LeSabre V6-181 3.0L (1986)
Band Apply Servo: Technical Service Bulletins
Harsh 3-2 Coastdown Bump At 15-22 MPH
V.
HARSH 3-2 COASTDOWN BUMP AT 15-22 MPH
-
1985-87 Century, Electra/Park Avenue, Riviera and LeSabre models with transaxles built prior to December 18, 1986 (Julian Date 352) and
3.8L engines
Service Procedure:
A coastdown bump is obtained by allowing the vehicle to coastdown to 15-22 mph (with closed or zero throttle) and a sudden and forceful apply of the
1-2 band is felt when the transaxle shifts from third to second gear.
A harsh 3-2 coastdown bump may be caused by the 1-2 servo cushion spring. This condition may be corrected by replacing the 1-2 servo cushion spring
with the part listed below. Refer to the chart below to determine the transaxle model and Julian Date when the new springs were first used in production
units.
Transaxle
Build Date/
Transaxle
Build Date/
Model
Julian Date
Model
Julian Date
7FBH
12-11-86/345
7FSH
12-11-86/345
7FCH
12-11-86/345
7FTH
12-11-86/345
7FJH
12-15-86/349
7FZH
12-12-86/346
7FKH
12-11-86/345
7HAH
12-15-86/349
7FNH
12-11-86/345
7HCH
12-18-86/352
7FRH
12-17-86/351
Service Parts Information:
Part Number
Description
8668123
1-2 Servo Cushion Spring (559)
Figure 7
Parts are currently available from GMSPO.
Service Notes:
If the above condition persists make sure the 3-2 coastdown valve (located in the oil pump body) is not stuck and moves freely in its bore.
