1966 230SL Heater Core Replacement

[Harry]

I am well into this process and at the point where I need to disconnect the cables on top of the lever controls.  I have concluded that I need to remove the radio speaker to (hopefully) get access.  Otherwise, I don't see how you can remove the clips and loosen the cable nuts on the upper controls.  I have searched across the forum and found some good material but nothing says to remove the speaker so I am curious whether I am missing something.

For those who have done this, can you elaborate for me?  Pictures or links would also be handy.

Thanks!
Harry

[Larry & Norma]

Yes remove radio and speaker, it is a very fiddly job difficult to describe. Take photo's before
stripping down. You may find a mirror helps to see inside the speaker aperture. Ideally
remove the windscreen, probably impractical though.
Be careful not to let the clips fall behind the dash :'(

[Naj ✝︎]

Hi, Harry,

To get to the heater matrix, you will need to remove the front panel where the radio and clock fit. The glove box will have to come out to remove the clock and also some under-dash trim to get the panel off.
A little bit of extra work but the access is much better on a 230 than the later cars, once the panel if off.
I found that there was a small gap between the heater matrix brackets and the fitting points in the cabin, so that the brackets are stressed when you tighten up the retaining bolts. I used two rubber tap washers (one on each side) to fill the gap and then nyloc nuts that are just snugged up to avoid stressing the newly  soldered brackets.

Naj

[Harry]

Thanks for the response and the photos.  I can see that removing the speaker is hugely helpful on accessing the levers.  Otherwise, I do have the dash disassembled as you show.  Do you also have any photos of the dash pad?  I hope to reupholster mine while things are this far down.  I need to do some research here on the forum.  I've done some but more is in order.

Harry

[Harry]

I am to the core itself now, having successfully removed the Lever Assembly and Heater Blower/plenum.  Removal of the speaker was imperative to getting the Lever Assembly removed.  I can't imagine how you could remove the top two cable nuts without doing so.  I thought I might add some points for future reference (at this juncture in the job) to be of assistance.  For clarity, my car is a 1966 230SL.  I can tell from posted photographs that there are differences in the access through the dash dependent on year/model.
Speaker Removal
The wooden grill lifted off by carefully lifting along the front edge and working that edge up.  Mine was fastend by what appears to be two plastic coated pins that fit snugly into two receiving holes in the dash (no nuts or other fasteners). These pins were mounted on a base that was then glued to the grill.  As you're doing this, the speaker grill is increasingly interfering with the two piece of wood lying along the windshield.  My grill came out alright but I did manage to slightly chip the passenger side piece of wood trim under the windshield.  I can repair it but it might be optimal to first remove the windshield wood pieces.  I realize that is no small task in itself.
The speaker itself was easily removed by tilting the front edge up and pulling towards the seat.  It also was not securely fastened.  This may be because some pieces that would normally hold it secure by being compressed (insulating type of material) were very aged.  I'll know more when I look at it more carefully.
Heater Blower/Plenum
After removing the levers, this seemed to be a relief to remove but there were some things that are noteworthy.  As always, I carefully labelled all wires/connectors and took progressive photographs.  The plenum was removed in pieces to get to the blower unit itself.  Each windshield plenum was attached by two 10mm bolts into the top of the footwell plenum.  The footweel plenum is then completely freed by unbolting along the edge and removal of the bracket fastened on top of the tranny tunnel.  This last part unfortunately consists of an "L" bracket that bolts to the tunnel and to a point on the footwell plenum.  The bracket is fastened to the tunnel by a 10mm bolt AND NUT - so it cannot be removed solely by top access.  I had to remove an access panel on top of the tunnel so that I could get a wrench on the nut under the tunnel.  Not particularly hard but tight fit.
Lastly, I had to also remove the passenger side "end" of the footwell plenum to get it out from under the dash.  "End" refers to a piece of the plenum held on by three small screws that is curved towrds the passenger floor to direct the air in that direction.  Without removing this "end" piece, the footwell plenum kept hitting the water drain in front of the passenger side and I was concerned that if I tried to force it, I would damage the unit.
More to follow as the task proceeds.