Vibration at All Speeds; Damaged Transmission Tailshaft Bushing; Cracked Exhaust at Catalytic Converter - keywords 2.8 3.5 4L60E broken crack leak L52 LK5 noise prop propshaft shaft shake seal short

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

2WD Regular Cab Chevy Colorado and GMC Canyons built between November 13, 2003 and December 31, 2003 may exhibit a low frequency vibration or thumping noise at low speeds which may sound like a propshaft boom noise at higher speeds. If vehicles are driven long enough with this condition, damage may occur to the transmission tail shaft bushing, and/or cracking may occur in the exhaust system at the catalytic converter. This condition may be caused by a propshaft which is up to one inch (25.4mm) too short, which causes excessive driveline motion.

Any Colorado or Canyon with build dates between November 13, 2003 and December 31, 2003 with a complaint of vibration, transmission tailshaft housing/bushing leak or damage, or exhaust system damage at the catalytic converter, needs to have the propshaft inspected for being too short. A good propshaft has a length of the 53.34 inches or 1354.8MM, measured from the center of the U-joint to the center of the U-joint. Propshafts which have been found to be short, and which can cause these conditions, are approximately one inch or 25.4 mm shorter than this specification. Replace the propshaft if this condition is found, in addition to repairing any damage to the transmission and/or exhaust system.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.