Vibration when braking need some help!
 

Hey guys, I recently (5 days ago) lowered my car on Swift springs and installed H & R 15mm spacers... I havent messed with the alignment yet. I noticed yesterday while driving the car on the highway at about 90 mph I pressed the brakes to slow down and my steering wheel started shaking. I checked the lug nuts when I got home and at least by hand they feel tight enough. However I noticed the 2 rear wheel locks are loose and broken (meaning I could see the stud)
Any Idea as to what the hell is happening here... My first thought is someone tried to steal the wheels but my car sleeps in my garage and I dont take it anywhere but to work on a secure lot.

Sounds like incorrect wheel locks that were put on. Broke due to incorrect application. Where you get the locks? Are you still on oem wheel? Check this out http://www.the370z.com/images/servic.../NTB09-024.pdf

I had a similar problem recently, but mine was a slight vibration/steering wheel shake above about 45 MPH. Turned out that there was some mud in the pad groove that had caused uneven wear of the rotor.
In your case, the first thing I'd check is lug nuts. Checking by hand is worthless unless they are about to fall off. A bad rotor would be my next suspect. And then spacer alignment.

Ok, I checked the lug nuts and they needed some adjustment. I torqued all if them and changed the 2 locks for new ones(OEM). I drove it on the highway... Took it to 110 and still the same problem... I guess I need to check the spacers then


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bump!!

Is it only when braking?

If this only happens when braking then warped rotors.

I agree! If its constant then the spacers are not flush on the hubs....thats my opinion.

:iagree:

If it's when braking, it's warped rotors.

Mods, please close

LOL.. Its only when braking but the car only has 6700 miles. Can the rotors be warped already?

It's possible. Not usually so soon, but all your symptoms indicate a "warped" rotor. If it's bad enough, you'll be able to eyeball it. Pull the wheel, remove caliper, remove rotor and inspect. Look for areas where the face of the rotor is is rougher and/or has a different "sheen". When we pulled my rotor a few weeks ago, the difference was very obvious.

Yes, my mom can warp rotors in fúcking 50 miles, lol

Oh, hey, OP, the rotors are covered under warranty, TECHNICALLY, somehow they are considered a non consumeable item on the car, never knew that

So go to the dealershít and get a new set of rotors

Thanks guys.. I'll check that out


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You could also be getting a brake pad deposit on the rotors. It feels like a warpped rotor from when it happens. From what I have been reading on here. The stock pads are noted for doing this. ;)

Thanks again guys... I called Nissan and even though I rather not bring the car there I didn't wanna pay for new rotors already... Anyway found out I have to pay because brakes are only covered for the first year! I will check the rotors and be 100% sure.


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you can take them of and go get them turned if you didn't glaze the rotors. You mostlikely got this horrible task accomplished by doing some significant braking and then parking it soon after. If you drive around and you start to really get those brakes heated up, you should try to find a way to drive your car without hitting your brakes for approximatly 5-10 min so that they have a chance to cool down. Try downshifting some more.

Thanks Rusty... Love your build thread btw... cant wait to see more.

43k on stock pads and rotors.....no problems with vibrations here. Like i stated before in previous post, If you are braking hard and parking it immediately then you are effectively attempting to warp your rotor. I did hard braking from over 130 in my Z last thanksgiving week but drove 15-20 min solid without using my brakes and have yet to have any glaze,warp, or vibration issues. Stock pads and stock rotors.

That's good, but he's right. Any OEM brake pad formula (Highest-end cars aside) has a propensity for this because they're pretty much universally 'Material Transfer' pads.

The only cars I've owned that this has happened have been ATX cars where you HAVE to apply brake force much more often than in an MTX.

The worst part is, it can be hidden from you in a used car by having the rotors turned. As soon as you wear them in a little it'll come right back, because it causes a chemical change in the rotor material that goes deeper than the surface. You have to take of a couple tenths of the entire rotor surface to get below it (which may result in taking off several tenths on the high spots), which almost never happens. They just even it up and call it a day.