A/T - Shift Busyness (Cycling Between 3rd and 4th Gears)
Model Year 1983Bulletin No. 83-169
File in Group 70
Number 30
Date Aug. '83
SUBJECT: SHIFT "BUSYNESS" (CYCLING BETWEEN FOURTH AND THIRD GEARS)
MODELS AFFECTED: 1982-1983 RIVIERAS EQUIPPED WITH 5.0L ENGINES (VIN CODE Y) AND THM 325-4L MODEL "OE" TRANSMISSIONS
Some 1982 and 1983 Rivieras with 5.0L engines (VIN code Y) and THM 325-4L model "OE" transmissions may experience a shift "busyness" which is most noticeable while driving up inclines and in cruise control. "Busyness" refers to cycling between fourth and third gear.
Beginning on February 2, 1983, a revised control valve assembly went into production for all 1983 THM 325-4L "OE" model transmissions to correct this condition.
When servicing any 1982 or 1983 THM 325-4L "OE" model transmission produced before the above date for this "busyness" condition, order service package number 8635953. This package contains:
1) Control valve assembly
2) Pressure regulator spring
3) Intermediate servo cushion spring
4) Control valve spacer plate
5) 3-4 accumulator spring
6) Instruction sheet
Refer to the instruction sheet contained in the service package as well as the service manual for proper removal and installation procedures of the items contained in this package.
NOTICE: To complete this modification on 1982 Rivieras, the cruise control servo should be checked. If the servo housing is black in color, it should be replaced with servo part #25031846, which is gray in color.