> 80 km/hr shudder. Also, rear fascia question.

[jazza15]

After oversteering and mounting a kerb in the wet, my VT suffered a buckled wheel and a shudder at 80km/hr or faster. I wasn't the one driving by the way!
So the buckle was fixed and wheels all balanced professionally.The tie rod end replaced and therefore a wheel alighnment was done.
What could be causing the shudder? Steering box seems to be the biggest possibility as it is leaking out of the rack boot on the opposing side to where the impact with the kerb occured. The oil filled control arm bush?
Some knowledgable and logical advice/solutions would be greatly appreciated.

On a lighter note. Does the centre console rear fascia just pop out? Is it held in with those same clips that hold in the front dash fascia? Any unscrewing required? Do i have to take out the whole bloody centre console? that's what I'm getting at as i just want to paint my dash

[Tsunamix]

Possibly Brake disc warp. At least thats easy to fix. Your wheel may still be slightly buckled and not tracking truly. An easy check is to fit the spare.

If the shudder remains, its probably disc. For it to be a shudder, it has to be something that rotates.... Or something not fixed properley like a rose bush floating in the breeze its that loose. But that would clunk at low speed as well.

[jazza15]

Well that's what the mechanics at Goodyear said, but I didn't believe them, because if the brake disc was warped, then i would get a braking shudder wouldn't I? They also didn't balance my wheels properly, which is why I took it to K - Mart tyre and auto service, where they also aligned my wheels $10 cheaper.
Also, a warped disc couldn't possibly occur from hitting a kerb could it? it just doesn't make sense

[adamc11]

Warped rotors only cause shudder when you brake, not when you cruising with foot off the brake.

[Tsunamix]

I disagree, though normally I wouldn't.

Normally warped discs an be felt as a pulsing in the brake pedal. In this forum on a couple of other threads though, people have mentioned the exact same symptoms, that have only been cured by rotor replacement. I have also had 2 mechanics tell me that VT rotors are of quite a soft material. perhaps too soft.

After going through the same things as you, and balancing my wheels, i still have a shudder that starts at about 120KMH through the steering, but it can also be felt through the suspension.

I have ended up thinking that the VT is a freak car that behaves differently to the norm. That being said - I should get my car back next week, and i have a new set of rotors to bolt on. If my shudder goes away, ill post it up.

Search on my name to see some other threads about this.

Cheers

[WhiteOx]

I disagree, though normally I wouldn't.

Normally warped discs an be felt as a pulsing in the brake pedal.

Shudder felt through steering wheel = Front Rotors.
Shudder felt through brake pedal = Rear Rotors.

[Tsunamix]

Thank you

[jazza15]

Thanks guys, that really helped.
I was told that my front discs were warped by goodyear, however they were sketchy as with the details and initially told me to "just drive it (my car)" when i asked what i should do about all the "possible" damage that could have occured from the accident. With this sketchy as description, i got 1 buckled wheel repaired and replaced a tie rod end from the advice of a soon-to-be apprentice mechanic/ good friend gave me.
I took it to K-Mart tyre and Auto service, where they were able to align my wheels again ($10 cheaper) and balance all of my wheels properly as goodyear had failed to do this.
I had purchased a pair of rotors from the wreckers, but returned them when i changed my mind after my friends advice.
I will do some testing to see if there is anything (noisewise or vibration wise) when i brake, tomorrow. Will also paint my dash and LED convert my heater controls.
It looks like replacing the front rotors could be the way to go as "vt's are (may be) weird".
Will keep you posted on my progress.

Shudder felt through steering wheel = Front Rotors.
Shudder felt through brake pedal = Rear Rotors.

I like your theory. Let's hope it is correct for VT's.

[BlackVXGTS]

Another rule of thumb:

Vibration < 80kph - problem at front of car (wheel balance etc.)
Vibration > 80kph - problem at rear of car

[jazza15]

That sort of contradicts what everyone else has been saying, but it is a valid point, thanks.

[garywg]

Sorry White Ox, but nearly all of the shuddering in vt & vx's is front rotors,although how they would warp from hitting the gutter is a mystery.

[jazza15]

Bit of an update. Really tested out my brakes today and nothing out of the ordinary. The shake is still there in the steering wheel. I reckon it is at its worst at 80km/hr, then gets shorter and faster (the shake of the steering wheel) towards 100km/hr. Haven't taken it much higher than the victorian speed limit to test to see if it disappears at high speeds. There are hints of the shake as i go a little above 60km/hr.
How is tsunamix goin with his?

[WhiteOx]

Sorry White Ox, but nearly all of the shuddering in vt & vx's is front rotors,although how they would warp from hitting the gutter is a mystery.

I wasn't talking about any car in particular what I posted is a general rule of thumb.

Jazza15s problems are most likely to be caused by hitting the gutter and have nothing to do with his brakes anyway .... impact has probably bent/broken something.

[feg]

As the OP was not driving the car at the time it mounted the gutter who is to say that, that is the only thing that happened. In my experience you never really get the whole truth on what exactely happend prior to or after the incident. Maybe the person driving slammed the brakes on after the car lost control. The oversteer part sort of makes me question if there is enough weight at the front of the car to cause damage to the rotors by slamming on the brakes though.

