Never ending warped rotors - G35

[Impreza]

Yes. The pressure of the hydraulic system is controlled by the driver and the pressure on the front left and front right should be the same. But having bad shocks/struts affect the stopping distance of your vehicle. So instead of braking normally you are now pressing the brake pedal harder trying to stop, this you put more pressure on the brake pedal which push more pressure on the brakes.

You can read up here. http://www.kyb.com/knowledge-center/...orn-shocks-do/

[R. Mutt]

Originally Posted by BoostedBB6

Suspension will have 0 impact on brake components seeing as they are in fact attached to the bottom of the struts.
alignment can cause a vibration, but when you change your rotors and drive 10k with no more issue but comes back and again is remedied from rotors its very clear the issue is not the suspension. Not to mention G35's were known for this problem from day one and the easy fix was non-OE pads.

I disagree because of my personal experience. I should have been more specific when I said suspension: steering geometry. There are two main reasons for brake vibration. The first is steering geometry issues and the second is installation or hub run-out issues. Both of these are components of a vehicle's suspension. Steering geometry issue can develop from hitting a curb or pot hole. I have had this very issue on my evo 9.

In my case the suspension was way out of alignment due to steering geometry issues and I developed groves in my rotors as they wore unevenly over time. Again note...this happened over time and wasn't something noticeable immediately. Of course I didn't know this at the time and as such couldn't resolve the issue despite trying different pad compounds until the car got another alignment as it turns out that the settings had deviated substantially due to another issue. This also resulted in wearing down a set of Michelin PSS down to almost no tread withing a 1.5 year time span and less than 10,000 miles. So yes suspension can have a huge impact on brakes among other components.

As per this being a G35 specific issue...you'd know more than me. However the fact remains that suspension can and will have a severe impact on braking. Moreover the OP stated

steering wheel vibrates under braking, strong enough to be alarming on the highway

So once again...sounds like suspension related issue to me.

[BoostedBB6]

Originally Posted by Impreza

Yes. The pressure of the hydraulic system is controlled by the driver and the pressure on the front left and front right should be the same. But having bad shocks/struts affect the stopping distance of your vehicle. So instead of braking normally you are now pressing the brake pedal harder trying to stop, this you put more pressure on the brake pedal which push more pressure on the brakes.

You can read up here. KYB Americas | What worn shocks do (or don?t do)

Only way that makes enough of a difference in a average road going vehicle is with a completely obliterated suspension system and is not applicable to this situation at all.
In theory, yes having to push harder on the pedal to stop would cause increased heat, but AGAIN this is a road going car that's been maintained with all needed items. It does not have completely blown shocks allowing for such a drastic weight shift that he has to brake harder.

Far reach even if they were blown to say that this is the case as the springs are far more load bearing and don't simply fail.

Only time this would be a measurable effect on a car would be in a track situation under repeated heavy loadings.

This idea that the suspension (shocks) are so bad that they cause rotor warping (fyi, there not warped) is as applicable as saying a clean car gets better fuel milage than a dirty one because it has less wind resistance and weight. It is TRUE but it is so minute that there is no measurable quantity to show such a minor thing. Shocks being blown will kill stopping distance tho, but only because you no longer are able to maintain a consistent contact patch between the tire and road, not the brakes.

[BoostedBB6]

Originally Posted by R. Mutt

I disagree because of my personal experience. I should have been more specific when I said suspension: steering geometry. There are two main reasons for brake vibration. The first is steering geometry issues and the second is installation or hub run-out issues. Both of these are components of a vehicle's suspension. Steering geometry issue can develop from hitting a curb or pot hole. I have had this very issue on my evo 9.

In my case the suspension was way out of alignment due to steering geometry issues and I developed groves in my rotors as they wore unevenly over time. Again note...this happened over time and wasn't something noticeable immediately. Of course I didn't know this at the time and as such couldn't resolve the issue despite trying different pad compounds until the car got another alignment as it turns out that the settings had deviated substantially due to another issue. This also resulted in wearing down a set of Michelin PSS down to almost no tread withing a 1.5 year time span and less than 10,000 miles. So yes suspension can have a huge impact on brakes among other components.

As per this being a G35 specific issue...you'd know more than me. However the fact remains that suspension can and will have a severe impact on braking. Moreover the OP stated
So once again...sounds like suspension related issue to me.

OP has not abnormal tire wear issues, is a dealer service car with everything up to date and is driving a car KNOWN for brake issues causing pad transfer to the rotors due to the pad compound being used.

IF it has ANYTHING to do with the suspension the vibration at speed would be felt even after replacing calipers/rotors/pads, it would not be gone for 10k and then come back.

This has nothing to do with suspension, it is the pads. G35's had this issue, its well known. Hell, take a die grinder with a scuff cookie on there and just rip it across the rotors and make a fresh surface for the pads to contact and go for a drive, the vibration will be gone but will return after a short while as the pad material re-transfers to the rotor.

