Thanks to everyone who responded to my questions, looks like I found the right forum to hang out. Hopefully when I slowly figure out the MB cars I can have a DIY web page set up just like the one I have for the p-cars.

For sure I am keeping the air cooled 911, definitely not going to step over to the water cooled Porsche any time soon.

As for the "clunk" during shifting, I think everyone missed the fact that this "clunk" sound and jolt only happens when the A/C is turned on. And the car shifts flawlessly when the A/C is off.

This which makes me believe that there is a vaccum leak somewhere in the climate control system. (Itis operated completely with vaccum control, right?) My logic is since the transmission modulator is controled by vaccum (I assuming it is), that once the A/C climate control is turned on the vaccum there from the controls causes less vaccum needed to control the shifting of the transmission properly?

Everything with the A/C seem to work properly, it blow cold air and there are no abnormal noises.

Now the next step is to take a apart the climate control console and figure out where the vaccum leak is. Anyone have any instruction on how to remove the radio? Climate control system? and is there a radio security code that I need to enter once I remove the radio? (Original radio unit)

TIA

Robin