Driveline - Vibration On Smooth Road
NO: 09-07-94GROUP: Engine
DATE: Apr. 22, 1994
SUBJECT:
Smooth Road Driveline Vibration
MODELS:
1990 - 1994 (BD) Laser/Talon
SYMPTOM/CONDITION:
Vehicle vibration, similar to tire/wheel shake, while traveling on smooth roads at 45 to 55 MPH.
DIAGNOSIS:
Test drive the vehicle on a smooth road surface at the speed that the vibration is reported to occur.
NOTE:
PERFORM THIS TEST DRIVE ONLY WHEN ROAD AND TRAFFIC CONDITIONS ARE SAFE.
1. For manual transaxle equipped cars - disengage the clutch by depressing the clutch pedal when the vibration is encountered and note if the vibration goes away.
2. For automatic transaxle equipped cars - shift the transaxle into neutral when the vibration is encountered and note if the vibration goes away.
If, while performing the test drive the vibration is still present, the condition is not related to the vehicle driveline. Items that should be inspected/checked are:
A. Wheels - look for any sign of damage or run out variation.
B. Tire pressure or unusual tire wear.
C. Wheel balance (use an on car balancer if possible).
If the vibration disappears while performing the test drive, inspect the following:
A. Visually check the engine mount, transaxle mount, and the roll stopper mounts for interference, twisting, tearing or breakage of the rubber isolators. Reposition or repair these items as required.
B. Check the lower radiator mounts to make sure they are fully seated in their brackets and inspect their condition. Reposition or repair the radiator mounts as required.
C. Check the engine wiring harness for interference with the lower radiator. Reposition as required.
D. Check the upper radiator mounting posts to make sure they are centered in their brackets. Reposition as required.
If the vibration is still present after checking and correcting the above items, proceed to the repair procedure.
PARTS REQUIRED:
REPAIR PROCEDURE:
This bulletin involves replacing the engine and transmission mounting brackets with brackets that have a durometer better suited to this application.
1. Following the procedures listed in the applicable Service Manual, replace the engine and the transaxle mounting brackets with the appropriate one listed in the parts section of this bulletin.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 09-40-20-98 2.0 Hrs.
FAILURE CODE: P8 - New Part