And this is my attempt to make one.

I used 5/32" 7x19 rigging wire. I was thinking of using curtain wire, but couldn't find any in house.

So as to make the markings, I slipped on some heat shrink tube and set it in place. Markings may not stay forever, but can be redone.

ADDED: As barri pointed out below, there should be a stop to limit how far cable enters pan. It seems from photos on forum that the stop should be about 6.8cm from end. The unit below is being sold on eBay and seems to have incorporated the stop. But if markings are changed as per later post, probably no need for stop.

My initial attempt below:

 

read this thread Graham
http://www.benzworld.org/forums/w210-e-class/1648383-too-much-trans-fluid.html
atmsmshr figured out that the original dipstick is actually stopped before bottoming out by those little wings. makes about a half liter difference. I think mbvis went and checked the new distances and gave them near the end of the thread.
cheers
Barri

 

Thanks for pointing that out Barri!

I just checked insertion depth with my "tool". What is interesting, is that it is exactly 35 3/4" - same as length in ATSG diagram which would mean that IF MB tool could be fully inserted, it would just reach the bottom of the pan. Probably just a coincidence.

I have now marked my "tool" at 34.5" which I got from the link. Is that the insertion depth you get with your MB tool? ADDED: Ok, forget that - better to use MBVIS measurement and make 25C marks at 21mm&32MM and 80C marks at 66mm&77mm for dipstick that will hit bottom.

I lost just under 1L when I changed the adapter/plug. I also found a little in the TCM. Prior to that dealer had set level 40k km ago and there have been no external leaks. I should hopefully have the correct amount of fluid, but made the dipstick just to cross-check.

ADDED: Checked level cold (~30C) and then after run assuming 34.5" is proper insertion length.
Cold it was in range, but after run is was only midway between cold/hot marks. I see a big problem in measuring temperature with IR gun. Surface condition makes a difference. I got 90C on pan, but I think it picks up radiant heat from exhaust. I am not sure I chose proper connection, but at upper passenger side of rad there is smaller metal line. It was at about 80C +/-.

Seeing I probably need more ATF, I might see if I can get dealer to measure level for me when I pick it up Monday.

ADDED: Changed design and added thermocouple - link here