[jazza15]

I was in the car when it happened, it wasn't a good feeling watching it unfold and not being able to do anything. I think we can just about give up on the warped brake rotors theory, at least until tsunamix comes back to me on how his similar problem went.
What else could be causuing my steering wheel to shake side to side as mentioned earlier?

[Tree cutter]

Was the bent rim repaired or replaced? Jack the front of your car up so the tyres are just off the ground and then turn the wheels by hand so you can see if there is any flat spots on the tyres or if the rim has any sideways movement. Sit a brick or something alongside the tyre as you are turning the wheel around and see if the distance between the brick and the tyre change at any point.

[Zeussy]

how about the wheel bearing unit??? there pretty weak and expensive to replace,

[jazza15]

Zeussy, they make a noise and vibration when they go. Surprisingly, there was no hub damage from impact with the kerb. Fronts commonly, eventually go on commodores, rears are more resiliant...unless you slide into a kerb.

I jacked up the car today (and put it on stands) and spun both front wheels. They seem to be buckled slightly. One wheel demonstrates a 'jolt' at one point of the rotation while the other one just seems buckled. Now, this is what Goodyear told me that "all wheels were buckled" when i asked them to elaborate on that, they were very sketchy and failed to tell me how this would affect regular driving. K-Mart tyre and auto service on the other hand said that my wheels (after already recently visiting Goodyear) were out of balance and were now fine. Upon hearing this i was delighted.
So it is now a case of finding a pair of perfectly good wheels to put on the front and determine whether or not this is in fact the cause of the shudder at 80 k's...and also finding a decent tyre place next time i need my wheels balanced.

I also did my first oil change today. I used oil flush which set me back about $20. My car nut friend recomended it to me and he even commented on how much it cleaned the rockers (and pressumably the rest of the engine) when he saw the result.
I also replaced my spark plugs and upon doing so, 2 leads broke. this tells me that they are all due to be replaced, which i will be doing very soon. Would you agree?...

[Tsunamix]

Im back in town. my VT is back from the shop with a new S-Pack nose. Tomorrow Ill take the time to bolt the rotors and pads on all round and we will see what the result is.

At least if this doesn't fix it, it can only be a prop shaft bearing.

cheers

[Tsunamix]

Ok heres the pics. Its a '99 VT acclaim in Bermuda blue mica with an s-pack nose. Im not sure whether to body color the trim strips or black them out as blue and black looks pretty damn scmick.

The wheels are CSA Gladiators in machined finish, although I think I would like to go chrome.

I guess you can see why I want to find a subtle boot lip or bob tail spoiler. The lines are pretty euro smooth to start with.

Previously I had a custom grille - opened up and blacked out, with metallic light blue+chrome mesh fill. looked quite aggressive.

I am tempted to paint the brake calipers red, and use a red mesh in the grille this time for a hint of aggression..

Todays plans - The set of slotted rotors go on, and a whiteline strut brace. New police spec pads as well. I'll upload some more photos as well.

[Thomo]

I dont know if this will help you but when i slid & hit the gutter in my VL turbo it warped the rim,brake rotor & axle in the rear. Only hit it at about 40kls.Had to replace it all.I would change your rim 1st & check to see if the rotor is warped.Dont need to hit them hard when they are hot.

[Tsunamix]

Current performance mods - POd filter - building a custom low mount intake that encloses the pod filter. 1.98 ratio rockers from MACE. Full 2.5" Sports exhaust, including 3 - 1 extractors, walker 2.5" turbo muffler, factory cat and walker resonator.

Future plans :- January

Gearbox. Full rebuild for the 4l60E including a stage 2 shift kit and a corvette billet servo.

February :-

Cold air intake. This is a custom low mount which accepts a pod filter which is fully enclosed and replaceable - inlets will be behind the vent in the s-pack grille.

March :-

Custom bermuda blue mica with special fx fascia for the dash and cosole. Upgrade to 3: full elngth, 3" metal cat, 3" walker turbo and reso.

April :-

Move house. Ugh.

May - None - see June.

June - Raptor supercharger + intercooler @ 10 PSI.

July - see June

August

Custom tune, 70mm throttlebody, under plenum insulator / spacer. NO top spacer - plenum to remain original volume.

September

3.7:1 ratio diff gears.

[jazza15]

Shouldn't this be posted in the 'my ride section'?
Thomo, yeah your spot on with that. I spun out and hit a kerb earlier this year and had to replace my front and rear hubs on one side (rear - whole trailing arm) and 2 wheels were buckled. I didn't pick that up til later, so the buckled wheels stuffed my hubs up again!
I have had a look at the front wheels spinning as mentioned earlier and i think that they are bucled as they have been balanced my two different tyre places, the second of which didn't believe that any of my wheels were buckled. I will check my rears soon, one of which should be perfect as i have already had it repaired.
From this, it could be said that the bucled wheels alone could be causing the 80 km/h shudder. to determine this, i might need to get ahold of some good wheels to determine this, or just get them fixed. Will keep ya's posted.

[Tsunamix]

OK. The rotors are on, (slotted), the police spec pads are in. front and rear was done. Rough bedding in is done and the shudder seems gone. i say seems because I havent spent substantial time at 120kmh looking for it, but short runs to 150 show no evidence of a shudder, when cruising accelerating or braking.

Cheers folks

[jazza15]

Well that settles it. If for some reason it isn't buckled wheels, then it could be a warped rotor, but I'm fairly sure its the wheels.
Steering box just doesn't seem right...