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Old 10-01-09, 02:12 AM   #1
skperformance
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Lightbulb front suspension fixes and facts

I have read so much on the front suspension issues for the GS . Unfortunately they have not been correct in many ways in people guessing and not technically knowing how the parts work together.
So here is my take on them.

I have an 03 GS430 with 150 000 KM on it.

Symptoms ,
wandering all over the road.
super light steering at any speed
strong vibration 100km/h and over
front tires howling at 70 km/h
clunking over bumps
clicking when driving or reversing from park (also can be caused by not replacing those small screws on the rotor hubs as they do have a purpose)
rapid tire wear with heavy feathering
some may have bald tires on the inside
Loud howling noise from front end tires
very poor emergency braking
poor gas milage

Fixes
It really starts with 1 as it is the problem that kills all the rest of components.
It is the front caster arm bushings.
When they die your alignment goes to shyt .
The front wheels toe out and the caster goes negative . Causing all of the problems above from one part.
You can replace them with oem's rubber bushings but the suspension geometry is not the best for them and multiplies the pressure. This causes them to fail under hard braking fast as it does not take much. Replace these with urethane and you will be able to go hopefully forever without a repair again.
While you are at it you will have to change the ball joints as well as they will have been stressed by the caster arms unable to take the load and causing the ball joint to be pressed at an angle . They will break and it is not because the ball joints are weak . It is because the suspension is out of alignment and cannot compensate the load of the arms .While you are at it check the tie rods but they can handle the odd angles from the arms.

Once done the car will need to be aligned as well .

You will now have a front end that is rock solid.
If checked properly and nothing else is worn it will no longer wander on the highway .
The tires will wear properly .
The brakes alone is the biggest benefit as it feels like you added a BBK form the amount of grip .
The steering will feel real tight and not over powered . So the thread about unplugging the PS ecu is not needed and the car can be driven properly .
No more clunking over bumps as the ball joint is not taking the bump but the bushing is.
Vibrations gone as the wheels axis is straight and not sticking out which causes the vibrations.
Gas mileage goes up as the wheels are now pointed straight and you are not holding them like a shovel being pushed down the road .

All this from a daizen urethane front control arm kit $100 and a pair of OEM lower ball joints $180 plus alignment $60 .

I love driving my wife's car again and so does she.

I did not install the upper control arm or the lower arm that the ball joint sits on as they are fine and it will tighten up the front end more than i want.
Some people complain about it being to stiff but just doing the caster arm alone is all i needed. I could not care less about wasting the other bushings.

So good luck and stop blaming the ball joints or the power steering as problems when they are not. The cars just need some TLC .

added info.


I also forgot to add my mileage went up by 20% as i am no longer shoveling my wheels down the road.
I was getting 420km per tank and now get 500 (city/hwy) to 600km (more on the hwy) a tank.

With my 70 liter tank
I was getting
420km =16.7 liters per 100km = 14mpg
and now it is
500km =14 liters per 100km = 16mpg
600km =11.7 liters per 100km = 20 mpg

Only other variables are an HKS exhaust and motul 8100 oil until i do a cold air intake and it should be in the 600 range all the time.
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Last edited by skperformance; 10-09-09 at 09:04 PM.
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Old 10-01-09, 10:53 AM   #2
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Quote:
Originally Posted by skperformance View Post
I have read so much on the front suspension issues for the GS . Unfortunately they have not been correct in many ways in people guessing and not technically knowing how the parts work together.
So here is my take on them.

I have an 03 GS430 with 150 000 KM on it.

