Cars / Garage Life / Sweet Builds / Tech

Project 280 SLeeper Part 2: Our 1970 Mercedes 280SL Gets Suspended

The plan for our 1970 Mercedes Benz 280SL calls for a V8 swap and a color change from a boring and unhealthy Tobacco Brown to a much more soothing Blue Gray Metallic and the interior color from brown to red. The parts are back from their various coaters, platers, and blessers… and we are putting Humpty back together again.

 

Suspension

Up front the 280SL uses upper and lower control arms with a coil spring. A sway bar helps weight transfer from side to side. Kingpins link the upper and lower outer trunnions to the spindle assembly. Bilstein sport shocks handle the dampening. This is a standard front suspension layout for the time.

Out back is a different story. An independent single-joint, low-pivot swing rear-axle is used with a transverse compensator spring in place of a sway bar. Mercedes-Benz Technical Director Prof. Fritz Nallinger explained the design, “It was our aim to create a very safe and fast sports car with high performance, which despite its sports characteristics, provides a very high degree of traveling comfort.” Job well done professor!

All pieces were disassembled, cleaned and inspected before refinishing. The differential was serviced with new bearings and the ring and pinion gears were in excellent condition so no work was needed there. The brake calipers were also cleaned and disassembled. We refinished the calipers in the original gold zinc plating prior to rebuilding them.

We chose the factory option Bundt style alloy wheels to replace the steel wheels and hubcaps. The steering box was getting worn so we replaced it with a rebuilt unit from our friends at Pelican Parts.

Interior

We chose upholstery code 243 red for the leather interior of our 280SL. It shows really well with the DB 906 light blue metallic paint. Sound deadening was placed on the floor and center tunnel to help quite road noise. Because we’re using the four-speed transmission and shifter from the donor 300SEL we needed to make some modifications, which placed the gearshift lever on top of the tunnel and slightly to the right. Our solution to cover the shifter was to make an aluminum cap that sits on top of the tunnel. Once covered with carpet the change is hardly noticeable.

We also altered the seating and some of the controls to better accommodate the owners body type. The seat backs and bases were narrowed up and the seat bases lowered closer to the floor to better place the driver inside the car. We also modified the seat frame and padding to help increase the legroom and provide better lumbar and thigh support.

 

 

 

 

 

 

 

A special Nardi steering wheel was added with a custom machined adapter to provide the ideal reach. We also reshaped the position of the shift lever to bring it closer to the steering wheel. Lowered door panel armrests complete the changes to the driving position, making it a perfect fit.

Wiring

For the assembly team the most difficult task in a full restoration is dealing with the wiring. It takes time to identify every connector for every gauge, switch, and electrical component before removing it from the car. And once it’s out you still need to service it. Many connectors needed to have their plastic housings removed in order to pull them through small holes in bulkheads or the firewall. Pulling wire is a slow methodical process. You need to remember that it all needs to go back in some day!

Stay tuned for Part 3.

Have fun in your garage!

 


One Comment

  1. Justin Bono says:

    I love what you are doing to the SL. I’m doing the same thing to mine. Glad to see someone else with a desire to make things better than they are. A V8 and a Pagoda, the perfect combination!

    Are there going to be more parts to this build? If so when do you expect to post them?

    Best Regards,
    Justin Bono.

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