Cooling Fan - Vibration
08/23/96H453
SUBJECT:
Cooling Fan Vibration
MODEL:
Range Rover 4.0/4.6
AFFECTED VEHICLES:
LP 340675 to 343682
LH
LJ
LD
DETAIL
Information provided by our supplier of viscous fan units has identified that a number of units have been machined incorrectly which may result in a fan assembly that is out of balance. A unit that is suspect can be identified by the fan exhibiting vibration under varying engine RPM. The assembly can be observed running out/oscillating as the engine RPM is increased.
ACTION REQUIRED
At the first opportunity, visually inspect that the fan has not already been updated by checking for the yellow identification mark on the inner ring of the fan as detailed in the illustration. Replace the viscous unit/water pump as required by referring to the process below.
PROCEDURE
Checking Procedure
Fan with clutch (Range Rover 4.0/4.6)
Process to determine if viscous unit is running true:
1. Open hood and secure.
2. Release the fan top cover toggle clamps and remove cover.
3. Check that the fan is not marked with a yellow dot (see illustration item D). If mark is present no further action is required.
Care must be taken to avoid the rotating fan when undertaking the following inspection process.
4. Start engine.
5. Accelerate (by means of the throttle control cable) so that the fan disengages and switches off (when disengaged there is little noise).
6. while continually increasing engine RPM up to a maximum of 3000 RPM, observe if the fan begins to oscillate (vibration, undulation effect). Up to 0.16in (4 mm) run out is acceptable. and no further action is required.
7. Should the fan run out be between .16 in-.28 in (4 mm-7 mm) the viscous unit must be replaced. If the fan run out is more than .28 in (7 mm), replace the viscous unit and water pump. (see illustration).
8. Apply yellow paint identification to all inspected or reworked vehicles. (see illustration).
A = Run out within .16 in (4 mm) 0K-No further action. Apply yellow paint at D on inner ring.
B = Run out .16 - 28 in (4 to 7 mm) - Replace viscous unit and apply yellow paint at D on inner ring.
C = Run out .28 in (7 mm) or greater-Replace viscous unit and water pump, and apply yellow paint at D on inner ring.
D = Yellow paint identification on inner ring of fan.
WARRANTY:
Normal warranty policy and procedures apply
C0MP.C0DE:
B453
SRO:
USA
B453 Option 1 - Inspect only - 0.25 hour
B453 Option 2 - Inspect/replace viscous unit - 0.45 hour
B453 Option 3 - Inspect replace viscous unit & Water pump renew - 1.55 hour
NOTE:
A $10.50 coolant allowance will be credited with option 3.