'66 230sl auto gearbox

[mylo]

Hello.
My name is Miles and I'm a newbie here. I based in Essex, UK.
I have a 1966 230sl auto.
when I put in reverse the engine tends to stall if the revs are too low. I understand that i need a replacement switch on the gearbox. I was told this was called a compensator switch.
My questions are
i) Is that correct name for it?
ii) Are they readily available in the UK?
iii) Is it the same part for forward gears and reverse? I assume there are 2?
iv) how difficult are they to replace?
Thanks in advance for any assistance.

[Larry & Norma]

Sounds to me like the constant speed solenoid is not doing it's job.
This could well be due to the reverse pressure switch not working.
There is a lot of info on this site just need to search it out.

[stickandrudderman]

If it turns out that you need a new hydrualic switch I'm afraid they are NLA, you'll have to find second hand ones and that's not easy.
i am currently working on sourcing a replacement from outside the MB network.

[twistedtree]

It's well worth some careful diagnostics to be certain it's actually the pressure switch that's at fault.  I presume there is no problem in forward gear, just reverse?  The wires to the pressure switches are kind of exposed and the connections subject to damage.  A test light and jumper wire can be your best friend.  It might even be worth swapping the switches to confirm the problem follows the switch.