LeSabre V6-231 3.8L VIN C SFI (1990)
A new two plate 4th clutch assembly (501) and apply plate (502) are used to replace the single plate 4th clutch assembly for some 1990
HYDRA-MATIC 4T60 (THM 440-T4) transaxles. The extra plate was added for higher torque engine applications. For this change to be
implemented, the following parts were modified:
^
4th clutch plates assembly (fiber) are thinner by 0.51 mm (0.020"). The fiber material is the same thickness; only the steel part of the
plate was made thinner. The two plate assembly has four white stripes, while the single plate fiber plate has four green stripes.
^
4th clutch reaction plates are made thinner by O.1 mm (0.004") for the two plate assembly.
^
4th clutch apply plate does not have the step used on the single apply plate, but it does have a slight machined-in taper.
DATE OF PRODUCTION CHANGE
Starting SOP 1990, all transaxle models covered by this bulletin were built with the two plate 4th clutch assembly.
When servicing a 1990 transaxle model, rebuild/replace the 4th clutch components with the same type (single or two plate) unless the 4th clutch is
distressed; see Section II of this service bulletin for service procedure. The part numbers for the two plate 4th clutch assembly components and overhaul
repair packages are listed under "Service Parts Information".
IMPORTANT:
Do NOT interchange individual components or the entire 4th clutch assembly into a unit that was not originally built with it.
Calibrations of the 4th clutch apply feel will be affected and could create durability concerns.
SERVICE PARTS INFORMATION
Model
Part Number
Description
Year
Model Usage
** 18017246
Plate Assembly - 4th Clutch
1990
OAAH
OABH OAFH
(fiber for two plate type)
OAJH
OANH OATH
*OBAH
*OBDH *OBFH
*OBHH
*OBJH
*OBPH
*OBWH
** 8661004
Plate Asm. - 4th Clutch Apply
1990
OAAH
OABH
OAFH
(for two plate type)
OAJH
OANH
OATH
*OBAH
*OBDH *OBFH
*OBHH
*OBJH
*OBPH
*OBWH
** 8661006
Plate Asm. - 4th Cl. Reaction
1990
OAAH
OABH
OAFH
(steel for two plate type)
OAJH
OANH
OATH
*OBAH
*OBDH *OBFH
*OBHH
*OBJH
*OBPH
*OBWH
** 8662986
Pkg. - Overhaul Repair Complete
1990
OAAH
OABH
OAFH
(Two plate clutch models)
OAJH
OANH
OATH
*OBAH
*OBDH *OBFH
*OBHH
*OBJH
*OBPH
*OBWH
8662989
Pkg. - Overhaul Repair Complete
1990
*OBAH
*OBDH *OBFH
(Single plate clutch models)
*OBHH
*OBJH
*OBPH
*OBWH
OCHH
OCJH
OLMH
OLNH
The above part numbers do not currently show Buick usage at GMSPO, although they are correct for two plate applications.
Parts are expected to be available for part numbers 18017246, 8661004 and 8661006 on 12-15-89. Until then, normal part orders will not be accepted by
GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to
waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as
incorrectly ordered while the 400 control is in place.
Parts are currently available for part numbers 8662986 and 8662989 from GMSPO.
Models were produced for a short time from SOP 1990 to July 31, 1989 (Julian Date 212), with the two plate 4th clutch. Starting July 31, 1989 (Julian
