Wicked Weasel

So after VIR this year I got a vibration when I apply the brakes. I thought maybe a warpped rotor so I replaced pads and rotors. I went out again and still had the vibration, but I also now had vibration in turns. That turned out to be the hub so I replaced that. I also replaced the front pads thinking that the hub might have caused uneven pad wear.

So now the vibration in the turns is gone, but now on medium braking the vibration is still there. On hard braking I can get the vibration to be almost nothing. I really am running out of thoughts and wondered what you guys think. Maybe the rotor is warpped after the hub being bad? Maybe I need to buy 18inch wheels and go wtih 14in stoptech over my 13 inch Wilwood setup

I am just frustrated because the car at VIR had no problems until the last 2 laps and since then I cannot get rid of the vibration.

thanks

Bob

02impactblue

If your running 2 piece rotors your center hat could be the culprit. Get a dial indicator and check for run out on the rotor assembly.

Umrswimr

Did you replace both bearings or just one?

davidfarmer

usual suspects are play in tie rod ends, play in bearings, or LOOSE bearings.

Can you feel it in the steering (front vibration), or do you feel it in the entire car (possibly rear, or drivetrain). If you can link it to ANYTHING (ie right vs left, front vs rear, rpm dependent vs speed dependent) we can help find it.

Wicked Weasel

It is coming from the front and it feels more dominant on the left side.

I replaced both left and right side hubs, but did not replace the bearings or tie rod ends.

The reason I replaced the driver's side hub is because when I pulled on the tire when it was in the air I was getting movement (in and out). After I replaced the hub there was no movement.

I thought this was the problem and as I somewhat stated above after the replacement of the hub the car tracked fine under acceleration where before I was getting some vibration as the speeds increased.

So I was extremely happy that the acceleration vibration was gone, but then I when I hit the brakes the decel vibration was still there not making me a happy camper.

As I also noted the vibration is the worse when I am medium on the brakes. If I brake late and hard the vibration is almost not there. Maybe this is my cars way of saying use your brakes less

I probably should have swapped out the bearings when I did the hubs

Cobra4B

My last trip out at VIR I had some bad vibration when braking... I thought it was simply the pads/rotors being worn oddly.

David how do you actually check for tie rod and hub play? I have VB&P HD tie rod ends... I'd doubt those have worn out as they're all metal.

The front hubs are fresh from early '06 w/ 4 or 5 events on them... rear hubs were replaced this summer.

Cobra4B

The hub/bearing is one assembly... you did replace them.

ZR1 MK

Bob
My check would be:
1-Tire spun on wheel (I mark mine, worst spin was approx 4 inch before my dry mounting)
2-Balance weight falling off (I mark mine, glue or tape them too but lost one once)
3-Make sure clean surface between wheel/rotor hat and rotor hat/hub.
4-Hub run-out (although my worst worn hub never created a vib)
5-Rotor run-out


You mentioned bearing replacement. What bearing?

Cobra4B

^ Again... on the C5 the hub/bearing are one unit.

John Shiels

When you are braking real hard there is more load on what is vibrating so you are not feeling it would be my theory.

Wicked Weasel

Correct - I meant that I did not replace the Ball Joints.


thanks

John Shiels

should be real easy to see play in the ball joints.

Cobra4B

^ How... I want to check over my front suspension?

Wicked Weasel

John when I took apart the hub I also had the ball joints apart (part of doing the work). They seemed to be ok. When I put them back together the fit was fine.

I think tie rod ends and 2 piece rotors is where I am going to look now.

Richy1

Bob, I having the a very familiar problem. It's driving me crazy I feel vibration from the left front when making right turns (not 90 degree, highway turns). I don't get the vibration when braking only when I put a load on the front left, usually around 40 mph and up.

I curious to see what your out come is on this.

Richy

Wicked Weasel

well slowly I will pull every piece of suspension and brake part off until I find the cause. At open track day at WGI Friday I was getting close then I had a mechanical issue with the engine and that ended that.

John Shiels

tie rod end should be able to spot easy if it was bad. Can't see it making vibration if was not real bad. Swap tires and rims to see if it made a difference? What happen with motor? I am going Monday for open track wonder if I will survive after not running all year

You could have two problems at once and solved one with the hub.

Wicked Weasel

Yeah I have charge wheels and tires. Even rebalanced - all the typical stuff.

Hub was a good find so I am wondering if that caliper is screwed because of the bad hub.

what happened?? 50+ 1/4 mile passes and 3+ years of road racing happened

Cobra4B

^ Yeah but your motor is modded.... was it:

1. Valve spring
2. Timing chain
3. Thrown rod from rod bolt going?
4. Other?

Wicked Weasel

We are still looking into it. I was going around turn 7 at WGI and heard a small pop and then the car went dead. No oil - no other signs of damage.

I had it on the trailer and saw fluid on the driver side and though it was a rod, but the fluid turned out to be power steering fluid because the rack and pump went. The only cooler the car didnt have was one for the power steering

Anyway I dropped it off at the shop Tuesday and really we just took a quick look at it. No holes or anything else dripping. I figured I had a 402 built for me last year because I thought the engine would not last another year so this would be a good time to put it in and to make other changes.

WGI was my last track day of this season. I got in 17 track days this year.