Symptoms ,
wandering all over the road.
super light steering at any speed
strong vibration 100km/h and over
front tires howling at 70 km/h
clunking over bumps
clicking when driving or reversing from park (also can be caused by not replacing those small screws on the rotor hubs as they do have a purpose)
rapid tire wear with heavy feathering
very poor emergency braking

Fixes
It really starts with 1 as it is the problem that kills all the rest of components.
It is the front caster arm bushings.
When they die your alignment goes to shyt .
The front wheels toe out and the caster goes negative . Causing all of the problems above from one part.
You can replace them with oem's rubber bushings but the suspension geometry is not the best for them and multiplies the pressure. This causes them to fail under hard braking fast as it does not take much. Replace these with urethane and you will be able to go hopefully forever without a repair again.
While you are at it you will have to change the ball joints as well as they will have been stressed by the caster arms unable to take the load and causing the ball joint to be pressed at an angle . They will break and it is not because the ball joints are weak . It is because the suspension is out of alignment and cannot compensate the load of the arms .While you are at it check the tie rods but they can handle the odd angles from the arms.

Once done the car will need to be aligned as well .

You will now have a front end that is rock solid.
If checked properly and nothing else is worn it will no longer wander on the highway .
The tires will wear properly .
The brakes alone is the biggest benefit as it feels like you added a BBK form the amount of grip .
The steering will feel real tight and not over powered . So the thread about unplugging the PS ecu is not needed and the car can be driven properly .
No more clunking over bumps as the ball joint is not taking the bump but the bushing is.
Vibrations gone as the wheels axis is straight and not sticking out which causes the vibrations.

All this from a daizen urethane front control arm kit $100 and a pair of OEM lower ball joints $180 plus alignment $60 .

I love driving my wife's car again and so does she.

I did not install the upper control arm or the lower arm that the ball joint sits on as they are fine and it will tighten up the front end more than i want.
Some people complain about it being to stiff but just doing the caster arm alone is all i needed. I could not care less about wasting the other bushings.

So good luck and stop blaming the ball joints or the power steering as problems when they are not. The cars just need some TLC .
glad u got your issues resolved....just for future reference on these below.

daizen urethane front control arm kit $100

where did u get them from? link?
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Old 10-01-09, 08:54 PM   #3
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+1
I mentioned the caster bushing being a key root cause of the ball joint issue as described to me by a Lexus dealership, but people would rather blame ball joint lubricant. Hopefully your post will help turn the tide and people will start thinking about the entire front suspension system. What this means is - don't replace the ball joints without replacing the caster arm bushings also.
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Old 10-01-09, 09:15 PM   #4
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Interesting thread.. Thanks for sharing!

Btw.. I don't think they would sale the bushing only, they sale the whole control arm. Not anymore at least.

Changing the bushing can be a real PITA for these too.

Last edited by GS4_Fiend; 10-01-09 at 09:24 PM.
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Old 10-02-09, 01:13 AM   #5
skperformance
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sakataj
the daizen kit i got from TM engineering in 1 week to Canada.

Toyota probably sells the whole arm only . The daizen bushings are not that hard to install. Just need a ball joint press borrowed for free from a local auto parts store to press it out. 2 hours max to replace the bushings themselves. I changed mine plus all 4 sway bar links and the steering rack ones in 4-5 hours.
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Old 10-02-09, 12:02 PM   #6
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Does anyone have pics of the caster arm bushings-what part of the control arm is being mentioned here? I just changed by Ball joints and tie rods but stil get a slight clunk on my driver side wheel- funny thing is caster aligtnment is out of spec on that side and could not be brought any tighter.
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Old 10-02-09, 12:20 PM   #7
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Quote:
Originally Posted by skperformance View Post
sakataj
the daizen kit i got from TM engineering in 1 week to Canada.

Toyota probably sells the whole arm only . The daizen bushings are not that hard to install. Just need a ball joint press borrowed for free from a local auto parts store to press it out. 2 hours max to replace the bushings themselves. I changed mine plus all 4 sway bar links and the steering rack ones in 4-5 hours.
i was hoping u werent gonna say that. lol nah i ordered from them a week ago on a tues and had my items by fri so looks like they maybe changing for the better compared to how they used to be.

do u have a part # on this kit?
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Old 10-02-09, 09:11 PM   #8
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Very well said! I have been explaining this in a number of random threads but you completely covered all angles in this post. I have had my GS for just over 9 months and this is the best mod/fix I have done so far.

I had a long back and forth email with a TM engineering guy who mentioned that he tried some time ago to explain this to some CL members but got so much push back from the "online suspension experts" he just gave up trying to explain this very point.

