What size washers did you use? And what's the clearance between the line space lever and ribbon cover - is it just touching, or digging into the cover? There's normally a large gap between the two on an SM3, unlike other machines that have a remarkably small gap, so it sounds like either the ribbon cover isn't properly seated (unlikely, I know), or possibly the line space lever - or its mounting bracket - is bent. 

Did this work?

NDW76 wrote:

The washers I used were 1 mm in thickness, maybe I need to stack them up.

That's pretty thin, probably as thin as the squished/deteriorated washers you replaced. The ones that I always use on SM machines are 4 mm thick and seem to work fine. However, this doesn't address the line space lever. It seems from your photo that there is ample clearance between the lever and the ribbon cover, so at what point to the two come in contact with each other?

An SM4 that I fixed in the same way did exactly the same thng; the return lever only touched the case when moved to the right.  New washers cured everything, but they were much thicker than 1mm: I used cheap tap washers from the local hardware shop, which were about 3 or 4mm thick.
PS, I don't think the lever is bent, from your pix, you just need thicker washers as far as I can tell.

Last edited by beak (28-9-2014 20:16:03)

Gosh I'd forgotten all about this when I went to use my newly purchased SM3. I'm making a note to *always* check the grommets/gaskets/washers on the feet before using a new SM3. :-)