R32 Gtr High Speed Vibration

[gtr315]

HI EVERYBODY.

HAVE OWNED MY GTR FOR ABOUT 2 YEARS NOW AND SINCE FIRST PICKED IT UP IT HAS A AREALLY BAD VIBRATION WHEN BRAKING FROM OVER 140KMH. I HAVE REPLACED UPPER CONTROL ARMS, CASTOR RODS, FRONT BRAKES WITH JUST JAP G4 KIT, WHEELS AND TYRES ETC. HAVE REPLACED FRONT DIFF ASSEMBLY WITH S/H UNIT-COMPLETE SUMP ASSEMBLY. U CAN FEEL IT THOUGH THE BRAKE PEDAL BUT MOSTLY THROUGH THE BODY OF THE CAR. HAS ANYONE ELSE HAS THIS PROBLEM BECAUSE IT IS REALLY STARTING TO GET TO ME. AT NORMAL SPEED BRAKING TURNING IT FEELS PERFECT.

CHEERS.

[Slim Mat]

When you fitted the Just Jap G4 kit, did it include the brake disks?

When disks get warped they will cause a shudder through the car under braking. It's probably not very bad since you can only notice it at high speeds.

[MrStabby]

I have the same problem. I replaced the rotors - no difference. My next step is to clean the rotor to hub mating surfaces to make sure they're both shiny metal. Some of the stuff i found on the web said that even a tiny bit crud on here will cause problems. I've done one side and it took 3 hours.... but i wanted to be sure it was perfect. Its worth a try.

[blind_elk]

How are you feeling the vibration? Through the steering wheel?

[gtr315]

Hi

The whole kit was done including the discs. Rear discs have been machined aswell. Not feeling vibration through steering wheel at all just throught the brake pedal slightly and mostly through the whole car. It really feels like the tailshaft is going to let go. When the disc were done all the hubs were cleaned beacause we had some troubles when they where fitted. It is to the point where at 160kmh when braking u really feel like u have to back of the brakes and let it coast. IT feels like a very solid vibration. All I can think of is that the front inner c/v joint are worn and when it loads up under braking at speed it vibrates. That is the only thing that I can see that would come through the whole under brakes.

Cheers

[blind_elk]

If it's coming back through the pedal, then it might be the ABS!

[Slim Mat]

Check the run out on the disks first

If the CV's are worn you should be able to rock the wheel back and forth with out the driveshaft rotating. However if it were the case that they were loading up as you put it, wouldn't it vibrate under acceleration aswell?

What sort of vibration is it? Back and forth pulse or sideways vibe? Shake?

Hold on to the gear stick when applying the brakes, if it shakes with the same rythum it could be rear brake related. Or if it's front you should feel it through the steering wheel.

If it were a driveshaft it would vibrate all the time, not just under braking and you probably wouldn't be able to get to 160.

I still think something in the brakes.

[gtr315]

Thanks for feedback.

It is more a sideways shake of the car. My rear discs were machined and new pads fitted about 6000kms ago. Vibration not changed at all. My front diif was replaced with s.h unit about 18 months ago because it was comletly stripped for some reason. I havent heard of many people that have had problems with the front diff. Could there be something in the front diff transfer case assembly that could cause this under brakes? Surely someone has had this same problem and found out a fix for it? PLEASE.