The transformation of the way the GS now feels is awesome and as you mention the braking is greatly improved. The brake energy now goes more directly to the chassis through the urethane bushing that can better handle the stress a 3600 lb. vehicle places on it. Gone is the nasty oscillations/vibrations from any medium to hard braking at any speed. These caster bushings are a Must Do for any GS owner that cares about the proper handling of their car.

Quote:
Originally Posted by skperformance View Post
I have read so much on the front suspension issues for the GS . Unfortunately they have not been correct in many ways in people guessing and not technically knowing how the parts work together.
So here is my take on them.

I have an 03 GS430 with 150 000 KM on it.

Symptoms ,
wandering all over the road.
super light steering at any speed
strong vibration 100km/h and over
front tires howling at 70 km/h
clunking over bumps
clicking when driving or reversing from park (also can be caused by not replacing those small screws on the rotor hubs as they do have a purpose)
rapid tire wear with heavy feathering
very poor emergency braking

Fixes
It really starts with 1 as it is the problem that kills all the rest of components.
It is the front caster arm bushings.
When they die your alignment goes to shyt .
The front wheels toe out and the caster goes negative . Causing all of the problems above from one part.
You can replace them with oem's rubber bushings but the suspension geometry is not the best for them and multiplies the pressure. This causes them to fail under hard braking fast as it does not take much. Replace these with urethane and you will be able to go hopefully forever without a repair again.
While you are at it you will have to change the ball joints as well as they will have been stressed by the caster arms unable to take the load and causing the ball joint to be pressed at an angle . They will break and it is not because the ball joints are weak . It is because the suspension is out of alignment and cannot compensate the load of the arms .While you are at it check the tie rods but they can handle the odd angles from the arms.

Once done the car will need to be aligned as well .

You will now have a front end that is rock solid.
If checked properly and nothing else is worn it will no longer wander on the highway .
The tires will wear properly .
The brakes alone is the biggest benefit as it feels like you added a BBK form the amount of grip .
The steering will feel real tight and not over powered . So the thread about unplugging the PS ecu is not needed and the car can be driven properly .
No more clunking over bumps as the ball joint is not taking the bump but the bushing is.
Vibrations gone as the wheels axis is straight and not sticking out which causes the vibrations.

All this from a daizen urethane front control arm kit $100 and a pair of OEM lower ball joints $180 plus alignment $60 .

I love driving my wife's car again and so does she.

I did not install the upper control arm or the lower arm that the ball joint sits on as they are fine and it will tighten up the front end more than i want.
Some people complain about it being to stiff but just doing the caster arm alone is all i needed. I could not care less about wasting the other bushings.

So good luck and stop blaming the ball joints or the power steering as problems when they are not. The cars just need some TLC .
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Old 10-02-09, 11:05 PM   #9
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Thanks for sharing.. This is good news.. I would get the kit from Sewell since we get a CL discount..

can't wait to do this mod..
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Old 10-03-09, 12:29 AM   #10
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Cool facts... I'm sure this goes for other models as well... Thanks for the input.
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Old 10-03-09, 12:33 AM   #11
skperformance
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The GS has no caster adjustment anyone who said they worked on it is lying to you . The only way to get it in spec is to have a working bushing . Once it is dead ,it out out of spec and replacement is the only fix.

It runs from the lower control arm backwards to under the firewall.
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Old 10-03-09, 01:24 AM   #12
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Wouldn't the camber bolt adjustment affect the caster? Maybe thats what he or the shop meant?
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Old 10-03-09, 12:09 PM   #13
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Camber adjustment bolt is just that, it cannot effect caster.

I would not have said their is no caster adjustment if their was something to adjust.

Caster is the placement of the front to rear wheels. So if it is negative the front wheels are further back or closer to the driver instead of the front bumper.
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Old 10-03-09, 02:43 PM   #14
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What is the caster specs suppose to be do you know?
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Old 10-03-09, 03:54 PM   #15
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OEM spec is 7.55° +/- 0.5°
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