Clunky 5spd
Thread Starter
Joined: 09-06-2009
Posts: 8
From: San Diego
Clunky 5spd
I've got about 1200 miles on my '09 SS. It's a 5sp manual and totally stock.
I'm not new to driving a manual transmission vehicle, but I can't say that I'm the best either.
No matter how hard I try for an economical smooth shift, the transmission has a sort of clunk to it. I don't necessarily feel it through the clutch, floor or shifter, but it's definitely audible.
Now to find another HHR or Cobalt with a 5spd to compare probably wouldn't be that easy.
Is this what it's supposed to sound like? Is it because it's a fwd car? My girlfriend has a 5spd '99 Nissan sentra and it doesn't clunk.
Appreciate any insight!
I'm not new to driving a manual transmission vehicle, but I can't say that I'm the best either.
No matter how hard I try for an economical smooth shift, the transmission has a sort of clunk to it. I don't necessarily feel it through the clutch, floor or shifter, but it's definitely audible.
Now to find another HHR or Cobalt with a 5spd to compare probably wouldn't be that easy.
Is this what it's supposed to sound like? Is it because it's a fwd car? My girlfriend has a 5spd '99 Nissan sentra and it doesn't clunk.
Appreciate any insight!
Senior Member
Joined: 08-15-2009
Posts: 126
From: Colorado
Hi, I have @ 2300 on my 09, I know what your talking about. I just thought it's the trade off you make for a trans that can handle some power. No offense plz, but a 99 Sentra wasn't built to be a 0-60/ 6.3 sec car, and Nissan has done alot of nice things with their manuals( I used to sell them). If your really worried just call your dealer, as new as it is...it's on them. Peace.
Senior Member
Joined: 11-27-2007
Posts: 1,115
From: Austin, Texas
I have about 36,000 now, with "power up" mods for most of those miles, and I have never had any "clunk" sounds from my trans, so I really don't have a clue as to what you are referring to. Mine has LSD, if yours is a non LSD maybe there is something going on there.
Thread Starter
Joined: 09-06-2009
Posts: 8
From: San Diego
jerdog, I love your rationale! And you're right, the 1.6l nissan with 41mpg has no guts...
My car does had the standard differential.
Thanks for the responses. I haven't ruled out my technique. I'm used to my Corvair that has about half the hp and about 8x the pedal pressure.
My car does had the standard differential.
Thanks for the responses. I haven't ruled out my technique. I'm used to my Corvair that has about half the hp and about 8x the pedal pressure.
Senior Member
Joined: 06-03-2008
Posts: 123
From: Victoria
My 5-speed HHR SS clunks between shifts, particularly at slow speeds. It also whines, jerks a little, and occasionally feels a bit crunchy going in to gear.
However, in 20,000 miles of hard driving, it's never let me down, never really missed a gear, and is still going strong even with a tune
However, in 20,000 miles of hard driving, it's never let me down, never really missed a gear, and is still going strong even with a tune
Senior Member
Joined: 08-06-2009
Posts: 181
From: Crestview,FL
Mine also makes the noises but figured it's all normal since it seems to drive fine. Here's a bulletin GM put out about manual transmissions
#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
--------------------------------------------------------------------------------
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).
--------------------------------------------------------------------------------
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 Duramax®) will have reduced noise levels as compared to vehicles without (for example, a 4500 Kodiak with the 6-speed manual and Duramax®). 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.)
#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
--------------------------------------------------------------------------------
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).
--------------------------------------------------------------------------------
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 Duramax®) will have reduced noise levels as compared to vehicles without (for example, a 4500 Kodiak with the 6-speed manual and Duramax®). 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.)
Joined: 08-18-2010
Posts: 3
From: Saxapahaw, NC
Hi 66Vair,
The transmission or clutch clunk is normal on your HHR SS, and yes you do normally hear it with high performance transmissions. The reason why you hear it is because of transfer of power between the transmission and the drive shaft occuring too fast. The sound does bother me and generally you do hear it more often during an economical smooth shift, so here are some of my suggestions to avoid it or reduce its occurance:
Basically, you want to try to match the engine RPM to the speed of your car while shifting. This requires getting used to driving your SS:
a. While starting off or shifting, and while releasing your cluth make sure you apply more and more gas. Do not wait until after the clutch engages. While releasing the cluth, time it so that you are simultaneously providing more gas. While engaging the clutch from startup this transmission/clutch requires slightly more engine RPM than the easy clutch on your Nissan. Think of it as if you are using your gas pedal as a reverse clutch pedal.
b. While slowing down in 1st, 2nd and sometimes 3rd, do not abruptly release the gas pedal. Most certainly the transmission would go "clunk, clunk, clunk". Instead depress the clutch half-way then reduce the gas and apply your brakes and release the clutch fully.
c. You could also read up on "double clutching" with manual transmission, a method used by car racers to closely match the driveshaft and engine RPMs for a smooth shift.
Regards,
cgb
The transmission or clutch clunk is normal on your HHR SS, and yes you do normally hear it with high performance transmissions. The reason why you hear it is because of transfer of power between the transmission and the drive shaft occuring too fast. The sound does bother me and generally you do hear it more often during an economical smooth shift, so here are some of my suggestions to avoid it or reduce its occurance:
Basically, you want to try to match the engine RPM to the speed of your car while shifting. This requires getting used to driving your SS:
a. While starting off or shifting, and while releasing your cluth make sure you apply more and more gas. Do not wait until after the clutch engages. While releasing the cluth, time it so that you are simultaneously providing more gas. While engaging the clutch from startup this transmission/clutch requires slightly more engine RPM than the easy clutch on your Nissan. Think of it as if you are using your gas pedal as a reverse clutch pedal.
b. While slowing down in 1st, 2nd and sometimes 3rd, do not abruptly release the gas pedal. Most certainly the transmission would go "clunk, clunk, clunk". Instead depress the clutch half-way then reduce the gas and apply your brakes and release the clutch fully.
c. You could also read up on "double clutching" with manual transmission, a method used by car racers to closely match the driveshaft and engine RPMs for a smooth shift.
Regards,
cgb
Platinum Member
Joined: 12-06-2009
Posts: 11,721
From: Alabama
Clunk,clunk,clunk.
Yes it does.My 2010, 5 speed,w/LSD loves to clunk but it just appears normal. It is not a loud or harsh clunk, but noticable.
The one thing I'm trying to teach my right foot.Do not abruptly and fully let up on the accelerator! Definite clunky feedback when you do this.
IMO these are really two different but some what related issues. I think it has to do with torque numbers and trans/clutch design.Maybe one of the forum gurus could explain it better. I can turn the wrenches but can't explain the results.
The one thing I'm trying to teach my right foot.Do not abruptly and fully let up on the accelerator! Definite clunky feedback when you do this.
IMO these are really two different but some what related issues. I think it has to do with torque numbers and trans/clutch design.Maybe one of the forum gurus could explain it better. I can turn the wrenches but can't explain the results.