Author Topic: Soliciting Advice for Heater Air Door Repair  (Read 2486 times)

DavidAPease

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Soliciting Advice for Heater Air Door Repair
« on: May 27, 2021, 23:56:07 »
Hi, everyone,

I am in the process of replacing the left (driver) heater air door on my 230SL.  (This door is operated by the lower-left heater control "slide", and in turn drives the heater core valve arm.)  The door pivots on pins held in place by plastic inserts in two vertical supports.  One of these supports needs to be removed in order to remove or replace the door.  The support in the center of the car (which has inserts for both the left and right air doors) does not appear to be removable.  The support on the left is an L-shaped bracket held in place by a nut.  The nut is screwed to a bolt (or bolt-like thing) that rises vertically from the surface of the car body (the head of this "bolt" is not visible, nor can I find any way that it is accessible).  I presume that the bolt is welded or otherwise permanently attached to the body, since otherwise removing the nut and bracket would allow it to fall out into the inaccessible depths of the body.

I assumed (always a bad idea) that removing this left support would be a five-minute job.  Unfortunately, the nut was quite frozen in place.  After two afternoons of increasingly aggressive tools interspersed with shots of PB Blaster, I finally got a small vise grip attached to the nut and got it to move.  I noticed that the bracket moved with the nut, but didn't mind that, as long as both came off.  After some revolutions of the nut, I noticed that neither the nut nor the bracket seemed to be moving any further up the bolt.  Careful inspection with a flashlight revealed that the bolt itself was turning along with the nut and bracket.  This pretty much makes it impossible to remove the nut.

In the photo below you can see the air door opening on the right, and the bolt, bracket, and nut in the center.  The bracket has been rotated about 180 degrees from where it belongs.  It appears to me that, short of trying to cut the whole mess off, my chances of removing the nut and bracket are now zero. 

My only thought is to fashion a new bracket (probably not too difficult) and try to attach it to the area just to the right of the current assembly.  Before I proceed, I am asking for advice on the following questions:
  • What would be the best way to attach a new bracket to the body?  Something like a self-tapping screw, the sheet metal equivalent of a molly bolt, JB Weld?
  • Does anyone know how to access the "head" of the bolt from below?
  • Does anyone have any other thoughts on how I might rescue and reuse the current parts?
  • Anything else I should have thought of and asked, but didn't?

Thanks for any help!

               -David
-David Pease
 '66 230SL (Originally sold in Paris)

Sead

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Re: Soliciting Advice for Heater Air Door Repair
« Reply #1 on: May 28, 2021, 08:50:42 »
this bolt is not welded to the body. it is normal "m6 x smthing" bolt with hex head which u can access from below.
1964 230SL

DavidAPease

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Re: Soliciting Advice for Heater Air Door Repair
« Reply #2 on: May 28, 2021, 19:22:11 »
Wow, thank you, Sead!  I guess I didn't poke around underneath the car enough to find it.   :-[

                -David
-David Pease
 '66 230SL (Originally sold in Paris)

rmunson

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Re: Soliciting Advice for Heater Air Door Repair
« Reply #3 on: June 24, 2022, 19:58:53 »
Where is the bolt under the car which holds the heater flap bracket?  I cannot tell from the photo provided by Sead.

Thanks
Russ
R.Munson
1969 280SL

DavidAPease

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Re: Soliciting Advice for Heater Air Door Repair
« Reply #4 on: June 24, 2022, 20:42:06 »
Russ,

The bolt in Sead's third photo is a real b!tch to reach.  On my LHD car, it is up somewhere invisible and barely reachable in the bowels of the dash (inside the car), more or less above the gas pedal. I found it only by having someone rotate the nut from above then feeling around for something moving.  As I remarked in another thread, it made removing the instruments look easy.

       -David
-David Pease
 '66 230SL (Originally sold in Paris)