Typewriter Talk / Olympia SM-4 flying carriage

**Posted by Mosa** 25-10-2025 02:38:51

Hello,

When I return the carriage on my SM-4, it does not stay. Instead as soon as I let go of the carriage, the drawstring does its job and recoils, pulling it back to the end. Fully depressing a letter or the spacebar holds the carriage. But let that letter go and the carriage again flies to the end.

I'm wondering if it's the escapement. My research seems to point to the 'loose dog' and/or the backlash parl not engaging properly. Does this sound to anyone like a good direction? Or best practice to get to that spot. Also, is there an exploded diagram of the SM4?

I've not worked on typewriters before, but I ground-up rebuilt my South Bend metal lathe and drill press. I'm interested to fix this. Just wondering if anyone has experience to share.

Thanks so much,
Mosa

**Posted by thetypewriterman** 25-10-2025 03:55:18

It is most likely the loose dog on the escapement. Hopefully it is just seized on its pivot. To access the escapement properly, you will have to park the drawband (there is a little hook in the carriage bed if you look carefully) and remove the carriage from its rails. If you can possibly avoid doing this, you will save yourself a lot of trouble trying to get the carriage bearings back into position afterwards. Instead, try turning the machine upside down on a piece of carpet or similar, and working from underneath with a powerful torch (or flashlight if you are in America ) Lubricate the escapement with sewing machine oil and see if you can make the loose dog move. If it is actually broken (unlikely) then you have real trouble !

**Posted by Mosa** 25-10-2025 10:49:18

Thank you so much for the advice and clear direction! I will report back. Cheers!!

**Posted by Pete E.** 25-10-2025 16:32:21

Mosa,

I had this issue for 3 machines in my collection. I used liberal amounts of denatured alcohol and compressed air blow-outs...repeated 2-3 times until the escapement assembly was "whistle clean". Problem went away. Added a drop or so of light machine oil after the clean-ups.
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**Posted by Mosa** 25-10-2025 21:59:01

Thank you so much for both of your replies. I had looked a the underside a bit and tried some things, but your suggestions really got me to sit and stare at the area for about ten solid minutes, poking with a small screwdriver, acquainting myself with the crazy amount of mechanism in there. However, nothing seemed stuck. However, a screw/nut combo was loose. I couldn't see what it was holding but I tightened it up and my typewriter is working. So hooray! I'm struggling to add photos to this thread. But, thank you so much!!

One thing, in my quest before asking anything I made a rookie mistake. I loosened the four screws holding the rack on the underside of the carriage that engages with the escapement. I moved it and now when I return the carriage, it feels like it's scraping/not as buttery smooth as it was. Is there a proper way to adjust that rack? I can't seem to get it to be better than meh.
Again, I appreciate all the help.

**Posted by Mosa** 26-10-2025 11:44:22

Well, after fiddling with the escapement rack for ten minutes, I think the whole thing flows smoothly and I consider it good. Job done. Funny, working on this is a good reminder that I can fix things on my own with guidance, not rely on someone else to always fix things. Sure, there are specialists who are amazing, but it's good to get under the hood of a mechanical thing to ascertain the issue, maybe try to fix it yourself, maybe stretch abilities and limits. Thanks again to thetypewriterman and Pete E for your gracious help.

**Posted by Pete E.** 26-10-2025 14:11:40

Mosa,

Glad to see you got your machine back in order.

I, too. have a SM-4...mine made in 1960.

It is wonderful to type and I think it was used very little in its life. Deep cleaning, bit of a light oiling, and a new ribbon was all it needed.

The case got a re-paint by me.

I am a DIY fellow, as well, when it comes to typewriters. I have 75 of them and only one I sent to a professional repair shop...as I knew I was above my pay-grade with what work it needed.
.
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**Posted by Mosa** 29-10-2025 23:26:46

That's a beauty. 75 typewriters! Major jealousy. It's super fun to work on these and get them running. I'm a bit worried I'll never stop. ;) Thanks again for all of your help.