GM Service Manual Online
For 1990-2009 cars only
Table 1: Noise when idling
Table 2: Noise when selector is moved
Table 3: Noise when vehicle is moving
Table 4: Noise when shifting

Noise when idling

Checks

Causes

Visual check

    • Dent in oil pan
    • Oil filter clogged

Oil pump

Damage or wear tot he oil pump gears

Error in engine auxiliaries

Noisy engine auxiliaries

Noise when selector is moved

Checks

Causes

Line pressure OK

    • Low clutch assembly
    • Burn or wear of the low clutch. Refer to Low Clutch Disassemble .
    • Reverse clutch assembly
    • Burn or wear of the reverse clutch. Refer to Reverse Clutch Disassemble .

Line pressure out of range

    • Operation of the control valve spool
    • Seized or broken pump gears

Noise when vehicle is moving

Checks

Causes

Tone change according to engine speed

Visual check

    • Dent in oil pan
    • Oil filter clogged

Tone change according to vehicle speed in specific range other than third gear

Damage or abnormal wear of the planetary gear

Tone change according to vehicle speed in all ranges

    • Damage or abnormal wear of output and final gears
    • Flaw or abnormal wear of the low 1-way clutch
    • Flaw or abnormal wear each bearing
    • Rattle or abnormality in the vehicle drive shaft.
    • Abnormal wear or flaws in the vehicle wheel bearing

Noise from engine auxiliary

Errors related to engine auxiliary

Noise when shifting

Checks

Causes

Line pressure OK

Clutch slip or error when shifting/Planetary gear noise when shifting

    • Damaged planetary gear
    • Abnormal wear to planetary gear

Line pressure out of range

    • Damage planetary gear
    • Operation of the control valve spool