem number 1 is the bushings, then I'll see if there's any more play in the tie rods.

If you're trying to center the steering wheel, it's really easy to pull it and center it. At least it is on my '99 LC. I have no steering sensors to worry about and the airbag clock spring has instructions printed on the front for clocking it. It took me five minutes after I replaced my rack, and that's because I was distracted talking to my girlfriend.

I usually just do a quick half turn on each tie rod until I get it happy, but this time, I'd adjust and it would be centered for a couple hundred miles, the I'd pull out of a gas station and straight ahead would be 15 degrees to one side again. Was driving me insane! But the rack bushings being toast explains why that was happening. I hope, anyway.

On a VGRS equipped 06 LX470, it’s also possible to center the steering with TechStream, although neither will hold the setting with a bad set of steering rack bushings.


I've done this a ton of times as well. I usually have my VGRS disconnected, but after an alignment, I reconnect it and do the VGRS re-center procedure.
 
Alright well, back to the drawing board. I got the bushings changed out today and it hasn't fixed the thing. It's better, no two ways around that, but still bad enough to constantly squeal the tires when I stomp on it. I tried with the ahc knob set to max stiffness and it made no difference either.

We threw it on the lift and pulled and pried on every damn thing. It's extremely clear that the bump steer gets really bad as the suspension reaches full extension - a full 3.5 inches of toe in when the tires are off the ground. Even so, I shouldn't get anywhere near wheelie-ing the LX so I can't see that being the issue.

The one thing we noticed is that both sides have some interesting play in the steering rack. The inner and outer tie rods have no play in them, but the internal rack piece that the inner tie rods attach to shows decent up/down movement when we're pushing and pulling on the wheels. My best guess at this point is that the rack is screwed up somehow. I have no idea how that even works but there's literally nothing else I can come up with that could be wrong.

So, I've ordered a new steering rack from Detroit Axle. Hopefully, that eliminates some of the ridiculous toe in I get under throttle. I'm also planning to double check my AHC pressure tomorrow sometime.

This is becoming a HECK of a headache.
 
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At this point, best bet is to lower back to stock height and AHC pressures to see if the issue gets better.
 
the internal rack piece that the inner tie rods attach to shows decent up/down movement when we're pushing and pulling on the wheels. My best guess at this point is that the rack is screwed up somehow
I had the same issue and needed to replace the rack.


So, I've ordered a new steering rack from Detroit Axle.
BAD idea. As $hitty as it is to replace the rack, you only want to do it once. Good chance the DA rack starts leaking within 10k miles. OEM or bust.
 
As I noted in a previous comment, I had the same issue and needed to replace the rack.
BAD idea. As $hitty as it is to replace the rack, you only want to do it once. Good chance the DA rack starts leaking within 10k miles. OEM or bust.

Very much wanted an OEM rack but all the toyota parts sites show none in stock and part discontinued.

At this point, best bet is to lower back to stock height and AHC pressures to see if the issue gets better.

You're not wrong. I really want to make this work though, I'm just not sure why I'm having such issues when no one else does. Makes for a frustrating battle with my LX.
 
You're not wrong. I really want to make this work though, I'm just not sure why I'm having such issues when no one else does. Makes for a frustrating battle with my LX.
But, how do you know your mods aren't the root cause of the issue? Or the issue is miniscule at stock suspension settings and the AHC lift with low pressures makes it epically worse?
 
Very much wanted an OEM rack but all the toyota parts sites show none in stock and part discontinued.

 
But, how do you know your mods aren't the root cause of the issue? Or the issue is miniscule at stock suspension settings and the AHC lift with low pressures makes it epically worse?

I don't, but how can I be the first person in 100 history to come across this issue? Are the things I've done more extreme than anyone else? Just seems crazy to me.



And yet when I go to mcgeorge toyota, I get this page


Which tells me a different part number and it's discontinued. How did you get to that page? Unfortunately, it's already been shipped.

this book will answer all your questions.

Amazon product ASIN 0912656468

I already own it actually. Bumpsteer may be the issue here but everything I've read says it should be minimal. Plus, may other people run much larger lifts than I do....at least, I think they do.
 
you've upset the corner weight balance by lifting and eliminating the rake. That overloads the rear springs. Anyone that watches your vid would say the rear is under sprung and we know this because you've upset the front rear ratio. Whether the fix for that means air bags, thicker springs, progressive springs, higher air pressure, higher fluid pressure- doesn't matter.

the non ability to maintain front alignment through the front end top to bottom elevation change under full acceleration is a result of tie rod angle changes. The jalopy effect or your bump steer.
The steering issue is a separate one from the under sprung rear end.

bump steer is never minimal with that much of an elevation change from full squat to full extension on the front end. MAybe if you had a tie rod end that was 3 feet long.

the steering and the rear squat are separate issues to fix, but combined result in your issue.
 
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you've upset the corner weight balance by lifting and eliminating the rake. That overloads the rear springs. Anyone that watches your vid would say the rear is under sprung and we know this because you've upset the front rear ratio. Whether that means air bags, thicker springs, progressive springs, higher air pressure, higher fluid pressure- doesn't matter.

the non ability to maintain front alignment through the front end top to bottom elevation change under full acceleration is a result of tie rod angle changes. The jalopy effect.
The steering issue is a separate one from the under sprung rear end.

bump steer is never minimal with that much of an elevation change from full squat to full extension on the front end. MAybe if you had a tie rod end that was 3 feet long.

the steering and the rear squat are separate issues to fix, but combined result in your issue.

Alright, so just for clarity - you're saying adding (I think I measured) 3/4 inch of rake back should mostly solve my lift issue? That's quite an easy thing to do. This would have the same effect as stiffer rear springs.

As for rear end being under sprung - I'm already on springs that are like 40% stiffer than OEM. I have no interest in going to airbags. More AHC pressure might help?

As for the bump steer - I agree it's extreme change but that's also a huge amount of bump steer. Best I can figure is the extra droop just takes all the original engineering and throws it out the window. I just can't believe no one else has dealt with this. This isn't exactly super long travel suspension here.
 
I can't comment on ahc pressure. I avoid air and fluid springs.
an easy exercise for anyone is to lower the front end incrementally and check how it behaves. You will quickly see what happens, the more you lower a front corner the the more weight transfers from the opposite rear corner.

everyone else does deal with this, they just go to a tolerable level that they're happy with. If you never full out step on it and see the front end raise up as part of your regular driving then no one really cares what's happening.
I'm pretty sure most are just going in a straight line any way at full throttle so as long as the truck maintains a straight line then they're good.
That's where you need a new rack.

the rear spring thing I'd just lower the front. I don't even think it matters which one you do first, both need to be done. Rack and weight shift.

I can say that mine lifts up a fair bit. I can feel it and see it, the steering change in that straight line of travel is there.
Getting far outside the ride height as measured by the FSM you really are throwing out all the stock specs and going it alone. I pay more attention to rod and cv angle.

I haven't really thought about the arc of travel on the rod end and what's acceptable to a LC. Obviously it's more than a small track car. I doubt no one's seen a front end lift up like yours under throttle.
 
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