Unless your EVO 9 had its hubs changed when you had it aligned you had no brake issues. Caster, camber, toe and thrust angle are the standard things adjusted during an alignment, none of which have any impact on brake wear or function but they WILL destroy tires. You can disagree till your blue in the face, but the fact of the matter is there is no suspension geometry change that effect rotor to pad wear or alignment. If you find one I would love to know about it so I can better do my job

[BoostedBB6]

Steering angle, wheel alignment, shocks, springs, unicorns will not do ANYTHING to the brakes of a car to increase wear.

On a G35, the caliper, hub and rotor are all ridged mounted to the knuckle. This knuckles moves as one (effecivly) solid unit. No matter how you change the steering angle or suspension you so not change how the pads contact the rotor, or the angle of the rotor to the caliper. They remain ridged mounted to the knuckle.
So no matter what you are lead to believe, having a bad alignment will not cause groves in your rotors. The rotor is mounted to the hub, the hub is mounted to the knuckle and the caliper is mounted to the knuckle.
With this setup, the ONLY way to do any damage to the rotor would be to damage the hub that's mounted to the knuckle. IF you managed to do this then you would have a rotor that is no longer aligned with the caliper and could cause issues HOWEVER on a vehicle like a G35 it would cause a significant wheel wobble, vibrations at almost ALL speeds and unless the guy has smashed both hubs equally, would not duplicate on the other side of the car like it has.

[cunninglinguist]

Maybe whoever put the wheels on over tightened the lug nuts.

[entrax]

for what its worth:

- i believe the dealer's consensus was definitely out of true rotors from diagnosis 2 days ago.

- steering vibration only happens when brake is applied. as a previous owner of a tercel with solid front discs small enough to fit 12" wheels on, i can relate to the owner regarding the steering vibration due to bad rotors. i saw the brakes recently, and there were no grooves found. to be clear, there is zero vibration at all when not on the brakes. you can drive this thing with your pinky finger nails with fake nails attached to it...until you need to brake. i read stuff and i believe it's because the hotspots/high spots as boostedbb6 has mentioned aren't in the same exact spots on the rotor from left to right, so if you imagine the pad contacting the rotor in slow motion, there's spots where the pad grabs the rotor more, but it's not the same left to right.

- tires were purchased new sometime around early 2015, michelin ps all season. i took his summer wheels off and put on his winters (separate sets) for him back in october and i noted even minimal wear across the tread. i think the fronts wore down 1/32 and rears by 2/32, or the other way around, no abnormal camber wear. car was driven to okanagan twice in the summer up and down coquihalla. rotors were fine then. it's probably been 4 months since those drives and only now has it been an issue

i believe the tires being okay deems the alignment decent, i'll ask if alignment has been done recently. hub run-out can be eliminated as this would have caused issues from day 1.

[fliptuner]

So at this point it's just a matter of cutting the rotors and trying out some (recommended) aftermarket pads.

[ncrx]

Damn with all that money spent
Could have gone with a nice 2 piece floating rotor and different pads.
A 2 piece rotor deals with expansion better

I dont know g37's, but torque wheels properly, check the front wheel bearing.
Dragging brakes slowly, as well as standing on them after a lot of usage tends to cause pad deposits. Shorten up those brake distances and use firmer brake applications.

[entrax]

@fliptuner yeah, seems like it

buddy took a photo of invoice. tax in wa $2501.10

wheel bearing is part of the hub = $336
each caliper = 459
that's already $1254 without the stillen rotors and pads or labour or tax.
i didn't bother asking for the 2nd page lol.

if you count the raybestos + lordco rotors + pads 6 months before that...the entire ordeal has been approx $3k in the last year. i keep telling him to just buy an mr2.

looks like the consensus has been:
cut rotors, non-oem pads, torque carefully, firmer brake, shorter time on the brakes. that should be more than enough advice to see if it makes a difference. maybe he was too easy on it after spending so much on it.

[cdizzle_996]

Well I paid $153us for both front Centric Parts 120.42095 rotors, paired with Akebono ACT1287 that were $53us and I havent had an issue in 10k.

I drive the car, I dont baby it. When I purchased it, it had "drilled and slotted" rotors and hawk pads that nearly rattled my shoulders out of their sockets.

[twitchyzero]

arent' getting half decent rotors (ie centrics) cheaper than turning the rotors?

[underscore]

If he's driving the car very little, and braking extremely gently all the time, then my guess would be build up on the rotors that's not getting cleaned off due to the lack of hard use.

[The_AK]

Originally Posted by trollguy

what's wrong with lordco rotors?

the fact that some of their off-brand parts cost the same as dealer is one of them

[extracrunchie]

I don't even bother resurfacing the rotors anymore, they cost practically the same.

Way easier to just replace them then to take the rotors off and get a shop to resurface it from a DIY'er perspective.

[SpuGen]

Originally Posted by entrax

i keep telling him to just buy an mr2.

*Ahem*
I know of one for sale.

[cooke24]

does this g35 have the brembos?