jimutc

Hi everyone,

I'm getting some vibration and steering wheel shake with my '04 GX...I read through a ton of threads, but nobody seems to have the same problem I have a 2004 GX with the differential dynamic damper installed.

About 55-60mph it starts, and shakes the steering wheel back and forth. Sometimes it's completely smooth, but on other road surfaces it shakes. On full "comfort mode," the shake is much worse, but on Sport mode it dampens the shake to about 10% intensity, but it's sometimes still there. This is not bump steer, by the way.

So far, I've done:

-Brakes
-Alignment
-Front hubs
-2x wheel balancing with 2 different sets of wheels/tires
-lubed the drive shaft and prop shaft to fix the clunk (Clunk TSB has not been done)
-changed the power steering fluid
-checked all control arm bushings, ball joints, tie rod ends, and sway bar bushings. All are solid.

I recently jacked up the front end and moved the wheels back and forth by hand. It seems like there is some looseness coming front the inner tie rods. However, I pushed and pulled and can't get a clunk or anything. I think it's coming from inside the steering gearbox. My VIN says it's before ST002-05, so that TSB aka "Steering Flutter" would apply, if it is that.

Has anyone else had the same symptoms and found the fix with this TSB? Or after 104k, are the front shocks due for a change? It does seem to nose-dive a bit on braking, but the shocks aren't leaking or anything. Would worn shocks cause steering wheel flutter on these trucks?


Any help or comments appreciated!

Jim

caha14

I'm running off to an appointment, but just some quick thoughts, and I can elaborate later...

I did have good luck with the flutter TSIB (which includes, among other things, a new steering wheel). My '04 vibrated from the moment I picked it up, and it took several tries to make it smooth as glass (never mind that my former dealer could never balance a tire correctly on the first try).

If the looseness you feel seems to be from the steering rack, that's where my best guess goes, for two reasons: (1) One of the things done to my GX to fix the problem was an adjustment of the steering rack preload and (2) My LS460 had what seemed like an incurable steering wheel shimmy, and after new control arms, etc., guess what fixed it: a new steering rack. The LS and GX are very different animals, but the point is that a bad/loose steering rack can definitely cause a shimmy, and if you are feeling the looseness, it seems like that's where you should look next.

And by the way, welcome to CL!

Booyah

Hmmmm--Im just taking a stab here but you say it mostly goes away when you adjust the shock position, that kind of tells me it has to do with the shocks, and yes 104K, you are Way overdue for all 4 shocks in my opinion. Not sure it will fix your problem but either way you are due for some shocks

jimutc

New observation:

While driving on a perfectly smooth road today, I noticed something. It is perfectly smooth and vibration free while the road crown is 'pulling' it one way or the other. It is also smooth when applying slight pressure one way or the other to counteract slight road crown, or while slightly cornering.

As soon as the road straightens up and crown goes away, meaning it will drive straight hands-free, the wheel starts shaking.

Now it sounds like steering rack wear...not shocks. But the shocks might be contributing, because of my previous observations? How much do your GX's "nose-dive" when braking?

Could I just increase the steering rack preload or install the spring? A new steering wheel setup is $1400!

caha14

I could totally see the shocks contributing, but the impact you notice from changing the setting is - in my opinion - related more to suspension characteristics (stiffness) than anything else, so I am sticking with the rack.

I honestly don't know anything about the GX470's steering rack, though I do know you can adjust the preload and that may be a good next step. On the GX460, which also has a well-documented vibration problem (with its own TSIB), they do change a spring and have color coded springs for various situations.

jimutc

Probably a dumb question, but can the preload be adjusted without replacing that spring?

jimutc

Well, after pulling the front skid plate off....I think I might have found the issue:

I scrubbed the grease off of the front Differential Dynamic Damper, and it turns out it is the superseded part number of 41196-60010. Since I have the vibration between 55-65, this should solve it.

So before I do anything else, I'm installing 41196-60020. I'm not sure why this happened; my VIN designates that I should already have the correct part, and there is no evidence anything being replaced up front (prior accident).

