6080prado

Just picked up a 2005 GX470 with a bit over 100K and excellent service history. I had actually been shopping for a 100 series Land Cruiser to replace my 80 series. But GXs are far more plentiful and affordable, so I had been researching them as well. Got a good price on the GX and am happy.

I went in figuring I would have to do some suspension work as the handling and feel was less than impressive on the test drive. It felt both harsh and also floaty. Nothing scary, but clearly not right. Having spent several hours on this site and others, I felt I had a good idea of what I was getting into. I figured it was likely the shocks and, if so, would just go with 4Runner or even OEM. At over 100K, any shock is going to be pretty tired at this point. I had tested the ride height and it seemed to be functioning properly.

However, now I am leaning toward the bigger issue being the airbag system. Speed bumps feel like a kick in the butt. But in the High setting, it goes over them like a pillow. The system doesn't seem to lose air. I have also tried cycling the ride height to re-set the system, but it didn't seem to improve anything.

I'm not opposed to going to conventional springs. But before I go that route, I'm also not opposed to spending some money to get the stock system working right - if I know I can get it working right. And given the stories I read on this site about Lexus dealers not being able to troubleshoot these systems, I certainly don't want to blindly throw money at a system I may end up replacing. I think part of the problem is both my shocks and airbag system have issues and I am having a hard time determining how each may effect the other.

So here are some possibles courses of action I may take and I would love to hear your thoughts:

1) Using spacers under the ride height sensors, raise the ride height about .5-1" to see if this improves the harshness.
2) Replace the OEM shocks with 4Runner shocks as it is a minimal investment and will help me isolate issues by removing the OEM shocks from the equation. Plus, I could still use these if I switch to coils.

Basically I'm looking at bang for the buck. Since I have never driven a new GX or a GX converted to coils, I really don't know how good the OEM system can be or how it compares to and aftermarket setup. But I don't mind spending $1000 or more to get a good suspension. But I don't want to spend $1000 or more and still have issues.

Also, I have purchased a Techstream but have not hooked it up. Can the Techstream read suspension codes or is this only done with the OBDII jumper?

Thanks and appreciate the knowledge base here.

gxman1

Congrats of the purchase.
I love mine.

I will let other give you suggestions on the suspension, if you read RC's posts he discussed these in details. However, I like your questions and possible solutions. Please do keep us posted, as many including myself will need to address the suspension very soon.

Far as techstream it will not give you the codes.

RC where are you, this post is up your alley.

YoshiMan

Welcome aboard!

I was in the same boat, and was looking for a Landcruiser 100 or LX470 to replace my FJ62, but they all were either overpriced or totally beat to hell.

The GX was a perfect fit!

6080prado

Thanks for the warm welcome.

I still would have liked a 100 series, but for the same price you can get a GX that is 2-3 years newer with 25-50K less miles. I worried that the GX wouldn't be big enough, but it is really close to the size of my 80. I also had a 60 prior to the 80. Believe it or not, I am one of the few people who prefer the 62 to the 60. I would have readily traded my round headlights for FI, auto, and power windows and locks!

stiles_s

Sounds like you're going to do new struts and shocks at a minimum? if so, I'd go ahead and replace the rear shocks with something like the Bilstein 5100s (or b6s) and see if the truck does a better job staying off of the bump stops. if not, then I'd bump the rear height up a bit. Really easy -- either spacers for a bigger lift, or just raise the adjuster up in the "slot" it rides in. 10min each side.

For me, new shocks and some subtle adjustments made all the difference in rear ride comfort.

6080prado

You're really hitting on my conflict. I generally wouldn't think shocks would make much of a difference in terms of keeping the truck from bottoming out. But with this set up on the GX there seems to be a lot of inter-relationship between the airbags and the damping. You're right though - I pretty much need shocks anyway. If I knew the shocks alone would fix the problem, I might actually spring for OEM. But in this case, I'd better start off with the cheaper alternatives.

stiles_s

You can easily reverse the order and bump up the rear ride height a bit. This will help, for sure. I've been there.

Skooch under the rear of the truck and see how much distance you have between the bump stops & the axles at rest. My guess is you have very little. And, you'll see evidence of contact based on a clean spot on the top of each side of the axle.

Adjust the height by sliding the height adjusters in their little slots an even amount per side. Get it so you have ~2" of space. See if that helps.

My theory is that the "active damping" in the OEM rear shocks tries hard to keep contact from happening between the bump stops and axle. And, that this active damping "wears out" pretty quickly in the overall lifespan of the shock, making axle contact far more common.

If you want to continue experimenting on the cheap, here's one more suggestion: un-plug the pigtail connection to the rear shocks; both sides at the same time you raise the rear. This turns of the "brain" trying to auto-adjust the rear shocks (along with obeying the soft<>sport setting on the center console). I've been running like this (rears unplugged, fronts plugged) for the last 10+K miles and prefer it. The front shocks are "dumb"; just a 4-way adjustable shock. No smarts. The rears are where the smarts are, hence the $$.

6080prado

It's like you're psychic Stiles!

After work I had about 30 minutes before I had to take my son to soccer practice. It was the soccer field parking lot that had the speed bumps where I noticed the bottoming out. So I really wanted to go back to the same area after making a change. Since I don't have any spare shocks laying around, I did a quick adjustment to the sensors. I was pinched for time, so it was a very rough adjustment. They had been set at almost the bottom of the adjustment slot. So I moved them to about the middle, which was likely a touch too high. But I figured it would be a good comparison.

The results were positive. It really minimized the bottoming on the speed bumps and I think the higher spring rate from the higher psi seemed to actually help the handling a bit.

That said, it still isn't right. It still feels under-damped, so new shocks of some sort will be forthcoming. The big question is which ones. I think I can actually get the stock ones through amayama.com for like $350 (plus a substantial wait time). I'm not opposed to paying that, I just don't know if they will feel any better than a 4Runner or aftermarket shock. I'm also curious if anybody has looked into OEM Prado shocks. I believe other than the "Grande" version, they all have a conventional suspension. Anybody know anything about those shocks?

stiles_s

Try one more 10min experiment: un-plug your rear shocks. You can reach in there and do it without jacking up the truck. 10min tops. tuck the pigtails under something so they don't catch on anything. Go drive over the speedbumps and see if you see improvement. I'd bet $1 that you do. Not going to be a permanent fix for 100k-mi shocks, but I bet it'll help.