Many noises believed to be coming from the transmission
may be originating from other sources such as tires, road surfaces, wheel
bearings, the engine or the exhaust system. These noises may vary according
to vehicle size, type, and amount of body insulation used. A thorough and
careful check should be made to determine the source of the noise before
disassembling the transmission. The transmission gears, like any other mechanical
device, are not absolutely quiet and will exhibit some normal operating noise.
The following is a suggested approach to verify the suspected transmission
noises.
- Select a smooth, level asphalt road to reduce tire noise.
- Drive the vehicle until the coolant has reached normal operating
temperature.
- Record the speed and the gear range at which noise, if any, occurs.
- Check for noises with the engine running and the vehicle stopped.
- Determine in which of the following drive conditions the noise
is occurring:
• | Drive-light acceleration or heavy pull. |
• | Float-maintaining constant vehicle speed at light throttle with
the transmission in gear. |
• | Coast-partially or fully closed throttle with the transmission
in gear. |
- After road testing the vehicle, refer to
Noisy in All Gears
,
Noisy in Neutral with Engine Running
,
Noisy in First Gear Only
,
Noisy in Second Gear Only
,
Noisy in Third Gear Only
,
Noisy in Fourth Gear Only
,
Noisy in Fifth Gear Only
,
Noisy in Reverse Only
,
Transmission Slips Out of Gear
,
Gears Will Not Disengage
,
Hard Shifting Effort
.