Steering Wheel Vibration while braking
 

Hey All,

As of late my 370Z steering wheel has began vibrating while braking. Funny thing is that the car was not previously doing this. I've had the car for several months and just passed 1500 miles this weekend.

The car is lowered on KW's and has been that way for about 1000 miles. My rims are stock but powder coated black. However, they've been that way for the last 1000 miles and this issue just started within the last two weeks.

Anyone have any ideas of what the issue may be?

Thanks!

Sounds like warped rotors to me.

This.

I had the same problem.

Definitely.

How does this happen? The car has not been tracked. I've done minimal spirited driving on the streets? Any ideas? Is this a problem for the 370Z?

Does it get better or worse the harder you brake? If it gets better the harder you brake then you may have an air pocket in one of the front calipers. Try bleeding the brakes front and rear and see if it improves. This relates to Sport and Nismo only (fixed calipers).

^^ That is actually my issue, I'll get a little wiggle but then it will go away the more pressure I apply, at higher speeds there's no vibration at all. Can it be as simple as a bubble in the brake fluid?

Yes, has happened to me. It is the downside of a fixed caliper, if one of the pistons on one side is not applying even pressure equal to the opposite side then it is pushing the rotor out of alignment. It happens to me at the track periodically but I just re-bleed and I'm good.

The other cause of out of round is uneven pad deposits, usually from a heavy track session with crappy pads.

Warped brake rotors are probably the single most improperly diagnosed problems on any car today.

I regularly track my car and speak with other drivers and I have never met anyone who “warped” their rotors.

I have experienced terrible vibrations both on and off the track and it has never been the result of “warped” rotors. Usually, it is improper brake in or just crappy pads. Unless you have an actual imbalance in your wheel and brake set up (entirely possible) then you have uneven pad transfer.

Read this link StopTech : Balanced Brake Upgrades .
.

Damn, I just thought of the same article

Yerp.

The problem is def warped rotors, I had the same problem, had them resurfaced by Nissan but still "rewarped". I'm lowered on KW V3's as well & recently switched to 2-piece rotors F/R. Bottom line is Nissan rotors suck

No, the pads suck and you didn't bed them in properly

Ok guy, ya I did bed them in properly, I had both the local Nissan techs & a trusted shop where I get my stuff done say that the front rotors were in fact warped.

I think the problem is that shops throw around the term “warped” as a catchall for any time a car judders under braking(that is the actual term, not “shudders, vibrates, pulses, etc…”).

I have heard well respected auto mechanics use the term “warped” when diagnosing brake judder. The upside to all of this is that, regardless of what you call it, the solution is basically the same. The rotor needs to be resurfaced.

However, if you, with your infinite knowledge gleamed from this site, understands that judder is caused by uneven pad deposits, you can save some money (gasp! That was a long sentence).

How you ask? Most rotor resurfacing will cost you from $25 to $50 per rotor. New rotors will cost you $150. 50 sheets of Garnet sandpaper will cost you $25 and allow you to resurface you and your entire families rotors (and look like a hero) for years to come.

Caveat. You cannot buy Garnet sandpaper at Lowes or Home Depot. Here is the link. 3M? Paper 110N Sheets

Store bought sand paper is aluminum oxide and could make the problem worse.

I understand that this goes against a very common belief on this forum. Trust the guys who track our cars. We go through rotors exponentially faster than anyone who drives on the street. And we don’t lathe or trash our rotors every time we get brake judder.

And we do get brake judder. I have a poorly fitting set of Porterfield R-4 full race pads if your are interested.

Huh. Never heard of the garnet paper. Looks pretty intense.

I believe you 100% in the OP's situation, but just as a footnote, "warping" can happen to cheaper rotors. I had rotors on a car years ago that were badly warped. I think mine may have been caused by a rough curbing incident, so they weren't "warped" per se, but bent. Pretty rare I guess, but possible.

Thanks for the link to the paper. I'm gonna pick some up. With all the hot weather this summer, I've got a slight judder myself.

If you have a 370z with 10" rotors, maybe you will wrap your rotors. A new car with 1500 miles on 14" rotor? Give me a break.

yup, just like how they tell me i need to top off my brake fluid as pads wear. inflate tires to the sidewall pressure, run 100 octane to get more hp from a stock car.

