Jump to content
SAU Community

Recommended Posts

That's actually the cause of 99.9% of shudder. It's called DTV (disc thickness variation) and is caused by cheap pads, and/or excessive float in wheel bearings... which leads to the pad material being laid down unevenly.

GSL - i've had that before, and it was clearly visible as differently coloured areas on the rotor. Is it always visible?

My money would still be on rotors. Could have been glazed, but I would still say they are warped...

But also check your tyre pressures. Happened to me on the weekend, felt like something was very very wrong, like the wheels were about to fall off, steering wheel shaking violently, car wasn't handling properly... Checked the tyre pressures the next day, and they had dropped quite low. Pumped em up to 38psi and that fixed all the problems. I doubt you are experiencing the same thing because my problems weren't while I was braking, more while I was cornering. But worth a go anyway.

Will have to check that out, better safe than sorry :)

That's actually the cause of 99.9% of shudder. It's called DTV (disc thickness variation) and is caused by cheap pads, and/or excessive float in wheel bearings... which leads to the pad material being laid down unevenly.

It's VERY VERY rare that rotors actually warp. It simply doesn't happen, even on race cars. Even rally car that get them glowing hot then go through water spashes don't 'warp' rotors. It doesn't happen. It will be DTV. Machining them will fix the problem, but it often doesn't curing the underlying problem.

Commodores are really bad for shudder, and it's always excessive float in the bearings, which starts the problem, then the pad material being laid down unevenly on the rotor because it's not rotating square finishes it....

Some light reading by car engineer legend Carrol Smith:

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

I warped my standard rotors by getting the rotors hot and then sitting on the brake when I'm stationary, like at a traffic light?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Sorry I haven't been following all the detail, so you may have tried this. Does it idle with the tiniest bit of throttle you can add? You've mentioned the IACV, does it have an AAC valve and have you adjusted it at all (ie, screw the idle adjust screw all the way in, then back it out a couple of turns until idle is stable)?
    • My bad, I unplugged the one underlined in red instead of yellow before. With the car started, after unplugging the IACV (the one underlined in yellow), it idled at around 400/500 for 3 seconds before stalling. Attempting to start the car without the IACV will not start the car.   It does stutter and sputter for around 5 seconds before dying. However, immediately after starting it, you can already hear some slight sputters from the exhaust.   It won't start with the AFM unplugged. If it is when the car has already started, it stalls in a few seconds.   Yesterday, I did take some logs using Nistune of 3 scenarios. Car idling till it stalls Car idling and unplugging the IACV Car idling and removing the AFM I also have some previous logs of when the Car is idling till it stalls and when driving and it cuts. I am not really knowledgeable enough to understand what to look for. After every test, car idles rougher and rougher, until I have to stop. It will be fine the day after.
    • There is no difference between a 17x8 and an 18x8. The total diameter of the tyre needs to remain +/- the same (so you don't mess up the gearing, speedo reading, and clearance when turning front wheels..... so you just need to use a lower profile tyre on th 18 than you do on the 17. /rocket surgery.
    • I thought the same to start with. But then I thought it was one of those LCAs where the end of the ARB goes through a bushing in the LCA itself, instead of having an end link.
    • Yeah - I mean, go the other way. Smaller range. Not larger.
×
×
  • Create New...