I'll update this thread after replacement.

burny

What Ba Ba Booey said on replacing the shocks

jimutc

Yep, shocks are on the list too

jimutc

Does anyone know how to properly install front OEM shocks?

I had an install manual, but it doesn't say anything about how the actuators line up with the top of the shock. For example, if I manually twist the shock pin to "sport," and install it with the actuator in comfort mode, how does the actuator know how to adjust? There's nothing in the service manual related to this!

Anyone know?

Also, how do I test the actuator to be sure it works?

Thanks for any help




Edit: [it appears I have no idea how the Adjustable variable suspension works....can anyone give me an AVS 101 course or point me in the right direction?]

jimutc

For whomever reads this in the future.....

New front shocks solved 98% of the shaking issues I mentioned above. I'm still installing 41196-60020 per the DL001-08 TSB to mitigate future issues and to get that last 2%.

With the new shocks, It's almost like a new drive! I thought it drove very good before, but now it drives incredible.


It is so much better, I can now certainly feel a difference between the front and rear shocks....rears are next.



Does anyone know if these shocks can be "calibrated?"
-my theory is that if I set the system in full comfort mode, take the actuator off, and turn the shock adjustment clockwise 180° (more sporty), and then reinstall the actuator, that I can adjust the damper "set-point," so I can stiffen the entire ride within the range of comfort-sport settings.

Of course this would depend on which direction I turn the actuator inside the shock. Turning it counterclockwise would soften the entire ride.

Is this possible? Can anyone chime in on how these shock operate?


Thanks, Jim

6080prado

I don't know the answer to your question, but wondered the same thing when I installed mine a couple weeks ago. But then I just assumed the actuators go to a preset position (I.e. 3 o'clock, 6 o'clock) for each setting. So I just fitted the actuators on the top and then positioned them before securing them. I was curious about testing them first. I suppose you could watch them spin as then settings are changed. I don't notice vast differences in the settings, but the damping does seem to change with the different settings.

I have to admit I'm a bit dissapointed after spending $1300. It rides nice, but certainly nothing spectacular, especially given how worn the rears were. I doubt OEM 4runner shocks or Bilsteins would have been noticeably inferior. My fronts actually seemed to have life left in them even after 110k miles.

jimutc

After some tinker around (including Techstream usage), the front shocks can have their "zero" point adjusted, for a softer, or stiffer, ride throughout the comfort-sport setting range.

To change:

Take the actuator off, and rotate the pin inside the shock 180° (clockwise for more sporty), and reinstall the actuator. I wouldn't do more than 180° at a time, as it is very sensitive. There are 16 different settings the shock is adjusted to, and those 16 settings run through only 90° of actuator travel!



Also, I read somewhere else on here that this suspension system, despite being called an "Adaptive Variable Suspension, is NOT active. Well...that is false! The system continuously updates the shock settings based on numerous g-force sensors. This was verified through Techstream.

RCsGX

Damn you could've bought a nice set of used coilovers and had them professional rebuilt for half the cost or you could've bought a new set for a few hundred dollars cheaper.

jimutc

To whomever reads this in the future:

To solve the last 2% of vibration (it was actually was more like 15%), I did a full flush of my power steering fluid, and I changed my power steering fluid reservoir. The old fluid was 10 years old, and when I changed it the first time without changing the power steering fluid reservoir it got all gummed up again by going through the dirty filter. It actually turned almost blue within 100 miles! There is a filter inside the power steering fluid reservoir that needs to be changed, and it wasn't cheap!

Results:

A significantly better driving vehicle, with absolutely zero steering flutter or vibration. The steering actually has a more "cushy" feel and doesn't jump as much over bumps, which makes me believe the new fluid is providing more lubrication and dampening. I couldn't believe the results at first, but over the next couple hundred miles on differing road surfaces, there's no doubt that it was the power steering fluid that is responsible for this change.

Keep in mind while changing your power steering fluid, you have to disconnect the return line and turn the wheels a few times (while jacked off the ground) to get all the old fluid out, and don't let your power steering fluid reservoir run dry!