Kenmore 158 tension assembly

I promised a reader that I would post a tutorial about the Kenmore 158 tension assembly.  As best as I can tell, the 158.1701 (the assembly in question) looks the same or similar to this one.

Oh my, I had no idea how dirty it was.  This is from a 158.1803.

The first thing to do is take the whole kitnkaboodle out of the machine.
Loosen the set screw but don't take the screw out.  It is tiny and you might lose it.  It will release the assembly without coming all the way out.

Next remove the hex screw from the face of the tension assembly

The indicator ring will come out as well

Then you will see this

You will have to pry this out.  You can see that when you replace it, it will only fit ONE way onto the stud.

 Next you will see the wavy washer.

This should fall right out when you flip the assembly over to get this:

Pull this off and take note of the notch on the inside. (I am not the first person to take this tension assembly apart)
 This is what you get next.  The washer is quite tight and the stop washer is even tighter.

To get to the check spring you have to loosen the set screw.

You have to remove the washer and the stop washer next.  Or you could do this before you release the check spring.  Might be easier.  Check out the position of the stop washer tab.  You want it like this when you re-assemble

The washer comes off readily.  Pry the stop washer off gently.  You then get this.  The cogged "nut" willscrew off easily.  Then take off the spring and the tension release pin stop washer.

Note the position of the "nibs" (red arrow) on the tension release pin stop washer.  Don't put it in backwards.  It won't work.  Ask me how I know.

Tension release pin

Now I admit, I did not take this whole thing apart here.  I just spread things out a bit so that you can see how they go.  There are three tension discs.  One is flat.  The other two are concave.  Make sure that the concave discs "kiss" the flat one between eachother with the concave sides facing the flat discs.  I think that you can see this here.  If your machine does not accept a twin needle you will only have two discs and they should "kiss' eachother with the concave sides in.

A and E  are the outer two discs.

If you want to change the amount of "spring" in the check spring, you must move it one way or the other in the stud.  The short end of the spring fits into one of the slots in the stud. Can't see it so well here.  Sorry.

You want things position about like this before you put the casing back on over the check spring
If it doesn't work quite the way you like it, fiddle with it.  Move the check spring tail one "notch" on the stud and see what happens.

  Replace the casing making sure that you line it up with the tab on the back of the disc

And make sure that the check spring sits in the indentation in the front of the disc.

Make sure that you tighten the set screw adequately.  Otherwise the whole assembly will twist and you will be very sad.    It means starting over, basically.

Put the tension release pin in next.  It will really only go in one way.  The head is the part that comes into contact with the tension release pin washer which goes on next

Next put the spring in

Then the cogged screw.  Just get it started.

 The Stop washer goes next.  It is snug.  Don't force it.  It must go all the way to the threads.  The little tab should line up at the top and should match one of the cogs on the screw.

Next comes the little washer and then the numbered dial.

 When you put the numbered dial on, be sure that little tab on the inside is positioned to the RIGHT of the stop washer tab. It won't twist far enough otherwise.

 Then comes the wavy washer, the tabbed washer and the indicator ring

The tabbed washer sits on top of the wavy washer snugly.  Be sure it is positioned firmly.  It only goes one way.  Lucky us

Next put on the indicator ring.  It has to fit one way or the other.  The tabs on the washer must fitin the indentations on the ring.  Line up the white mark as close to zero as you can.(PS the white mark is on the opposite side of the indentations)

Replace the screw and tighten.

When replacing the tension assembly on the machine you will need the ring that goes between the tension assembly and the machine.  It has a serrated notch where a pin from the tension assembly fits

Put the whole assembly back in the machine, tighten the set screw and stitch it in.  WHEW
I marked the set screw scar so that I could re- align it.  You can see that I have had the assembly out a couple of times during this process today.  New set screw scars.

I suppose I could have put that white indicator on the top.  This project was a bit of a challenge.  I don't think it matters where it is.