Hello all,
The top heat shield in front of the bulkhead is held (in part) by two large nuts that screw into studs sticking out of the body.
One of these snapped flush and I had to drill and tap to put a length of threaded rod to fix this mess.
I was surprised when I drilled the snapped bugger to easily get through into a void behind there.
But what is behind there? I am worried I may have opened a new can of worms, a portal to a whole new world of trouble…
Thank you.
E
What studs exactly, do you have a picture? I’d think it must be the heater plenum, so probably no worries here. Possibly depending on where you drilled…
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Eric,
Right on the other side of the firewall is the major climate control assembly containing the heater matrix and air conditioning evaporator. Both are fragile components housed inside a sheet metal box. Those two studs and large nuts hold it into place.
Paul
Thank you Paul. I suppose I would have to see what things look like exactly from the other side to evaluate the possible risk I created…
I don’t suppose the space behind the bolts would be full of coolant or be under pressure right? The bolts are just holding the box right?
I see from parts catalogues that the one on the left side of the car is in front of the heater matrix and the evaporator assembly.
The one I drilled through is the one on the right side of the car. I see nothing obviously present behind there… Still investigating.
I think I got it. This bolt helps hold in place the casing of the whole HVAC, but nothing vital within a few millimeters behind it. Hopefully my hack will still hold the casing… 
Eric,
Yes, that is correct. If you didn’t drill very deep then it is unlikely that you hit anything vital.
Attached is a picture of that dash area taken from inside my former 1987 XJ6 parts car that I completely stripped before having it towed away. I circled in red the two holes in the firewall where those two studs penetrate through and where those two nuts attach. This way you can see what is on the other side. I will take a picture of one of those climate control assemblies that I removed from my parts cars and send that tomorrow so you can see what that looks like.
Paul
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This is super helpful, thank you!
Eric,
Attached is a picture of a climate control assembly that I removed from one of my Series III XJ6 parts cars with those two studs circled in red. The evaporator is at the front of that box. If you did not drill very deep into the box then it is unlikely that you damaged anything. A vacuum check of the evaporator will reveal if it has any leaks.
Paul
I think you are safe Eric.
As you can see in the diagram, the evaporator is further back and the heater matrix is behind it away from the bulkhead.
As long as the threaded rod is short enough and threads in to the box, so it keeps it in place, all is well.
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That’s the crucial point, Eric - unless your replaced stud is actually screwed into the HVAC casing it’s only held by one stud…
Frank
sj6 85 Sov Europe (UK/NZ)
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Thank you all for this. All good.
