slowstang

iTrader: (3)

My car is an 08 ss/tc. Upon normal daily driving acceleration I get a loud audible click from what sounds like the axles. It doesn't happen all the time it's just every once in awhile. It only happens when torque is applied with the throttle. If I stop and take off again the car will do the click in either 1st or 2nd gear. The dealership said the noise is "normal" but it's getting annoying to me.

The best way to describe the noise is it sounds like someone snapping their finger really loud. Is it the retaining nut, axle, cv joint or something else that's making this noise?

ecot3c inside

iTrader: (11)

mine does this when I shift to 2nd at about 4500rpm. sounds like a shock recoil or something like you have a gas shock attached to your engine or some **** like that. I know what you are talking about though.

interested in the answer too.

damien

iTrader: (3)

Haven't heard of this on LNF axles before, but the LSJ's have definately had it. Mine's done it since day 1. The only fix i've heard was new aftermarket axles.

jb09ss

It's probably the retaining nut that needs to be re-torqued. Mine had that clicking sound last year and it was the nut.

ecotecturbo

It is normal.

rivaladore

iTrader: (7)

mine makes this noise to, glad to know it's normal

MaxVQ35DE

mine did this before my clutchjob, no longer does it. Must have been the axles

Cefaln452

iTrader: (5)

thank gm for shitty built and designed parts

jsbh2005

I have this same issue, however this happens on all gears. I noticed that if i do a no lift shift it does not make the noise as loud.

Dealership is looking at it on Monday since I have had it in 3 times now on this issue. they just keep telling me it is NORMAL. A clunk noise when shifting is not normal. Will update Monday night.

Malaclypse

iTrader: (1)

Have fun arguing with them. There's nothing they can do about it.

#03-07-29-004F: Manual Transmission Operating Characteristics - (Jul 29, 2009)


Subject: Manual Transmission Operating Characteristics


Models: 2010 and Prior Passenger Cars and Light Duty Trucks (Including Saturn)

2009 and Prior Chevrolet and GMC Medium Duty Trucks

2006-2010 HUMMER H3

with Manual Transmission




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This bulletin is being revised to add the 2010 model year and remove Isuzu from the models. Please discard Corporate Bulletin Number 03-07-29-004E (Section 07 -- Transmission/Transaxle).


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Important: Even though this bulletin attempts to cover operating characteristics of manual transmissions, it cannot be all inclusive. Be sure to compare any questionable concerns to a similar vehicle and if possible, with similar mileage. Even though many of the conditions are described as characteristics and may not be durability issues, GM may attempt to improve specific issues for customer satisfaction.

The purpose of this bulletin is to assist in identifying characteristics of manual transmissions that repair attempts will not change. The following are explanations and examples of conditions that will generally occur in all manual transmissions. All noises will vary between transmissions due to build variation, type of transmission (usually the more heavy duty, the more noise), type of flywheel and clutch, level of insulation, etc.

Basic Information
Many transmission noises are created by the firing pulses of the engine. Each firing pulse creates a sudden change in angular acceleration at the crankshaft. These changes in speed can be reduced with clutch damper springs and dual mass flywheels. However, some speed variation will make it through to the transmission. This can create noise as the various gears will accel and decel against each other because of required clearances.

Gear Rattle
Rattling or grinding (not to be confused with a missed shift type of grinding, also described as a combustion knock type of noise) type noises usually occur while operating the engine at low RPMs (lugging the engine). This can occur while accelerating from a stop (for example, a Corvette) or while operating at low RPMs while under a load (for example, Kodiak in a lower gear and at low engine speed). Vehicles equipped with a dual-mass flywheel (for example, a 3500 HD Sierra with the 6-speed manual and DuramaxŽ) will have reduced noise levels as compared to vehicles without (for example, a 4500 Kodiak with the 6-speed manual and DuramaxŽ). However, dual-mass flywheels do not eliminate all noise.

