Driveline - Clunk On Rapid Tip Out

Article No.
92-24-4

11/18/92

^ TIP-OUT OR DRIVELINE "CLUNK" - 5.0L - DURING QUICK THROTTLE CLOSING

^ NOISE - DRIVELINE "CLUNK" DURING QUICK THROTTLE CLOSING - VEHICLES WITH 5.0L ENGINE

FORD:
1990-91 CROWN VICTORIA

LINCOLN-MERCURY:
1990 TOWN CAR
1990-91 GRAND MARQUIS

CALIBRATION:
8-22E-R00, 8-22G-R00, 8-22J-R00, 8-22C-R00, 8-221-R00, 0-22B-R00, 0-22C-R00

WARNING:
THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.

ISSUE:
A tip-out or driveline "clunk" may occur when the throttle is quickly closed. This condition usually happens while driving in 4th gear, at speeds between 40 to 65 mph (64 to 104 km/h) and NOT during transmission up-shifting or down-shifting. This condition is caused by the operating strategy of the EEC IV processor.

ACTION:
Install a new EEC IV processor with a revised operating strategy.

NOTE:
THE NEW "SERVICE ONLY" PROCESSORS WILL NOT CORRECT TRANSMISSION UP-SHIFT OR DOWN-SHIFT CONCERNS.

1. Check the powertrain and driveline for excessive backlash and service as required.

2. If the "Clunk" is still present, then follow the Quick Test Procedure in the 1990 or 1991 Engine/Emissions Diagnosis Service Manual, depending on the vehicle model year. If fault codes are present, service as required.

3. If the "Clunk" is still present after Steps 1 and 2 are performed, then follow Steps 4 and 5.

4. Replace the thermostat (E6AZ-8575-A) following the procedure outlined in the appropriate Car Service Manual.





5. Replace the EEC IV processor with a new replacement processor as listed in the EEC IV Processor Reference Chart in this article.





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/Name Chart

OTHER APPLICABLE ARTICLES:
NONE

SUPERSEDES:
90-17-4, 91-24-8

WARRANTY STATUS:
Eligible Under Bumper To Bumper For 1991 Model Lincolns and Basic Warranty Coverage For All Other Model Years

0PERATION DESCRIPTION TIME
922404A Includes Check 1.8 Hrs.
Powertrain/Driveline,
Perform Diagnosis, Replace
Thermostat And EEC IV
Processor - Crown
Vic/Grand Marquis
922404B Includes Check 1.7 Hrs.
Powertrain/Driveline,
Perform Diagnosis, Replace
Thermostat And EEC IV
Processor - Town Car

DEALER CODING
BASIC PART NO. CONDITION CODE
DRIVE 56

OASIS CODES:
597997, 610000, 610700