A/T - Delayed Engagement

Bulletin No. T 84-38A
File In Group 7
Number 97
Date Mar. '84
SUBJECT: DELAYED ENGAGEMENT - THM 325-4L

MODELS AFFECTED: 1982-1983 ELDORADO AND SEVILLE
This bulletin supersedes Serviceman Bulletin 84-38, Group 7, #93, which should be destroyed, and Section 1 of Serviceman Bulletin 82-59, Group 7, #38.

Some 1982 and 1983 Cadillacs equipped with a THM 325-4L may experience a delayed transmission engagement when shifting from Park and/or Neutral to Drive and/or Reverse upon initial start up after being parked for several hours. This condition may be caused by a loss of pump prime.

A revised service procedure, which includes the installation of a transmission pump intake check valve (P/N 8635971) and significantly reduces repair time, has been developed to correct this condition.

FIGURE 1 - Installing Pump Intake Check Valve:

Service Procedure

1. Remove the transmission oil pan and filter as outlined in Section 7A of the appropriate Service Information Manual. Make sure that the filter to case O-ring is also removed from the pump intake hole in the transmission case.

2. Install a service part pump intake check valve (P/N 8639810) into the case pump intake hole (refer to Figure 1). This can be done by using a 1/2" deep well socket and extension, or equivalent, as a driver. Be sure that the valve is fully seated and the valve stem undamaged after installation.

3. Steps 1 and 2 should, in most cases, eliminate delayed engagement conditions. However, if the condition persists after following this procedure, it may be necessary to proceed to step 4 and install service package P/N 8635967. This includes a #8-32 set screw to be used for plugging the line bleed orifice in the case cover and a new design pressure regulator valve bushing. When installing this kit, it is essential to use both parts to ensure proper transmission operation. It is not necessary to remove the check valve installed in step 2.

4. Remove the transmission from the vehicle and disassemble the case cover as listed in the appropriate Service Information Manual.

5. Press the drive sprocket support out of the case cover (refer to SIM Section 325-4L, Figure Nos. 153 and 157).

NOTE: The case cover must be supported as outlined in the Service Information Manual to prevent damaging the cover.

FIGURE 2 - CASE COVER PLATE:

6. Remove the line bleed orifice cup plug from either side with a 1/8" punch (refer to Figure 2).

FIGURE 3 - CASE COVER PLATE:

7. Tap screw threads into the line bleed orifice hole using a #8-32 tap. Run the tap into the hole from the sprocket support side approximately halfway through; do not tap the hole all the way through (refer to Figure 3).

8. Coat the set screw with Loctite and install into the case cover with a 5/64" allen wrench until snug.

9. Remove the pressure regulator bushing from the case and install the new bushing.

Warranty Information

Install pump intake check valve, steps 1-2, Labor Operation No. T6093 for .6 hour.

Add to install service package P/N 8635967, steps 3-9, Labor Operation No. T6088 for 5.2 hours.