[T3] Thermostat Air Flap

[Jim Adney]

On 24 Jun 2011 at 13:57, J. Jonik wrote:

> I found, to my surprise, that my defunct 73 indeed had a thermostat in
> it. So, to replace the one that was fully extended and said to be
> broken, I took it out and put it in the 71 (w/ 72 engine).   It took
> up about 3/4 or more of the space in the bracket. 

Sounds good.

> But, then I noticed that the one I started with had 15 rings.  The one
> that I got from the 72  that's in the car now, has 10 rings.    What's
> that difference about?  Maybe the 15 ring was isn't broken but is just
> for some other car or other assembly? 

It's the right one. Yes, they came in different styles. I'm not sure 
if that was a difference in makers or just a difference in 
manufacturing date. If you wire brush the bottom plate there should 
be a temp, which I think is 65 C, on each one. IIRC, some later FI 
beetles used one which was a little hotter, but you're not likely to 
run into one of those.

> In any case, it's still not right.  I cannot adjust the flap rod to
> its pivot so that the flap is only open that fraction of an inch.  
> It's open more than 3/4s of the way...and the flap rod is attached to
> the pivot at the last tippy end of the rod.  No more room to adjust. 

Flap rod connected to the flap hole closest to the flap shaft? Spring 
connected to the hole farthest from the shaft?

Unbolt the thermostat and let the spring pull it all the way to the 
top of its enclosure, adjust the flaps so they are horizontal, no 
higher. Then when you bolt the thermostat down, how much gap is 
there?  

If you adjust it so that the flaps open past horizontal, the closed 
(cold) gap will be larger than desired. You don't want the flaps to 
go past horizontal.

Also, have you noticed that the hole in the bottom of the thermostat 
bracket has 2 flats so that the thermostat will drop in there? If it 
hasn't dropped in, then the gap will be larger than desired.

Any chance the vertical rod has some extra bends in it, that might be 
shortening its effective length?

> So, there it is all together...but apparently not functional...unless
> really cold weather will shrink the thermostat down about 3/4 s of an
> inch. 

Really cold weather might make them shrink a tiny bit more, but I 
wouldn't expect it to be significant.

>  The spring had to be shortened just a bit to keep some tension...and
> it's hooked up right...snug on its hook up-spot, snugged in next to
> that "broken" notch in the bracket. 

Sounds fine.

>   I don't think I have the assembly meant for this car.   Are there
> pics of different assemblies, and mention of what car they're
> for...and what the rod and thermostat measurements are?

Nothing else looks remotely like the Type 3 linkage. There was an 
early version, for single port heads, for which the flaps rod had 2 
bends in it. The dual port pull rod is straight. Everything else is 
the same for all Type 3s. It sounds like you've got the right parts.

BTW, when you mounted the bracket on those 2 top center head studs, 
you did it with the washers UNDER the bracket, Right?

(washers/bracket/nuts) torque to spec.

-- 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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