A/T - THM 440-T4 Harsh 1-2 Shift
87cadillac8Bulletin No. T-88-45
File in Group 7
Number 176
Corp. Ref. No. 777147
Date Nov. '87
SUBJECT: HARSH 1-2 SHIFT - THM 440-T4
MODELS AFFECTED: 1985-1987 DE VILLE AND FLEETWOOD 1986-1987 ELDORADO AND SEVILLE
Some 1985-1987 DeVilles and Fleetwoods, and 1986-1987 Eldorados and Sevilles may experience a consistently harsh 1-2 shift condition at any throttle angle and any altitude.
This harsh shift condition may be caused by a blocked or partially drilled 2nd clutch feed passage in the case.
Figure 1 - Bottom Pan, Filter, Accumulator, and Governor Cover Assembly:
FIGURE 2 - CASE PASSAGES - BOTTOM VIEW:
FIGURE 3 - CASE PASSAGES - CHANNEL PLATE SIDE:
To repair this condition inspect the 2nd feed passage for blockage or incomplete drilling operation. To perform this inspection, remove the transaxle oil pan, filter, accumulator cover (with feed pipes and retainer), accumulator cover spacer plate, and gaskets (Figure 1). Inspect the 2nd clutch passage by measuring the depth of the hole, which should be a minimum of 72 mm (2-13/16") as shown in Figures 2 and 3. If the 2nd clutch passage is properly drilled, refer to Section 7A1 of the appropriate Service Information Manual for possible causes of a harsh 1-2 shift.
If the passage is not properly drilled:
1. Remove the transaxle from the vehicle and disassemble components up to and including the channel plate.
2. Mark an 8.5 mm (21/64") drill bit at 72 mm (2-13/16") from the end using a drill stop or some other acceptable method. From the oil pan side of the case, finish drilling the 2nd clutch passage to the proper depth as marked on the drill bit.
NOTE: DRILLING TOO DEEP INTO THE 2nd CLUTCH PASSAGE WILL RESULT IN DAMAGE TO THE CASE.
3. Remove metal chips caused by drilling, and thoroughly flush die repaired case passages with clean solvent.
4. Reassemble the transaxle.
For warranty purposes, use Labor Operation T6260 at 5.5 hours for DeVilles and Fleetwoods and 6.2 hours for Eldorados and Sevilles.