A/C- Blend Flap Vibration/Noise
NO.80/02/96/US
DATE
11/08/96
SUBJECT
HVAC - Blend Flap Vibration Service Fix
MODEL
Range Rover 4.0/4.6
AFFECTED VEHICLES
LP up to TA350615
DETAIL
In cold ambient conditions below 50°F (10°C) the right blend flap may create a vibration between the flap and the heater assembly body. To remedy this noise, a neoprene o-ring can be fitted to the servomotor's spindle, damping the vibration. The neoprene o-ring has been introduced on the assembly line at VIN TA350615, and vehicles after this VIN should not exhibit the blend flap vibration.
ACTION REQUIRED
Should a customer complain of a vibration or throbbing sound coming from the fascia, investigate whether or not it is a blend flap vibration. If upon further investigation the blend flap is found to be the origin of the fascia vibration, follow the procedure below to fit the neoprene o-ring.
PARTS INFORMATION
STC3259OR: Neoprene O-ring
Tools and Supplies:
Snap On PN: SSDE48 Thin-blade screwdriver Dumdum adhesive
PROCEDURE
REMOVAL
NOTE: The suspect blend flap servomotor is on the right-hand side. When the right blend flap servomotor begins to vibrate it induces the vibration on the left-hand side. Therefore, fitting the neoprene o-ring to the right blend flap servomotor should eliminate left blend flap vibration.
IMPORTANT: Ensure that the vehicle battery (negative terminal) is disconnected before proceeding to step 1. A twenty minute delay is recommended prior to removal of air bag module.
WARRANTY
Normal warranty policy and procedures apply.
COMP. CODE
8M4
SRO
82.20.89/26: Blend flap vibration fix - 1.5 hr
Passengers side:
1. Open glove box. Remove 5 screws securing glove box liner to fascia (Fig. 1).
2. Lower glove box liner. Release 2 clips to disengage glove box release cable latch from location.
3. Release and disconnect air bag module multi-plug (Fig. 2). See Section 75 of workshop manual, Passenger Side page 1.
4. Remove 4 bolts and washers (E-10 Torx Bit) securing air bag module to fascia frame.
5. Carefully remove burwalnut glovebox fascia strip to allow removal of airbag (Figure 1).
5. Carefully remove air bag module and store correctly. Note position of any shims on air bag module for correct installation.
6. Remove lower crossduct and duct extension.
7. Remove posidrive single screw securing top crossduct, and remove duct.
NOTE: In order to access the screws securing the right blend servomotor, a hole may be drilled into the ductwork. If a drill is used, ensure a reasonable fit within the fascia frame, and that the remaining internal components are unharmed in the process.
8. Using a thin-bladed screwdriver (Snap On PN: SSDE48 or equivalent), puncture rear duct work to access screws securing right blend servomotor. If puncture does not line up with servomotor screws maneuver duct to line up (Figure 3).
NOTE: Heating the blade of the screwdriver will aid in puncturing the duct.
9. Carefully remove posidrive screws securing right blend servomotor (Figure 4).
10. Remove servomotor.
REPLACEMENT
1. Fit 0-ring to right blend servomotor spindle.
NOTE: Moving the short lever slightly on top of the blend door may assist in fitting the spline to the blend door spindle (Figure 5). Ensure that the blend flap is in the original position before installation.
2. Make sure that right blend servomotor's spline fits into blend door spindle, and install on heater assembly.
3. Perform the following steps to install each servomotor retaining screw:
^ Insert screwdriver into existing duct hole made during removal.
^ Apply dumdum on the servomotor securing screw head.
NOTE:A pair of long reach needle nose pliers may help load the screw into the motor.
^ Load screw with dumdum adhesive onto end of screwdriver protruding through ductwork (Figure 6).
^ Carefully guide screw into motor and tighten
^ Plug holes in ductwork with dumdum adhesive (A/C insulation tape) or sealant to prevent whistling or air bleed.
4. Repeat step 3 for remaining servomotor securing screw.
5. Install all trim panels and fixtures in reverse order of removal.
6. Connect negative battery terminal.
7. Complete servomotor initialization process using Testbook to ensure proper servomotor operation.