A/T - THM125C Noise Diagnosis Update

Number: 87-64

Section: 7A

Date: JAN., 1987

Subject: 1987 SERVICE MANUAL UPDATE
NOISE DIAGNOSIS


Model and Year: VEHICLES EQUIPPED WITH
THM 125C TRANSAXLES

TO: ALL CHEVROLET DEALERS


This bulletin provides noise diagnosis information for the 1987 THM 125C Transaxle Service Manual, Hydraulic Diagnosis Section.

Before diagnosing the transaxle for a noise related condition, verify presence of noise in relation to drive range, vehicle speed, and engine rpm. Make certain the noise condition is not external to the transaxle. Refer to the noise and vibration analysis procedure, Section 7a of the Service Manual.

A check for loose or misaligned components within the engine compartment which could contact the engine or transaxle during engine roll (engine torque movement) should also be made.

THM 125C NOISE DIAGNOSIS:

THM 125C Noise Diagnosis:

THM 125C Noise Diagnosis:

THM 125C Noise Diagnosis:

Follow the preliminary check procedure as outlined in the oil pressure chart included in the THM 125C hydraulic diagnosis section.

- Transaxle fluid level

- Condition of fluid (including presence of bubbles or contaminants on fluid level indicators)

- Oil pressures as listed