Friday, July 16, 2021

2010 Cadillac Truck SRX AWD V6-3.0L Technical Service Bulletin # 99-04-20-002H Date: 130411

2010 Cadillac Truck SRX AWD V6-3.0L Technical Service Bulletin # 99-04-20-002H Date: 130411



Drivetrain - Information on Driveline Clunk Noise



INFORMATION



Bulletin No.: 99-04-20-002H



Date: April 11, 2013



Subject: Information on Driveline Clunk Noise



Models:



2014 and Prior GM Passenger Cars and Light Duty Trucks



2010 Cadillac Truck SRX AWD V6-3.0L Page 282



Supercede:



This bulletin is being revised to add the 2013-2014 model years. Please discard Corporate Bulletin Number 99-04-20-002G (Section 04 -



Driveline/Axle).



Important



The condition described in this bulletin should not be confused with the following previous bulletins:



- Clunk, Bump or Squawk when Vehicle Comes to Complete Stop or Accelerating from Complete Stop (Replace Rear Drive Shaft



Nickel-Plated Slip Yoke) (Corporate Bulletin Number 01-04-17-004B or later)



- Clunk Noise at Stop or From Launch (Clean/Lubricate Rear Propshaft Slip Yoke Splines) (Corporate Bulletin Number



09-04-21-003D or later)



- Bump Feel/Clunk Noise at Stop or From Launch (Clean/Lubricate Propeller Shaft Slip Yoke Splines) (Corporate Bulletin Number



09-04-17-002E or later)



Some customers of vehicles equipped with automatic transmissions may comment that the vehicle exhibits a clunk noise when shifting between



Park and Drive, Park and Reverse, or Drive and Reverse. Similarly, customers of vehicles equipped with automatic or manual transmissions may



comment that the vehicle exhibits a clunk noise while driving when the accelerator is quickly depressed and then released. Tipping into the throttle



after deceleration can also result in some level of clunk as the driveline is loaded in one direction (coast) then with throttle reapply the driveline gets



loaded in the opposite direction (drive). On manual transmission vehicles depressing the clutch while in a deceleration immediately releases load on



the driveline and may produce a clunk noise as the driveline unloads.



Note



Compare this complaint vehicle to a like vehicle. If the results are the same, this is a normal condition. For additional diagnostic information, refer



to the appropriate Service information.



Whenever there are two or more gears interacting with one another, there must be a certain amount of clearance between those gears in order for



the gears to operate properly. This clearance or freeplay (also known as lash) can translate into a clunk noise whenever the gear is loaded and



unloaded quickly, or whenever the direction of rotation is reversed. The more gears you have in a system, the more freeplay the total system will



have.



The clunk noise that owners sometimes hear may be the result of a buildup of freeplay (lash) between the components in the driveline.



For example, the potential for a driveline clunk would be greater in a 4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. This is



because in addition to the freeplay from the rear axle gears, the universal joints, and the transmission (common to both vehicles), the 4-wheel drive



transfer case gears (and their associated clearances) add additional freeplay to the driveline.



In service, dealers are discouraged from attempting to repair driveline clunk conditions for the following reasons:



- Comments of driveline clunk are almost never the result of one individual component with excessive lash, but rather the result of the added



affect of freeplay (or lash) present in all of the driveline components.



Because all of the components in the driveline have a certain amount of lash by design, changing driveline components may not result in a



satisfactory lash reduction.



- While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.



- For additional diagnostic information, refer to the appropriate Service Information.

No comments:

Post a Comment