MPLexus301

iTrader: (3)

Wow ok...makes sense. I have always heard about shocks and struts discussed as two different things so I never drew that parallel. Thanks for clearing it up! I guess this won't be as costly as I was thinking. Springs for $225, Shocks for $300, Ball Joints for $120, and the Daizen bushings are like $30...hopefully I should be good for a long time to come with these updates.

Thanks for the info buddy.

farkas

iTrader: (5)

Sounds like you are good to go! But do not forget the strut mounts as that may have been your original problem and the rest of the goodies are maintanence items.

CK6Speed

iTrader: (1)

^^^^ What he said. All said you don't need struts from the dealership since you already bought the KYBs. But that still doesn't address the condition of the strut top mount, or some call it top hat, or pillow mount. That is the piece with the 3 bolts in a triangular position that mount the entire strut assembly to the cars strut tower. The stock one has a nice beefy rubber bushing up there to keep it quiet and dampen vibration. If that is worn out that could cause some of that clunking you mention. Personally I haven't know too many of them that has worn out, but you never know. You need to inspect its condition when you disassemble the OEM strut/spring combo because you will need to reuse that top strut mount. Or you might as well buy new ones up front then you don't have to disassemble and reuse the old ones, just assemble the new KYB and Tanabe springs with the new top strut mount, then install it as one package. The KYB shocks will not include a top mount so you'll have to do one or the other.

farkas

iTrader: (5)

Right ON!!!!!! VW's are notorious for killing strut mounts but Lexus and Toyota's are not as hard on them. They do go bad and you never know what that front end has gone through before MPLexus301 bought the car. I know he babies his ride but he has only had it for a short time now!

McKrevice

iTrader: (1)

that's WAY better than 250.00 each. If I could get them for that much I'd do it in a heartbeat.

RON430

In a strut type suspension, the spring is damped by a component that is actually part of the suspension operation. A suspension that merely has a shock absorber doesn't need it for the suspension to operate, it is just dampening the oscillations of the spring. For all intents and purposes, don't sweat the details they accomplish the same function and the terms are pretty much used interchangeably today.

Daizen bushings are a rigid polyurethane not rubber. In a stock suspension the bushing is an engineered rubber and provides some "give" as well as being much more forgiving on wear due to its compliance. The poly bushing eliminates the flex and has the effect of making the suspension component that is going through it operate directly without the flexure of the bushing. Different strokes for different folks but I don't care for solid bushings on the street for several reasons. I am sure you have looked through all the threads for impressions on the solid poly bushings. I don't know of any manufacturer that uses solid poly bushings OEM any place in their suspension.

MPLexus301

iTrader: (3)

Thank you again for the continued knowledge and information! I really appreciate it. May I ask why you don't like them? How do they impact ride quality?

Thanks again.

CK6Speed

iTrader: (1)

For me it made my SC400 very stiff. The best I can describe it as it transferred a lot of vibration back into the steering wheel, but didn't do much to increase the road feedback. In comparison to my BMW with sports suspension which is pretty stiff, that suspension transferred a lot of road feedback, but not so much a feeling of vibration since it still used rubber bushings.

Anyway, I too would pass on the poly bushings for the upper and lower control arms. The only place I may use the is for the sway bar bushings and steering rack bushings.

RON430

Factory engineers can play around with the durometer of the rubber used and adjust suspension response and NVH issues. Eliminating the flex from bushings is a great way to increase response. If that is what you want. Back in the olden days, we made replacement bushings, it isn't hard, including body mount isolators out of things like bronze. That was for racing and it worked pretty well, like I said, it isn't difficult. If you are designing an aftermarket suspension piece, like a sway bar, that has a different diameter than stock, the most cost effective way to provide a bushing is to machine it from plastic. It is a lot cheaper than paying for the molds and getting rubber ones. Besides, it is a lot easier to "specify" polyurethane than to have to really figure out what durometer and composition rubber is needed. As the comment made elsewhere, bimmer has this annoying habit of getting suspensions to work prety well without solid bushings.

The reason you need the bushing, lets take the sway bar, is because the bar is turning inside the bushing. If you made the bushing out of steel it would be really stiff and really noisy. It would also wear pretty quickly. Whichever one is softer wears. If the bushing is harder than the bar, then the bar wears, and vice versa. The bar or the bushing will wear as the bar turns. With a rubber bushing, besides getting the vibration isolation, you also have something with compliance and as it wears, it still presses against the bar taking up the slack. Heck, just temperature variations can cause gaps and the rubber just compensates due to its compliance.

Any kind of solid bushing is going to wear from the friction. So you have people looking at things like filled plastics, typically gaphite to provide some permanent lubrication. But it is rarely enough so people start taking the thing apart and sticking some grease in there or actually drilling for a grease fitting and forcing some grease in there.

The benefit from the solid type bushing isn't enough for me to want to fool with them on the street. There are people that feel they are worth it, just not me. The Sportivos and the TRD blues came with rubber bushings and I have never felt that they needed compliance taken out of their operation. Even with that, as I posted before, anything I did to improve the handling of the second gen GS came at the expense of ride. It is surprisingly sensitive in that regard.

UDel

How did everything go with your new suspension pieces installed? Did it stop the creaking noise and make your ride better? I think my strut mount or top hat might be the culprit for the noise when I go over bumps, especially speed bumps. I am still trying to diagnose it.

MPLexus301

iTrader: (3)

I never saw your post and ended up looking back on this thread for another member, I apologize.

After having my new suspension for about a month now I can gladly report that the car is FAR smoother and more composed in all driving conditions than it was before. The suspension handles imperfections and bumps much better than the stock setup and the reduced ride height has tightened things up a bit as well.

My new suspension solved all of the problems I originally posted about and I am very happy now

GS4_Fiend

iTrader: (22)

Did it stopped the noise you were having with before? I put on KYBs GR2 Struts/Shocks, and still makes noise in the fronts. Let me know.

MPLexus301

iTrader: (3)

My crunching noise is gone now but I am not sure if that is because of the ball joints, tie rods, or shocks. Sorry buddy

farkas

iTrader: (5)

That noise is probably the strut towers....Did you change yours MPLexus301 ? If you did not then the second possibility is the ball joints. GS's are hard on them!

GSteg

iTrader: (15)

This is why I'm only going to replace the caster arm bushing. I'm leaving the OEM upper and lower control arm bushings alone. I dont need the car to ride rough, but I do need the caster to last longer than what OEM can provide me. Too bad our design is terrible relative to other companies out there.