bayer-z28

iTrader: (14)

HELP!

This is what I've done.


Rebalanced wheels + tires 3X!!....was fine for a day then the VIB came back.
Re-adjusted PHB... was fine for a day then the VIB came back.
LCA RLB's.... was fine for a day then the VIB came back.
Readjusted Pinion angle w/ TA (-2*)....No differance. Angle was off one degree. (from lowering car)

It's not in the tranny, that was recently replaced, also w/ new clutch system. (CL and hyd system) Tranny was shot, did a clutch too.


I'm running out of options. I think I need to have my DS balanced now... if htta ant it.. I'm stumped. THe VIB isn't as bad as it used to be, but it's still there. Feels front end-ish. Slight shake in wheel.

mitchntx

iTrader: (14)

When did the vibration start? After the trans install?

SIC LSX

iTrader: (10)

drive shaft out of balance?

JD_AMG

do you have stock brake rotors?

ls1mightymouse

Whern does the vib happen? Idle? Driving low speeds? High speeds? Turns?

cocimitch

iTrader: (1)

Have you had a front end alignment? If the steering wheel shakes, it's either rotors or something in front suspension...

J. Brown

If the drive shaft was not re-installed the way it came out it could cause a vibration.

chino_man279

iTrader: (7)

Have the wheels/tires all been load balanced? Are the rims straight? Dont assume that they are, check them or get them checked. A bent rim is nearly impossible to get a perfect balance on.

Are all the bushings in good condition on the front end? Also check the rotors and slider pins for correct movement. Check for loose bolts anywhere in the front suspension. Get back to us.

Dragula

iTrader: (5)

What is your transmission output shaft angle. The DS should only be +- 2 degrees from that. My Tranny output shaft was 5 degrees down towards the rear. I had to adjust the pinion angle to +3 degrees. All my vibration issues went away. The -2 degree pinion angle isn't as critical on Torque Arm set ups as is it with leaf springs that change the pinion angle when loaded up during acceleration.

bayer-z28

iTrader: (14)

Ok... SOrry yall..

I lowered my car, the next day I installed my wheels. It started then. before the new trans.

My pinion angle is at -1*. It was 0 when I re-adjusted it after the lowering. Dragula, I see what you're saying, I'll recheck it when I change my oil.

I had my front end aligned after I dropped the car.

The vib happens at 60-70. At its worst at 65. Not as bad as it used to be, but it's still there.

DS or U-Joints are my next guess. I just don't understand how it would happen right after i installed my wheels. Who can do load balancing on the wheels? It's gotta be them.

mitchntx

iTrader: (14)

Hmmm ... reminds me of a story ...

Right after I bought my 2500HD, I bought a set of American Racing rims for it.

I had my original tires mounted up and there was a slight vibration at about 50mph. I went back NUMEROUS times for a rebalance.

Each and every time they balanced perfect. I witnessed the machine reading "---".

But I never could get rid of the vibration.

I bought new tires thinking I had a tread separating because the old tires were mounted wrong. Still a vibration at the same speed.

I again went back to the shop, we chucked up a wheel on the balancer and instead of balancing, we looked at true. Sure enough, there was a slight wobble. Only way we could detect it was to place the tip of a screw driver up to the lip of the rim and it would just touch the blade at one point and was 1/16" out in other places.

The hub appeared OK, but in several different places along the actual rim we kept getting the same indications in the same place.

I had the new tires mounted on the stock rims ... vibration gone.

Kudos to 4WheelParts for taking the rims back, without a hassle.

Can one of your friends loan you his wheels/tire package for a jaunt around town to see if the vibration goes away?

What you describe sounds like EXACTLY what I witnessed.

bayer-z28

iTrader: (14)

I still have my stockers at my buddys place. I was going to try it again. I'll have to contact the Discount Tire place in Las Cruces and see if they can exchange them.... D'OH!!

I talked to another guy on CZ28.com that had acouple bad experiences w/ American Racing. He went thru three sets before he got a good set.

Xsta Z 28

iTrader: (2)

Sounds like wheel - tire run out . . . meaning the wheel is not true like mitchntx said or the tire.

bayer-z28

iTrader: (14)

SOB... I've been in denial... ...

mitchntx

iTrader: (14)

So it was a rim issue?

trackbird

iTrader: (4)

I had a billet Centerline Galaxy wheel do the same thing. The center wasn't welded in it straight. The axle flange wasn't 90 degrees from the tire mounting flange, it was off and the wheel wobbled on the balancer. I lucked out and the tech caught it (saw it) on the balancer and let me know. When the new wheel came in, they even swapped it for free for me (Discount tire). It's not common, but it happens.

bayer-z28

iTrader: (14)

I'm almost convinced that it's a wheel issue. Latley it's been getting worse as speeds increase.... doing 75~ish, it messes w/ my voice.. like someone tapping on my back while I hum, -type thing...

SS1875

iTrader: (34)

I went through the same problem not to long ago, although your's does sound more like a wheel issue. I had the following done to my car.

1)Rebalanced all tires and checked for true.
2)Rebalanced driveshaft
3)Replaced Tranny Mount
4)Checked all Geometry of Rearend/TA
5)Tranny removed and Clutch rebalanced
6)Found out ASP Pulley was wobbling on Crank...replaced with ATI Damper

Frustrating and expensive to find a Vibration in these cars!!

trans-am nut

I had a vib at 65, I tightened the calipers down. and the vib went away, the back rim is bent a little so that could have caused it when it was on the front. mybe that titbit will help you guys