Replacing the Body Shell Rubber Bushings on an Olympia SG1 Typewriter

Over the weekend I made a major push on beginning restoration of the Olympia SG1 standard typewriter I picked up this past month. 

One of the small issues I encountered was finding four crushed rubber bushings between the exterior typewriter shell and the main chassis at the four corners on the bottom of the machine.

View of the back corner underneath an Olympia SG1 typewriter featuring a crushed rubber washer between the body shell and the solid steel chassis of the typewriter. It look like it's less than a millimeter thick.
This black rubber bushing is so smashed you almost can’t see it above the silver screw head at the bottom of the typewriter frame. The typewriter’s foot has been removed from the vacant screw hole just to the left of the bushing screw to provide better visibility.

This is a common repair issue for the Olympia SM3 machines and one which can dramatically impair that typewriter’s functionality after several decades. I expected this would be a common enough problem, so I searched a few fora, YouTube, and some specialty  Facebook Groups to see how others had done the replacement and find the specs for the original part. Sadly none were forthcoming. Has no one written this up before? Perhaps because the issue isn’t a huge problem from a functional perspective, no one has bothered?

But when you’re doing a thorough restoration on a machine you plan to put into daily use, you go the extra mile. To that end, I thought I’d write up a few notes for those who encounter this in the future, particularly as I couldn’t find quick sources on it the way one can for the SM3. 

My crushed rubber husks (now more like a brittle, friable plastic) were approximately 16mmOD x 4mm ID x 2 mm, but I wanted to do better than guessing the appropriate replacement. Fortunately our friend Richard Polt has a downloadable .pdf copy of the Olympia Spare Parts Catalog and Price List for Standard Typewriters Model SG1 (Jan. 1, 1961 edition) from the Ames Supply Company on his website. Pulling it up very quickly provided a diagram of the appropriate part on page 12 and indicated it to be part number 34280-5x.6. Scrolling ahead to page 61, one discovers that the part is called a “spacing washer (rubber)” whose original specs are listed as 5⌀12⌀x4mm which originally listed for 11¢. On a German manufactured machine this is indicating a 5mm inner diameter, 12 mm outer diameter, and thickness of 4mm.

Mechanical diagram of the parts pertaining to the body shell of the Olympia SG1. The rubber washer part number is highlighted in yellow.

A quick spin over to the local Ace Hardware store and I was able to find a variety of Hillman rubber bushings on offer as potential replacements.

Photo of the various specifications of about a dozen rubber bushings from a display in the hardware store.

I selected Hillman part number 405784-E as the closest bushing with dimensions 1/4″ overall length; 3/16″ ID, 9/16″ major dia.; 3/8″ min. dia. and 1/8″ Hd. thickness. I picked up 4 of them for $0.95 each. Depending on availability, others might find luck ordering something of similar size and dimension from purveyors like McMaster-Carr or Grainger.

Comparison of the old bushings on the left with the new rubber bushings on the right separated by the shoulder bolts and washers in the middle.
The old (left) and the new (right).

Back at home I inserted the smaller end into the hole of the frame and screwed the shoulder bolt and washer back in to hold the frame onto the typewriter chassis. It seemed an excellent fit and this part of the machine should be in good shape for the next few decades. 

If this is the only repair you’re making to your machine, I suggest you replace each one, one-at-a-time in turn. This will prevent you from needing to take apart more of the machine or removing the entire body shell to get them on and will speed up the replacement process. If you’re doing it as a larger restoration, then just install them when you re-attach the body shell. For me, loosely attaching the two rear ones followed by the two at the front and then tightening/adjusting them all seemed to be the easier way to go.

If you’re restoring your own SG1, I hope these details make your work and research a bit quicker and easier.