Saturday, September 10, 2011

How to service and clean a Singer 66..tension assembly

 Taking the tension assembly a part is often unnecessary.  All the experts will tell you this.  I still tend to do it.  I like getting these parts really clean and I don’t find it all that difficult.  Especially on these old  machines.  I have not taken the tension apart on the 401A   nor any of my 301s.  I have cleaned and disassembled many numbered straight stitch Singer tension assemblies.  I found great instructions on the Yahoo groups.

 That gooey looking hole just to the right of the tension assembly is a set screw, believe it or not.  You definitely do not want to bugger this one up.  I squirted some LW in there and let it sit for a long time before I even attempted to loosen it.  I even took extra care to determine EXACTLY which bit fit perfectly in that screw.  Ever so carefully I loosened it.  I did take it out to clean but I put it right back before I lost it.  Whew.  Imagine trying to find that tiny thing on the floor of my shop. 
Next, I loosened the thumb nut and removed it.  I took this photo to show the individual parts of the tension assembly
Tension Washer
Tension Spring
Tension Discs

This activity may be verboten, but I was very gentle and I did not force anything.  The tension assembly was pretty stuck and just a bit of extra torque helped me loosen it enough to remove it.  This does not screw in.  The tension assembly is merely placed in this opening and the set screw holds it in place.

It is no wonder that this assembly was so stuck.  I did apply LW to help.   No damage was done to the threaded part despite my threatening it with a screw driver.   Note the tension release pin protruding from the left of the assembly. It belongs inside, but I wanted you to see it.  Don't lose this.  You will be very sad if you do. 
 All cleaned up and back together again.  Check out that needle bar.  OOOO LA LA


  1. Your photos are great! I wish I had seen your blog before I rehabilitated my 1919 Singer 66-1!I see your thread take up spring was in good shape, so you didn't need to replace it. Mine was bent beyond recognition, so I had to replace it! Also, my tension was not released when the presser foot was lifted (My tension assembly had parts put on in the wrong way).

    Steps to replace thread take up screw:
    1. Do not remove set screw on the side yet.
    2. Remove thumb nut, spring, tension release washer, and two tension discs.
    3. Put thumb nut back on post, screwing it on enough to insert blade of screwdriver as in "verboten" photo. This prevents the two parts of the rod from twisting or separating.
    4. Unscrew rod from assembly. Remove thread take up spring.
    5. Now loosen set screw, remove assembly, & clean as per your excellent instructions!
    6. Reinsert clean tension unit in machine, with open space from 7 o'clock to 11 o'clock. Secure with set screw.
    6. Put new spring on rod, screw rod into unit with take up spring at about 1 o'clock (use thumb nut trick again to tighten).
    7. Position thread take up spring into the open space (between 7-11 o'clock) before adding the thread discs, the tension release washer, the tension spring, and the thumb nut screw.

    I like your reminder to make sure you don't lose the tension release pin! Make sure when your tension unit is assembled and in place, that the tension release pin is sticking out from the unit just a bit! If it doesn't stick out, the tension won't release when the presser foot is lifted.

    I have since cleaned & oiled my entire machine, replaced the treadle belt, replaced the bobbin rubber, replaced the broken bobbin cover plate holder (spring), replaced the missing bobbin cover plate, and replaced the missing throat plate. I kept the original back attachment and found all the back clamp feet & accessories. Now my treadle machine sews perfect stitches and the only sound is from the treadle! You just can't find quality like that in new machines!!!

    When I attempted the rehab, I wasn't nervous because the machine was unusable. It wasn't usable when I bought the treadle stand to use as a sewing table for another machine 25 years ago! I also have a Singer 15-91, that I got from my mother, and a Singer 99 so I was comfortable with working on a vintage Singer.

    I truly admire your vast experience will so many different models! Do you keep them all, or do you sell some after they are rescued? I have 6 machines, and 2 sergers. I keep them set up to do different kinds of sewing.

    1. Thanks! My vast experience is all of two years!!!!

  2. Thanks so much. Your step-by-step photos gave me the courage and the knnowledge to get my grandmother's machine up and running!

  3. I have just purchases a 1919 singer and am looking for a replacement cable for the foot peddle, any recommended suppliers? Thanks!

  4. Thank you so very, very much for this post. I just now got my tension assembly out of my 1922 Singer 66 (as in, I'm typing with bits of brown gunk under my fingernails because I haven't yet thoroughly washed my hands). It's been a long 6 days of dripping on Liquid Wrench, tapping the end of the screw driver, and waiting so terribly patiently. And when the set screw was finally loose, the assembly still wouldn't budge, and I remembered this post, and very, very carefully used my screwdriver to rotate it back and forth until I'd managed to wiggle it out of the machine head. I would say mind is even dirtier than yours (I even had to let a drip of Liquid Wrench soak in overnight in order to pry the rear tension plate free), but it's out now and will be clean soon! Thanks so much for the detailed photos that gave me the courage and knowledge to make this happen.

  5. When removing the stud in the center of the tension, it is best to leave the thumbnut on and out towards the end of the threaded part. That way, it won't spread the stud apart and risk deforming or breaking it. ;-)

  6. OMG this blog is the best. It has greatly inspired me to clean/restore my Singer 66. Thank you also for such clear pictures.