A/T - THM 440 Harsh Shift 3rd to 2nd Gear
87cad7Bulletin No. T 88-32
File in Group 7
Number 174
Corp. Ref. No. 777140R
Date Oct. '87
SUBJECT: HARSH 3-2 SHIFT - THM 440-T4
MODELS AFFECTED: 1985-1987 DE VILLES AND FLEETWOODS 1986 ELDORADOS AND SEVILLES
This bulletin supplements information previously published in Serviceman Bulletins T-87-43, T-87-44 and T-87-52.
Some 1985-1987 De Villes and Fleetwoods, and 1986 Eldorados and Sevilles equipped with THM 440-T4 transaxles may exhibit very harsh, or intermittent harsh 3-2 down shifts. Very harsh 3-2 part throttle down shifts between 20-40 mph may be caused by a missing or mislocated #2 (3-2 control) checkball. An intermittent harsh 3-2 down shifts during a part throttle detent down shift may be caused by a broken 3-2 line control retainer.
FIGURE 1 - CHECK BALL LOCATIONS - CHANNEL PLATE:
VERY HARSH, PART THROTTLE 3-2 DOWN SHIFTS BETWEEN 20-40 MPH
To repair this condition, remove the valve body and inspect for the checkball. A mislocated checkball may have bent the spacer plate, in which case the spacer plate must be replaced (see Figure 1).
FIGURE 2 - 3-2 LINE CONTROL VALVE LINE UP:
INTERMITTENT HARSH 3-2 DETENT DOWN SHIFT
To repair this condition, remove the transaxle side cover and replace the broken retainer (see Figure 2).
Part Number Description
8658678 Retainer, 3-2 Line Control
For warranty purposes, use Labor Operation:
K 6570 4.8 hrs. Check Ball Missing or Mislocated
(Includes replacement of 3-2 line control retainer if required)
T6258 2.9 hrs. (C-car) Retainer, 3-2 Line Control
3.2 hrs. (E/K)