costas1 Posted March 30, 2012 Share Posted March 30, 2012 hi fellas..i removed the wheels today and noticed that my front brake discs are a bit loose.i could move them back and front.i am not talking beetween disc and bell looseness .the disc including the bell can move. the brakes are brembo gran turismo. is this normal? p.s for the last 6 months the steering wheel will shake massively when trying to brake at a speed of 60+. is this what causing it? Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 31, 2012 Share Posted March 31, 2012 Not sure about brembo brakes but stock discs just sit on the studs, they are not retained Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 31, 2012 Share Posted March 31, 2012 (edited) The bell can't move as its sandwiched between the hub and the wheel once the wheel is fitted and torqued up. Are yours fully floating as the Gran Turismo set i've just read about are so the disc will move on the bell. If they are then you need to take them off to check them. Edited March 31, 2012 by Dnk re read the op's post lol (see edit history) Quote Link to comment Share on other sites More sharing options...
jagman Posted March 31, 2012 Share Posted March 31, 2012 Your problem is the discs out of true -they need skimming on car , and make sure that mating surfaces are super clean . bolt the disc on with the wheel off - then spin the disc and measure between disc surface and caliper - you can use a simple matchstick just to see if the disc is true there are no retaining screws with the brembo set up ,the wheel bolts hold them in place. Assuming the bells are the correct supra fitment Quote Link to comment Share on other sites More sharing options...
costas1 Posted March 31, 2012 Author Share Posted March 31, 2012 the discs are not moving when the wheels are on.they are only moving when the wheels are off.yes the brembo set up is designed so that the bell moves a little between the bell and the disc.i was asking about movement between bell-disc and the car hub when the wheels are off. jagman..the last two garages i went they also told me that the discs needed skimming.so we took them off and took them to the lathe.since then the problem is getting worse.and the funny thing about that is that the discs were new when they told me that they need to be skinned. so now nobdy knows what is going on Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 31, 2012 Share Posted March 31, 2012 If they were new why not simply send them back ? did anyone actually check them properly and the bells ? Also just to rule it out does the steering shake only when you apply the brakes ? Quote Link to comment Share on other sites More sharing options...
costas1 Posted March 31, 2012 Author Share Posted March 31, 2012 the discs came new .i do not know if anybody ckecked them at the garage.(how do you check new discs?).and no i did not send them back because after installation they were used so i thought i can not send them back. yes the steering shakes massively only when i push the brakes and at speeds everything over 60 Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 31, 2012 Share Posted March 31, 2012 With a fully floating disc i'd remove the disc from the bell and check both parts seperately, could be done on a surface plate with a DTI or set up on a CNM machine or put on a lathe and checked with a DTI or on a milling machine etc etc. I'd simply use a micrometer first to check the disc was actually parallel on its thickness then carry out further test to see if it or the bell is warped or even been made out of true. Quote Link to comment Share on other sites More sharing options...
costas1 Posted March 31, 2012 Author Share Posted March 31, 2012 i think at the machinery garage the technician put the bell also on the lahte and did some work in the inner diameter of the bell.maybe he skinned some material and that's why is now loose from the car hub. i was thinking of putting metal rings to hold the bell tight on the car hub.(just like the ones we put on the aftermarket rims). would that be safe and correct to fix my problem.will i have any problems with the rings considering the heat is being generated in these spots? Quote Link to comment Share on other sites More sharing options...
jagman Posted March 31, 2012 Share Posted March 31, 2012 They have to be skimmed on car - and the hubs as clean as you can get before fitting the bells ,any dirt rust etc can throw them out , almost all judder problems are discs un parrallel ,barring the obvious caliper loose I have Brembo BBK and they needed a skim - to take up hub error ,only a couple of thou out and you get judder - skimmed on car now perfect -nice brakes by the way ,great progressive braking Quote Link to comment Share on other sites More sharing options...
costas1 Posted March 31, 2012 Author Share Posted March 31, 2012 so now what do i have to do? first check again the discs and the bells if they are wrapped.then clean the car hub .what about the disc-bell looseness?how about yours?is the disc-bell loose when you take off the wheel?can you move them front and back while the caliper is still on tightened? what about the rings idea? Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 31, 2012 Share Posted March 31, 2012 (edited) I have never skimmed a disc on the car in all my years in motorsport and engineering and have always ground discs on a cylindrical grinder and never had a problem. If theres a problem with the hub being out or buckled then i'd be fixing that rather than masking the problem. Edited April 1, 2012 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
costas1 Posted April 1, 2012 Author Share Posted April 1, 2012 ok mate.i will try fix the hub looseness and see what happens.thank you very much for your replies.i will let you know in a few days. Quote Link to comment Share on other sites More sharing options...
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