A/T - Bucking Condition On Long Decelerations

89Ford21

TRANSMISSION-A4LD-TRAILER HITCHING ON LONG DECEL AT HIGH ALTITUDE

Article No. 89-13-11




MERKUR: 1988-89 SCORPIO


ISSUE: A bucking condition (trailer hitching) on a long decel from highway speeds at high altitudes may be caused by the torque converter. The torque converter's lock-up function may hunt between the locked and unlocked modes on long decels.

ACTION: Install a vacuum delay valve in the vacuum line to the vacuum switch. Refer to the following procedure for service details.

1. Check to see that "trailer hitching" exists by test driving the car on a long decel from highway speeds.

2. Disconnect the electrical connection at the vacuum switch. Refer to the Scorpio Shop Manual, page 34-22-3 for service details.

3. Retest the car.

4. Check to see that the condition is gone with the vacuum switch disconnected.

5. Cut the vacuum line near the electrical connection on the left hand fender apron.

6. Install a vacuum delay valve in the vacuum line (cut in Step # 5) to the vacuum switch. Insert the delay valve connectors into each end of the cut vacuum line.

Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

PART NUMBER PART NAME CLASS

D8AZ-12A208-A Vacuum Delay Valve WG

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage, Powertrain Warranty Coverage

OPERATION DESCRIPTION TIME
891311A Install Vacuum Delay Valve 0.7 Hr.

DEALER CODING
BASIC PART NO. CONDITION CODE
7902 09
OASIS CODES: 5300, 630200, 632000