This project is fairly straight forward… Cleaning and servicing a Kenmore model 158.1755. The 158.1755 was manufactured in Japan by the Maruzen Sewing Machine Factory. The production run for the 1755 was between 1970 and 1971. The 1755 machine is a versatile and very forgiving all metal sewing machine. Easy to thread, easy to adjust, and easy to sew. It features two built in stretch stitches, along with the standard ziz-zag and straight stitch. The number of decorative and pattern stitches expands to 14 by inserting plastic cam discs into the cam mechanism accessed by a cover plate on the top of the machine. The machine produces a very good and consistent straight stitch and a very nice satin stitch. Pattern cam stitches are very good as well.
Under the hood is an all metal gear driven sewing mechanism. The oscillating shuttle hook is also driven by a set of steel gears. All of this is driven by a powerful yet quiet 1.2 amp motor. Power is delivered to the balance wheel via a double belt reduction drive. The sewing machine’s body is cast aluminum, as is the balance wheel. The top and front cover is made out of metal. The paint is enamel. The needle plate, needle plate insert, and the bobbin cover plate are stainless steel and sized for larger hands and easy access to the bobbin area to insert the bobbin case. All in all, the 1755 is a very robust, tough, strong, powerful, and sturdy sewing machine. But none of this is “special” or “unique” to the Kenmore 158 series line-up. In fact, it is fairly common for a Kenmore and it is one of the reasons that these all metal vintage Kenmore’s are such a good value.
One of the nicest features, besides it’s ability to sew well, is Kenmores are easy to clean and maintain. This particular machine has an unknown history. It showed up with some marks from use, consisting of a few small scratches and a few paint chips on the sewing machine bed. The drive mechanism showed the typical discoloration from oil varnish buildup. The sewing mechanism turned smoothly and all of the stitch functions operated smoothly as well. But… this is not unusual for a Kenmore of this vintage.
After my initial evaluation, I decided that all this machine needed was a full cleaning and servicing. Well… if was just a matter of cosmetic cleaning and oiling, I could stop here. This machine is in store for a little more. Of course, the body of the machine will be cleaned, but he sewing mechanisms will be deep cleaned to remove all traces of old oil and grease. All of the plates, fittings, bobbin assembly, and removable little bits will be ultrasonically cleaned. The motor will be partially disassembled to polish the armature and clean the brushes. The tension assemblies, both the top assembly and the bobbin case, will be disassembled and ultrasonically cleaned. So… here is the process in pictures…
First, all of the covers, the balance wheel, the belts, and the motor is removed from the machine… This allows easier access to clean the internal mechanisms.
Disassembly of the mechanisms is really not necessary so they are cleaned in place. The only assemblies removed are the bobbin winding assembly, the top presser foot adjusting assembly, and the presser bar spring. This makes it easier get into tight places, and it is a laborious process to get all of the parts cleaned and de-greased. For me, the easiest way clean these assemblies is by using a small utility brush and a 20% solution of “Krud Kutter”. Unlike products like 409, Fantastic, Purple Power, or other similar detergents, Krud Kutter is non-toxic and environmentally safe… that means it won’t damage the finish on the sewing machine. Still, out of an abundance of caution I don’t allow any detergent to sit on the enameled surface too long, so wiping any drips or runs is important. It is also important to keep detergent from getting into the oil holes in the parts provided for routine oiling. This is easy to do by covering the oil hole with a cotton swab as the parts are being cleaned. After cleaning the assemblies in the needle bar area, the cam and drive mechanisms in the sewing machine arm, and the assemblies under the bed, these areas are sprayed with a light coat of WD-40. This displaces any lingering water and detergent, and leaves a protective film.
The next step is to clean the shuttle hook gear box and re-grease the gears… The yellow stuff is old grease and it is removed with dental picks and a small blade screw driver. After cleaning off the residue with a stiff utility brush, the gears are re-greased with Tri-Flow grease.
Did you notice how clean the bed mechanisms are? The next step is to service the motor… This only requires the motor brush and rear motor cover removal.
After reassembly and oiling, comes the disassembly and cleaning of the tension assemblies.
The next picture is important to show… it shows what can hide in the bobbin case and wreaks havoc with getting a good tension balance and/or intermittent tension problems. If you find yourself having to adjust the top tension repeatedly while sewing a project, this may be the culprit… If you think this may be your problem, and don’t want to mess with a very small screw and adjustments, just replace it… they are pretty cheap.
The small leaf spring performs the same task as the tension discs in the top tension mechanism. It is adjusted with a small screw to regulate the clamping force, or “drag” on the bobbin thread. If you look closely, you will see corrosion on the bobbin case, and crud on the leaf spring… all of it is directly in the thread path. Often overlooked, this is a very important part of servicing a sewing machine. After a soft bristle steel wire wheel, it is good as new.
The top tension parts after cleaning…
Meanwhile… all of the parts removed earlier have been ultrasonically cleaned… Then soaked in WD-40 (except the bobbin tire). A further step is taken with the bobbin winding assembly. It is soaked in 99% alcohol to remove any trace of the WD-40.
All of the part are reassembled on the machine, and attention is turned to cleaning the exterior of the machine… Not much to say here except the machine case, covers, and balance wheel are cleaned of any dirt and old oil. Kenmore enamel paint is tough and looks great when clean.
After the machine is assembled, it is lubricated with tri-flow oil, adjusted for thread balance and feed dog operation, adjusted, tested, and…. That’s it!
The result is a quiet, powerful, smooth running sewing machine that makes a stitch as good as new… and it will for another very long time.
Well, I hope you gleaned some good information and tips regarding the steps you may take to clean your Kenmore.
Let me know what you think!