I recently replaced my SC300 center vent assembly because of the cracks in the corners of the frame. Following is the procedure I used to remove the vent assembly. You will need a screwdriver, Phillips screwdriver, very small blade screwdriver, 12mm socket, 10mm socket, and socket driver. Please read all instructions and review photos before starting.

WARNING - this procedure requires removal of the passenger side airbag - REMOVE AT YOUR OWN RISK! I WILL NOT BE RESPONSIBLE FOR ANY INJURY OR MALFUNCTION CAUSED BY THIS PROCEDURE. Before continuing, move the passenger seat all the way back. Turn off the ignition and remove the key. Disconnect the battery and wait 90 seconds. DO NOT TURN THE KEY UNTIL THE AIRBAG IS RECONNECTED!

1. Open the glove box and use a screwdriver to remove the access panel in the top of the glove box towards the left rear. Pull the panel down. Remove the the 2 silver screws and the yellow connector. Note how the cables are connected. Using a small screwdriver, carefully open the connections and remove the airbag wires. Here is how the connector looks after opened and disconnected:



2. Remove the glove box. Begin by removing the 2 square screw covers behind the glove box door. Carefully separate the bottom kick panel apart from the lower glove box panel just enough to expose the 2 Phillips screws (see photo below). Remove the 2 Phillips screws. Remove the 2 Phillips screws behind the square covers that you previously removed. Remove the glove box by gently pulling it from behind the door latch bracket. With the glove box slightly pulled out, remove the 2 wires connected on the left side of the glove box. Completely remove the glove box and set it aside where it will not be damaged.

3. Remove the glove box latch by removing 2 Phillips screws.

4. Remove the air bag. It is held in place by 3 Phillips screws, 2 nuts, and 1 bolt. Use a 12mm socket to remove the bolt. It is oriented vertically and located near where the airbag connector was. Now remove the 2 12mm nuts and 3 Phillips screws. They all face towards the passenger seat. Gently remove the airbag. If it is difficult to remove, then use a scredriver to gently pry the airbag at the brackets where the screws and nuts were. Set the airbag aside with upper surface facing upwards.



You can see the kick panel hanging down in the photo above.



5. Remove the gold-colored, 10mm nut at the right end of the center section of wooden trim (shown below).



6. Release the clip at the left end of the vent assembly that attaches it to the vehicle. Gently maneuver the vent/trim assembly until it can easily be removed. Take it to a suitable work table and proceed as instructed below.



7. Remove the 2 small Phillips screws in the center of the wood trim at both the top and bottom edges. You may have to trim away some felt material.



8. Remove the 2 gold-colored and 2 black Phillips screws from the back.



Notice in the picture below that the clip between the gold-colored screws has broken off.





(continued in pt.2)

 

continued from pt.1

9. Gently remove the wooden trim and set aside. Be carefull not to lose the gold colored bolt that is between where the black Phillips screws were.







10. At this point you must decide whether or not to repair or replace the vent assembly. Because of several broken and cracked places in my vent assembly, I replaced it. I discovered that the SC center vent assembly is different for SCs depending on the passenger airbag. You can no longer get the assembly without the wood trim if you have a passenger airbag. With trim it's ~$700!


11. Reinstall in reverse order from above. Be sure the gold-colored stud is inplace before you reattch the wooden trim to the assembly. Torque airbag nuts and bolt to 15 ft-lbs. Please report any errors and omissions

 

thanks for the tips thats great...and very helpful

my 92 sc300 has a vent crack in the exact same place...is there a reason for this?

my car however doesnt have a passenger side airbag

 

Wow, what a PITA! Thanks for the detailed post! I have been meaning to change my out...guess I don't have a excuse now!. I wish they made one that wouldn't crack eventually...

 

any specific reasonn they crack?

 

I think the vents crack because of the wood trim... wood will expand when its hot... is that about correct?

 

I don't know why they crack. My feeling is that it's just a poor design, the use of wrong materials, or both.

 

I have read on other threads that the cracking is caused by the fast expansion/contraction of the vents from the initial rush of hot heater air in the winter, and/or cold air from the A/C in the summer. If so, the trick to long-lasting vents may be to initially go easy on the climate control.

Special thanks to SMARK for taking to time to initially post this, and for resurrecting the hosted pics (they had disappeared for a while, but I PMed him today and he quickly restored them).

 

wow talk about bringing a thread back from the dead. I just removed mine last week and yet to fix it. I was thinking of using a super glue or some crazy adhesive of some sort. what have you guys used?

 

I don't know what the point of all this is.. its a flaw in the car, everyone who does it, just has it re-crack in 2 weeks..

 

The reason these vents crack is from the mainly from summer Air Conditioning use.
The vent plastic sits in the summer sun for hours and gets very very hot being black plastic, you get in and want instant coolness and turn the A/C on to full cold.
The plastic goes from 150 Degrees to 40 Degrees in a very shory period of time and the plastic cracks.
The only way to prevent this is to reinforce the back of the corners of the plastic vent with epoxy or fibreglass when you replace them.
The corners always crack because that is where all the stress is from the rapid contraction of the plastic.

Laws of Physics---- Heat =Expansion------Cold = Contraction.

The reverse is true in the winter.
Car sits for hours in sub zero temp.
Driver gets in and turns heat on full blast for comfort--------Cold Plastic expands.

It is my opinion that the winter scenario is not the problem.

It is the summer scenario that causes the cracks.


Rob

 

nice job on the write up

 

inovashn
Thanks for the compliment.
I may just do a write up on the window winder failures soon.

There is a reason why the window winders break apart as well.

Will post when the next member has his windows fail,

Rob

 

Um, he was talking to SMARK, but we'll look forward to your window writeup just the same.

No need to wait - there is already an extensive discussion going on at:
https://www.clublexus.com/forums/sc-1st-gen-1992-2000/95720-window-regulator-fix-for-sc-models.html

 

Very nice write up on this project. This ought to be very helpful to a lot of people here.