100Kph Shuddering Like Im Getting Continuously Rearended =O

[The Mothershup]

Guys, I just registered as Stagea info is few and far between on the net compared to Skyline. Forgive me if this issue has been raised in another thread, but I got to like page9 and thought

Here is my issue and it is a technical/mechanical one. Purchased my first Stagea, 4wd light was on solid. Began maintenance by topping up Attessa reservoir(righthand side of the boot). 4WD light went off. Driving specifically between 85-115kph, I would estimate, I have a shuddering or 'pulsing' sensation coming from what I believe to be the rear axle of the car. Like additional torque is being applied to the rear driveshafts momentarily in an on/off fashion. I would say that it is not a reducing speed sensation, as in abs acting on the rear wheels for some even more bizarre reason, especially as it only happens at a neutral or light load throttle position and the sensation is destinctly coming from the rear end. I have bled the attessa pump as per the instructions for a skyline except I couldnt find the plug to disconnect in teh drivers foot well like skylines are supposed to have. So we used a vacuum bleeder and me inside the car turning the ignition on and off to get pressure from the pump. Im will attempt to re-bleed tomorrow. We did loosen the nipple on the pump itself and had some drips to indicate no air but not entirely sure as it was the first time attempting to bleed an attessa system. Really hope someone can help. Any and all advice welcome

[scotty nm35]

Sounds like mismatched tyre sizes to me. Can you borrow a matched set to try or just rip the front prop shaft out for the time being?

[Mohsen]

could be your hicas playing up. my 34 did that... but it skidded and bounced all over the place

[Chris_Beli]

+1 for mismatched tyres, mine did that when I had two tyres the same size but different brands on the back so it is extremely sensitive, the pulsing is the attessa trying to correct for the wheels spinning at different speeds

Edited May 24, 2012 by Chris_Beli

[KiwiRS4T]

The pump can be switched by undoing the plug which is to be found behind the drivers kick panel. It is a small plug in my case taped to another loom. However turning the engine on and off probably works just as well for your puposes. Tyre sizes are critical. In NZ it is anyway illegal to have different tyres on the same axle.

[The Mothershup]

Hey, no tires are all the same all round. Nissans usually use an equal width tire allround by design. Im going to try the on-off ignition method again tomorrow for longer. Going to look for a drivetrain expert in my area who may have a gem of wisdom about this.

[wolverine]

Same tyres but different rolling diameter will do this.

[bjd]

I have recently had a similar issue after putting a new wheel and tyre package on 19"s all round turns out the front tyres are the issue. My problem was mostly vibration in the steering wheel at around 90 - 120km. Cheap ass china tyres... Will be getting some Federal tyres on Monday.

[Jezboosted]

Hey, no tires are all the same all round. Nissans usually use an equal width tire allround by design. Im going to try the on-off ignition method again tomorrow for longer. Going to look for a drivetrain expert in my area who may have a gem of wisdom about this.

Are all tire pressures equal ? All worn the same depth ?

Did any wheels lose any weights ?

Do you have a torque split gauge ? What does it do during 85-115km/h ?

Any crap on the wheel speed sensors ?

How low was the fluid before topping up ?

[99 rs4]

I have this same problem. Im pretty sure its the tyres too. I just put newies on the front and kept old no name shit on the rear to wear out. My left is more worn (i like to stick the ass out on the left ) and yer the shuddering is really starting to piss me off. I will get new tyres and see if it fixes it and let you know?

[bjd]

Just got a set of Federal RPM 225/35r19 and Its like I just got a new car. Very happy and at only $195 a tyre I'm left with change compared to any other good alternatives. It was deffinatley the tyres in my case.

[Down_Shift]

Can anyone confirm that it's the tyres?

Cause i just started having this problem since Sunday and it's driving me nuts!

Attessa reserivoir is full, got all exactly same tyres. I've changed nothing to the car and it suddenly started doing it....

I noticed that my speed seem to drop a bit faster than usual when I'm just coasting in gear at higher speeds, and recently sometimes i can smell something burning after turning off the car...

[scotty nm35]

Drop in and borrow a set of wheels if you like, it is most probably the tyres but it could be the wheel bearing, or the brakes grabbing...

[Down_Shift]

If you have a spare set of wheels for me to try it out that would be great!

Won't have time until early next week though. :-/

But it doesn't make sense if it's the tyres, since they were perfectly fine...

[Down_Shift]

Okay, i just found out that my right rear brakes is grabbing..... excess heat only from that wheel..

[scotty nm35]

I have a spare here if you need it, but I repaired mine by straitening the slider pin, it worked fine after that and some new grease.

[wolverine]

Edited

Edited June 28, 2012 by wolverine

[Down_Shift]

All good, I rushed to the mechanic the next morning.

While on the hoist, the wheel couldn't barely be moved only just wiggle a bit.

Disassembled the brakes and it decided to work fine again.... but there's still a very slight hesitation on the wheels.