A/T Throttle Valve - Buzz
Bulletin 86-7125-4Date Apr. '86
Ref. No. 86-092-7125
SUBJECT: THROTTLE VALVE BUZZ
MODELS AFFECTED: 1985 & 86 SKYLARKS & CENTURYS EQUIPPED WITH 2.8L, V-6 ENGINES (VIN CODE "X & W") & THM 125C TRANSAXLES
THM 125/125C TRANSMISSION I.D. NAMEPLATE YPSILANTI, MICHIGAN:
THM 125/125C TRANSMISSIONI.D. NAMEPLATEWINDSOR, CANADA:
A 1985 or 1986 THM 125C transaxle built prior to October 29, 1985 (Julian date 302) in Windsor, or prior to December 9, 1986 (Julian date 343) in Ypsilanti, may exhibit a throttle valve buzz condition. (See illustration).
Beginning on the listed dates, a new valve body to case cover spacer plate was introduced to eliminate the buzz by reducing the diameter of the 1-2 accumulator valve feedback orifice.
To correct a throttle valve buzz condition for models built before these dates, replace the original valve body to case cover spacer plate with the new spacer plate, Part Number 8660569.
Refer to the appropriate Service Manual for removal and installation procedures.