[Short-Throw]

Hello all,

There have been V2 owners concerned on how to remedy an observed wheel clicking.

A few responded that removing the front wheels and reinstalling is a fix. This terse action will only serve as a temporary condition.

Please review the procedure below for a more robust solution. This info will immediately help efforts of both owners and dealer service.

I will post the official TSB once it is approved for release.


Vehicle: MY2009 CTSV

Condition:
A clicking noise has been noted emanating from the front wheels. Condition is noticed at low speeds (walking speed) during full wheel lock turns.
(Full lock parking lot maneuver).
Clicking noise is generally noted as approximately 1-4 “clicks” per wheel revolution.

Cause:
Interaction between wheel mounting face and wheel mounting surface on rotor.

Correction:
It is recommended the procedure below be completed on both front wheels.
It is not necessary to clean rear wheels for the “clicking” condition.

Procedure:
Remove wheel
Clean wheel as follows:
•Use clean cloth dampened with GM Brake Parts Cleaner 12378392 or equivalent.
•Wipe the mounting surface of the wheel to remove and residual grey or black material that has accumulated on the wheel mounting surface.
Clean rotor as follows:
•Use clean cloth dampened with GM Brake Parts Cleaner 12378392 or equivalent.
•Clean the wheel mounting surface of the rotor to remove and residual grey or black material that has accumulated on the wheel mounting surface.
•During cleaning process be sure to clean the rotor near the wheel pilot at the center of the rotor.

Reinstall wheels. The wheel nuts should be tightened to a service torque of 215Nm (158 lb/ft).

Note the increase wheel nut torque (190Nm to 215Nm) - (for forged CTSV wheels only).


You will recall the 2004-2007 V's wheel is a six bolt pattern. The V2's 5 bolt pattern was accomplished by using truck size lugs (forged wheels), hence the higher torque level required. A great piece of data for those of us that like to work on our cars personally. Cast wheels and steel wheels should be torqued to lower spec.


OFF TOPIC: The track opens tomorrow! :lildevil:




Mike

 

[NormV]

Wonder what the original trq spec was? Never seen a passenger car with that high of trq. Most European cars are around 90.

Norm

 

[Short-Throw]

Wonder what the original trq spec was? Never seen a passenger car with that high of trq. Most European cars are around 90.

Norm

2009 Old spec 190 Nm (140 lb/ft)
2009 New spec 215 Nm (158 lb/ft)
2007 Spec 140 Nm (100 lb/ft)

 

[jvp]

2009 Old spec 190 Nm (140 lb/ft)
2009 New spec 215 Nm (158 lb/ft)
2007 Spec 140 Nm (100 lb/ft)

That's an insane amount of torque. Good to know.

jas

 

[Short-Throw]

Never seen a passenger car with that high of trq. Most European cars are around 90.

Norm

Corvettes are set to 100 lb/ft.

 

[Short-Throw]

That's an insane amount of torque. Good to know.

jas

Yes,

I usually had to adjust my torque wrench for a higher setting on my dually. I never thought it would be the other way around.


Mike

 

[readyact]

Short-Throw thanks for the info.

 

[NormV]

I think all of GM is 100 lb/ft. Not sure about Saab. I've seen people go a tad over 100 on GM cars and the studs break. Should be a cheap recall for GM until someones wheels falls off.


Norm

Corvettes are set to 100 lb/ft.

 

[neuronbob]

I haven't had the clicking, but now i know what to do if I do. Thanks!

 

[proexpert]

OFF TOPIC: The track opens tomorrow!

Let us know how the V2 does on it's first day.

 

[poor-sha]

I'm not clear what "Interaction between wheel mounting face and wheel mounting surface on rotor" means. Is the wheel coming loose and wobbling or is a little dirt causing the problem? If it's just a little dirt I'm going to have a problem with this car.

 

[jvp]

I'm not clear what "Interaction between wheel mounting face and wheel mounting surface on rotor" means. Is the wheel coming loose and wobbling or is a little dirt causing the problem? If it's just a little dirt I'm going to have a problem with this car.

My bet is the following (Mike will be sure to clarify) -

- The cleaning procedure isn't required, just something that you should do while you have the wheels off. Yeah. Um. OK. Skip that step.

