correct me if im wrong but they do not make coilovers for the awd system and the front suspension is different from the rwd to the awd so you cant use the rwd coilovers on an awd gs.

anyway im trying to talk to road magnet about their springs and hopefully i can get a set soon to try. also they are only about an hour from me so i'll see.

 

Let us know what they say. I'd be willing to install them on my car if there was no vibration. Does anyone know what effect changing the suspesion will have on your vehicle if it's CPO?

 

Suspension doesnt have any effect on your warranty unless it directly affects/damages another component. Under the Mognussen Act (However you spell it) they have to prove that the modification was responsible for whatever damage caused, otherwise your CPO is still CPO.

 

correct. however they will always find a way to relate it back to the part

anyway i will keep you updated on what road magnet says. i emailed them to ask them a few things so i'll see what they say.

 

Yea.......but thats a whole different story....

 

[QUOTE=IXI187IXI;4178769]correct me if im wrong but they do not make coilovers for the awd system and the front suspension is different from the rwd to the awd so you cant use the rwd coilovers on an awd gs.

QUOTE]

True, but for those with rwd coilovers already installed, I would try to readjust the height setting to see if it makes a difference BEFORE i swap back to stock (to rule out the obvious before spending $$$ for another setup, install).....Who knows, the vibration might just be a lowering height issue.

 

but thats the point im trying to make. anyone with a rwd gs with coilovers will not be able to help you out as they dont have vibrations and people who have the awd gs cant help you out because they dont have coilovers because the rwd coilovers do not fit.

im pretty sure the apparent issue is with the axles. i asked on my other forum about this type of issue and i got this answer also

 

I agree with you on testing a set of RoadMagnet awd designed springs, keep us posted on the results.

 

I've had my AWD GS for over 3 years and it has been lowered with staggered wheels for most of that time. After all of the research and time spent in different shops/dealers the car has specific vibration issues. Even when my car was 100% stock I still felt more vibration at idle versus a stock RWD. I also, experienced the vibration (very subtle side to side wobble) from a stop and go (up to approx. 15mph). The RWD GS rides so much smoother!

If you do a search on the web you'll find other auto mfg's with AWD systems (Chrysler, Volvo, Mazda, etc.) in which owners have experiences of unsolved vibrations.

Bottom line, it's the design of the vehicle (powertrain and suspension). Modifying the suspension may amplify the vibrations? The GS300 AWD is not a good car to modify and expect that the ride will be nice and smooth. I believe the 2006 IS/GS are the first generations of Lexus AWD sedans. With that, you can expect first generation issues. Probably a nice AWD luxury sedan to modify would be an Audi becasue they've been manufacturing AWD vehicles for a long time and aftermarket parts (lowering kits) are more readily available.

I'm going to put my car back to stock (if I decide to keep it) or trade it in before the factory warranty expires. I don't like the vibrations either! I regret buying the GS AWD model, I didn't expect these types of vibration issues.

 

the fact that some people get vibrations and some dont, you can make a rational judgement on all AWD GS'

 

We have no quantitative means of measuring the level of vibration, it's subjective. If you ask my wife, she thinks the car rides perfectly fine. There are people out there who have the vibration(s) and it doesn't bother them. These people may not think there's a vibration problem with their car.

I have closely observed the dynamics of my GS AWD since day one. I know for sure, it always had an idling vibration (while in drive with the foot on the brake pedal) issue. Whenever I put the car in neutral, it's smooth as silk, I can't even tell the car is running. The "Lexus Master Technician" indicates that it's normal for the AWD because of the drive train (no detail). Therefore, there was nothing they can do to "fix" the issue.

Due to subtle variability in the automotive manufacturing process, not all GS AWD's are made exactly the same. However, with the Lexus GS being manufactured in one of the most state of the art automotive production facilities and managed on the TPS (Toyota Production System), you would expect the output of their fully lean six sigma production line to manufacture cars that operate exactly the same. My assumption is that the issues of vibration has to do with the design of the GS AWD.

Moving forward (if the GS AWD continues), the design of the chassis, suspension and powertrain will most likely be improved to resolve subtle vibrations. As for now, because it's not a safety issue they may just let it slide until the next model change.

If I were to do it all over again I wouldn't have bought a GS AWD because I like to lower my vehicles and put larger wheels and tires. Therefore, I do not recommend the GS AWD to anyone who is planning on modifying the suspension. Actually, even if they're not planning on modifying the suspension, I would strongly recommend looking at other luxury AWD sedan options.

 

Sorry to hear about the car and the issues you are experiencing. I just bought a GS300 AWD, and I will eventually lower it and add wheels like I do with pretty much all my cars.

I have to say though, Toyota has been manufacturing AWD sedans, wagons, compacts, and sport cars for a long time. They have extensive experience in WRC with AWD Celicas, Corollas, etc... I don't think Audi or any other manufacturer has an engineering advantage. I also don't buy what your master technician said about AWD in general being a problem. I've been in numerous lowered AWD cars, and many were Toyotas. No issues like you are describing. I myself have owned and lowered an AWD car and added wheels.

I'm not trying to refute your personal experiences... there must be something about this particular model that is causing the issue...

 

make sure you get a camber kit

 

Like I said, I have a 2007 GS350 AWD and I have Tanabe DF210 on them and they do not vibrate at all.....and the ride is just like stock and Handle is much better. I am not sure what is this vibration talk all about.....hmm

 

1.5 years with my NF210's on my AWD. Still no vibration or clunking that some folks speak of. I'm still a firm believer of having wheels re-balanced or a car re-aligned. I think some folks might also be waiting too long to get their lowered cars aligned. It doesn't take a whole lot of miles to develop uneven tire wear on a heavy car that's AWD that has decent torque...specially if you are driving it on uneven roads. For some guys with aluminum wheels, it's easy to bend your wheels on potholes without noticing...which is another reason your wheels should get rebalanced. 30-40 series tires don't over a whole lot of protection.