Neutral Rattle
There are often concerns of rattle while idling in neutral with the clutch engaged. This is related to the changes in angular acceleration described earlier. This is a light rattle, and once again, vehicles with dual mass flywheels will have reduced noise. If the engine is shut off while idling in neutral with the clutch engaged, the sudden stop of the engine will create a rapid change in angular acceleration that even dual mass flywheels cannot compensate. Because of the mass of all the components, this will create a noise. This type of noise should not be heard if the clutch is released (pedal pushed to the floor).

Backlash
Backlash noise is created when changing engine or driveline loading. This can occur when accelerating from a stop, coming to a stop, or applying and releasing the throttle (loading and unloading the driveline). This will vary based on vehicle type, build variations, driver input, vehicle loading, etc. and is created from the necessary clearance between all of the mating gears in the transmission, axle(s) and transfer case (if equipped).

Shift Effort
Shift effort will vary among different style transmissions and synchronizer designs. Usually the more heavy duty the transmission, the higher the shift effort because of the increased mass of the components. Shift effort can also be higher in cold weather because the fluid will be thicker. Medium duty transmissions will not shift as quickly as a Corvette transmission. To reduce shift effort, do not attempt to rush the shift - allow the synchronizers to work as designed. Shifting harder will only increase the chance of rushing past the synchronizer leading to grinding while shifting.

Non-Synchronized Gears
Some light duty truck transmissions in 1st gear (creeper-gear) and reverse gears in various transmissions, along with all gears in some medium duty transmissions, may be non-synchronized. This means there is not a mechanism to match input and output shaft speeds to allow for a smooth shift. This function is left up to the driver. This can be noticed if a shift into 1st or reverse is attempted while the vehicle is rolling or before the input shaft stops rotating leading to a gear grind. The grinding can be reduced by coming to a complete stop and pausing for a moment before shifting into the 1st or reverse gear. Some slight grinding can be expected. In medium duty non-synchronized transmissions, the driver must match input shaft (engine) speed to output shaft (driveshaft) speed with every shift. This can be accomplished by double clutching, or by using other methods. If the driver is not able to perform this function properly, there will be gear grinding with each improperly completed shift. Driver training may be required to correct this condition. Clutch brakes are used in medium duty non-synchronized transmissions to allow a shift into gear at a stop. The clutch brake is used to stop the input shaft from spinning, allowing a shift into gear at a stop without grinding. The clutch brake is activated by pressing the clutch pedal all the way to the floor. When the clutch brake is used, it is possible to have a blocked shift with the vehicle stationary. If this occurs, engage the clutch slightly to rotate the input gear to allow the shift. The clutch brake is intended to only be used while at a stop. Care must be taken to not activate the clutch brake while shifting between gears. This could lead to excessive grinding or a blocked or missed shift.

Skip Shift
Currently, the Cadillac CTS-V, Pontiac GTO, Chevrolet Corvette and Camaro SS (other models may follow) equipped with the 6-speed manual transmission have a feature referred to as a "skip-shift". This feature only allows a shift from 1st to 4th gear when the indicator lamp is illuminated on the dash. Dealers cannot disable this feature as it was established to help meet fuel economy standards. The conditions for this feature are: engine coolant at normal operating temperature, vehicle speed of 24-31 km/h (15-19 mph), 21% or less throttle being used (refer to Service Information or the Owner Manual for more details.)

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


Š 2010 General Motors. All rights reserved.

ecotecturbo

Like i said the clicking is normal, theres nothing they can do to fix it. Ive owned a lsj and lnf and they both clicked and never had a problem.

jsbh2005

They make excusses for everthing now.

I have driven many different manual from cars, trucks, bikes, and others. I have never heard gear slap like this. Any slap that makes a noise that loud means issues in the future. If they want to put it in writting that nothing is going to happen then i will stop requesting them to fix it.

Malaclypse

iTrader: (1)

GM already put it in writing. In that bulletin I posted.

That's GM's stance and that's what they've been saying for years. Vettes and RWD cars with manuals do the same thing. There's alot of lash in the transmissions.

slobalt08

iTrader: (2)

My f23 clicks everytime i shift *shrugs*