- The torque is the real issue. There's probably a hair too much play in the rotor, and when you turn the wheel and heave the suspension sideways at slow speeds, you hear the rotor "clunking" as it slides around on the studs and taps the inside of the wheel face. Likewise the wheel can slide on the studs.

- Tightening the lug nuts down to 158ft-lbs is GM's response to this issue. Extra ft-lbs means extra compression against the brake rotor, which means no sliding around.

That's just my guess based on what Mike wrote.

jas

 

[Short-Throw]

I'm not clear what "Interaction between wheel mounting face and wheel mounting surface on rotor" means. Is the wheel coming loose and wobbling or is a little dirt causing the problem? If it's just a little dirt I'm going to have a problem with this car.

No worries Sean, read below! :thumbsup:

My bet is the following (Mike will be sure to clarify) -

- The cleaning procedure isn't required, just something that you should do while you have the wheels off. Yeah. Um. OK. Skip that step.

- The torque is the real issue. There's probably a hair too much play in the rotor, and when you turn the wheel and heave the suspension sideways at slow speeds, you hear the rotor "clunking" as it slides around on the studs and taps the inside of the wheel face. Likewise the wheel can slide on the studs.

- Tightening the lug nuts down to 158ft-lbs is GM's response to this issue. Extra ft-lbs means extra compression against the brake rotor, which means no sliding around.

That's just my guess based on what Mike wrote.

jas

You don't really believe the car would have been released if such conditions were true. Understandably a guess, but simply not true. :tisk: I only mentioned the tq spec to give people a heads up that these are special lugs, not because anything was loose.

Sean, Jason and all,

The Internet has spoiled us with so much information that there is more erroneous than correct data out there.

Why cleaning the rotors is required...Do Not Skip This Step.

Cleaning the wheels is required because issue stems from coating on the rotors (to reduce corrosion) at interface (between the wheel and the rotor)tends to 'rub off' with the microscopic movement between wheel and rotor. The coating residue acts as a lubricant in the joint and allows more relative motion between components - still microscopic, but enough to result in 'clicking'.

If you do not clean the wheels, you are not removing the 'lubricant' between surfaces. I'm sure many of you have picked up a new rotor and experienced your fingers feeling greasy afterwards even though there was nothing apparently on them.

By increasing torque, the clamp load raises, which in turn reduces the tendency of any movement at the interface.

Furthermore:

It is not from a little dirt (from external sources). You're okay here Sean!

It is not from any wheel coming loose.

It is not from the rotor or wheel moving and hitting wheel studs.

It is not from insufficient clamp load.

It IS from minute movement between wheel mounting surface and brake rotor surface at the interface.

I wouldn't get too worried about this as there are cars that will never exhibit such a noise. If so, it's an easy fix with NO MATERIAL effect.



I hope this added clarity.


Mike

 

[jwa999]

So, it sounds like it's not something we mortals have to worry about too much?
I hear it all the time on sharp turns, specially when I use this hollow alley across the street to turn the car around.
I have bigger problems in my life than a few innocent noises coming from my car, even if it's brand new, as long as it's not a bearing getting overstressed....

 

[mbshoe]

This was timely. Both Monday and Tuesday as I backed out of my parking spot with the window down, I heard this clicking from the front left wheel. Didn't happen going forward, but then I had straightened the wheel out already.

Thanks for the information.

Mike

 

[LV_V]

Should've stuck with 6 lugs

 

[UAEmonster]

I have the same problem with the clicking thing , so i should be worried about it or not ?!? since the car is new , it worries me of what the... is that !!!?

or shall i take it to the dealer's workshop ?!

 

[Short-Throw]

So, it sounds like it's not something we mortals have to worry about too much?

Correct. No worries at all.

or shall i take it to the dealer's workshop ?!

This is just a simple matter of cleaning a few parts. You can easily do it yourself or take the car to service. It's a very easy quick fix, and again, it's nothing to worry about.



Mike

 

[Fubar75207]

Thank you for posting the issue and solution :thumbsup:

 

[Short-Throw]

This was timely. Both Monday and Tuesday as I backed out of my parking spot with the window down, I heard this clicking from the front left wheel. Didn't happen going forward, but then I had straightened the wheel out already.

Thanks for the information.

Mike

:thumbsup:

I have over 4K miles on mine and not a peep.