Main.TrailIndexPage | Transmission and Clutch | TransmissionClutch.Tunnel

Transmission Tunnel

This component is part of Transmission and Clutch.


Define the component. Include, if known, the german language word for the component, as well as the English or American equivalent. Show a picture, a diagram.

  • Its technical name & common name(s)
  • part # - start year & end year
  • which area it belongs to - engine, transmission, body, injection etc, link back to the relevant section


Describe, in general terms the function of this component. Meaning what is it there for and what role it plays. Describe how it works, the inside mechanism. Use diagrams to explain.


Describe common maintenance procedures, and common faults that may occur. Describe how these may be diagnosed and resolved. Again, include diagrams, photographs and explanations. Where possible, include measures, tolerances, weights etc.

  • Symptoms when it faults
  • How to test if it is faulty - what tools to use
  • How to fix / change

Link to related components where appropriate.

Old Yahoo content

The following is the content from the old Yahoo documents on the site. It needs to be structured and edited in the correct sections of the entire document. After moving particular content to its correct place in the manual, please delete it here.

For years I have had a problem with the auto transmission gear shift lever housing on the interior of the car getting hot. In the hot summer Nebraska days it is a real pain. And it really gets quite hot. I am lost as to the source of the problem. Does anyone have any ideas?

I have the same problem with my 66 230. I'm going to have the transmission fluid changed and a new filter installed to see if it helps.

I think that generally the car is a hot one. In the summer heat seems to radiate through the firewall.

During restoration of my 230 SL automatic I have found that part no. 113 680 01 75 - tunnel cover plate under transmision is missing. I tried to order this part from Mercedes Benz but I received information that it is not available. I hope somebody can give me indormation where can I find this part.

Frank says: You could try Was the car operational when you got it? I don't understand how you could run a car that didn't have that part. Also, mine has a number stamped into it, possibly the last 4 digits of the body or chassis number. If you find a used one, you may find that it needs fitting (all those 10 mm screws ...).

Thank you for the answer. The car was not running at all. I have my restoration almost finished and I cannot arrange my FIRST drive without this plate. I understand that you suggest that not every cover plate fits every car. I would be happy even to find an incorrect one and spend the time to make it fit. Until today I was sure that the w113 was a mass-manufactured model with every major part being interchangable ....

Frank says: if you look at various body parts such as under left rear edge of the hood, underneath the rear edge of the hardtop, and under the softtop cover, you will see a number stamped-in, that should correspond to the last 4 digits of your body number. This implies a certain amount of fitting; either the panel was fitted to the body, or the body shell was adjusted to fit the panel. Probably it would at most be necessary to drill open the holes to make a cover plate from another car fit your car, and auto/standard trans use the same plate. It is a fairly complex and heavy-gauge plate, so it would not be easy to fabricate.

Do you by chance know what material this tunnel plate is made of? Is it diecast or cast iron (or aluminum)? Some of my welded-on nuts are dull, I need to close them by welding and to re-drill and re-cut the threads.

The plate is stamped out of steel and has a reinforcing piece welded on. I can't remember it having any nuts; the nuts are on the body, and screws pass through holes in the plate to secure it to the body. It has an additional hole in the center that the transmission mount bolt passes through. I'll bet the center exhaust heat shield is also missing from the 230 SL that has the missing cover plate.
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