What grit do you use? 80 or 180?

I use 80 grit. I also suggest getting a palm sander or drill adapter.

I use repositionable spray adhesive to attach the sandpaper to the sander.

Hey guys,

I appreciate all of the dialogue. I'm going to take my car to Fontana Nissan's race shop. The guy who runs the show there (Scott) is a very good friend of mine. Plus, they installed my KW's.

Either way, once I know what the issue is (warped rotors or brakes the need to be bled) I'll report back. However. I must say this is frustrating on a fairly new car. If upgraded rotors will prevent this from happening, I think I'll go that route in addition to some upgraded pads.....

Scott is def a good guy, I bought my KW V3's from him as well.

Quick update everyone. I took my car in Saturday morning and the diagnosis was just as everyone suspected, the front rotors are warped. It still a mystery as to why the rotors would be warped when my car has only 1500 miles. The only thing the my Nissan tech Chris mentioned that could have happened is that the dealership where I purchased my 370 hot lapped the car and then sprayed cold water on the rotors during the PDI. At any rate, this is being counted as a warranty repair and they will be ordering me a new set of rotors at no charge. :tiphat:

I'd like to give a big thanks to Scott and Chris at Fontana Nissan for replacing the rotors at no charge!! Id say this is the best dealership in Socal to get work done to your car!!!

soooo am i to believe Fontana Nissan's race shop is full of sh1t too? i love how everyone knows the right answer becasue they track their car......

Told you I knew what I was talking about, Nissan rotors suck.

I wouldn't go as far as saying the totally suck. Again, the damage was premature and likely caused during the PDI process at the dealership. However, I do think that rotors could be a bit more robust. What would happen if your rotors heat up and you end up going through water? What about all of the cars that go through the local car wash. Wouldn't those rotors warp also?

Well it could happen to any rotor that's being used then rapidly gets cooled down, simple science really. Another factor being if it's a high quality material (or not) being used when making them.

If you think you can warp a rotor at 1500 miles, please go right ahead. Unless someone tracked the living piss out of it and then pee on it, there is no way they can warp.

I always pee on my rotors to cool them down, is that wrong?

to warp it 1500 miles, you might need a group of guys giving it a golden shower together

oh yeah, the rotors are giant on the 370. If it is that easy to warp a 370z rotor, the ones on the economy will warp before they drive out of the dealership...

in another thread you didnt know that increasing camber affected toe.... not sure what else you dont know:rolleyes:

If I recall correctly, I put a question mark on it as I wasn't sure since camber on the Z isn't adjustable and I am not sure how that effects toe. What does that have to do with brakes anyway? Pad deposits and warped rotors are completely different things.

nuff said

That's why I always use ? when I don't know.....

http://www.the370z.com/wheels-tires/...racking-3.html

You post matter-of-factly until you are called out...

http://www.the370z.com/wheels-tires/...racking-3.html

used that on #34

sry, back on topic.... at 1500 miles he has warped rotors. is this not the fact? sounds crazy it happened, since i agree the factory rotors are so damn beefy it would take some very aggressive driving to get them hot enough in the first 1500 miles to bend the metal. (im not saying its impossible)

i agree it is possible, but it is extremely unlikely at that mileage, with no track days. pad deposits get diagnosed as rotor warpage all the time. its no different than people claiming high oil temp robs power when the shop manual shows it doesnt do it directly (unless it messes with the vtc?). he got it replaced, thats all that matters.

I appreciate all the dialogue guys. Again, I want to reiterate that the car has not been tracked or even driven in the canyons. This is basically my drive to work on Fridays and the golf course on the weekends.

The only thing that I can only think of is when I wash the car I use Sonax full effect wheel cleaner. Sometimes the over spray of the cleaner lands on the rotors. Do wheel cleaners damage brake rotors? I know that's a far fetched hypothesis, but that's the only other thing I can come with.

BTW, when they change my rotors, should I push for new pads also?

it could, but extremely unlikely. many people have tracked their cars in pouring rain and they dont get warped discs from it. chalk it up as bad luck, nothing you can do now and be glad they fixed it for free!

doubt you will get new pads, but you can ask.....