Mercedes-Benz Ponton Spare Tire Wheel Well

Wallace Wheeler / Dallas, Texas / 1960 220SE coupé (W128)

During the trunk restoration of my 1960 220SE coupe, I discovered a date code on the seal strip that was attached to the left spare tire well cover when the cover was removed. It read February 1959, which of course led me to believe that it was original to the car (see Photo 1 – 220SE seal).

I thought it odd that Mercedes would have a seal strip on the cover. I asked a local enthusiast about the seal and he said his 190SL had no such seal (see Photo 2 – 190SL). That made me want to dive in, and see what other Pontons used as a cover. Interesting that such an obscure and seemingly insignificant part would have several versions.

What I found from many local examples and a small survey on the International Ponton Owners Group (IPOG) forum is the following.

  • The SE (W128) coupes, cabriolets, and sedans all had a seal strip attached to the left spare tire well cover (see Photo 5 – 1960 220SE). The S (W180), and other non-injected cars did not have the seal strip. (see Photo 3 – 1959 220S). These are both un-restored cars.
  • The SE cars with the seal strip on the cover also had different straps attached to the board, and were screwed to the trunk pan. The non-injected cars have shorter straps, and are simply laid on top of the trunk pan held down by gravity, and the rubber mat. The 220S, and 190SL are a similar design (see Photo 4 – 1959 220S strap).
  • My 1960 SE used Masonite as the material for the board. The original material was plywood, and was switched to Masonite sometime in the 1959 model year. This is not dependent on whether it is an injected or non-injected car.
  • The 190SL and SE covers had (two) rivets securing the straps to the board (see Photo 6 – 220SE strap). Others had just one (see Photo 4 – 1959 220S strap).

The seal strip attached with both adhesive and staples. A copper staple can be seen toward the bottom of Photo 1 – 220SE seal. The seal strip profile is a “T” shape with a round “O-ring” at the end of the T similar to fender welting. It is a soft foam material. There are (four) sheet screws that secure the SE board to the trunk floor on the right side and top and bottom. The left side used open-ended straps welded to the trunk floor that the board’s straps slid into. No screws are used on this side (see Photo 7 – 220SE left strap).

My theory as to why the injected cars had a seal strip attached to the well cover is because of what is contained in the left well. There are numerous holes with grommets for electrical wires that penetrate the through the well. And more importantly, the fuel line from the pump to the main supply line also passes through the well. Because of this, I believe Mercedes felt it necessary to seal this are off from the trunk and therefore the cabin space. The screws compressed the T seal to assure a snug fit.

Table 1. Examples of Mercedes-Benz Ponton Spare Tire Wheel Wells

Photo 1. 220SE seal

Photo 2. 190SL

Photo 3. 1959 220S

Photo 4. 1959 220S strap

Photo 5. 1960 220SE

Photo 6. 220SE strap

Photo 7. 220SE left strap
It's Never The End.

Created: August 2, 2022 / Jeff Miller
Last Update: August 03, 2022

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