Basic Maintenance for Class 35800 Machines

Union Special's Class 35800 three-needle, high-throw, feed-off-the-arm machine was introduced to the sewing industry in the late 1920's.  Yet, it's not unusual to find many of these machines still sewing reliably, day in and day out, after 70 years of operation.  The utility of this basic design has kept this machine Class the best choice for many triple stitch felling operations on medium to extra heavy weight materials.

Maintaining this degree of reliability requires basic maintenance be conducted on a regularly scheduled basis and a quality lubricant be used at each oil change.

Following are the recommended steps for performing basic, preventative maintenance on all 35800 felling machines.

Whenever oil is changed, it is important to use Union Special Spec. 175 oil having the following characteristics:

Viscosity at 100F = 90-125

Flash point (minimum) = 350F

Color A.S.T.M (maximum) = 1

Viscosity index (minimum) = 85

Aniline No. = 175-225

Copper corrosion (maximum) = 1A

Neutralization No. (maximum) = 0.10M

To keep wear and contamination to a minimum, oil should be changed every six months or every 2000 hours of operation, whichever comes first.  Intervals of oil change should never exceed 12 months.

1. To drain the oil, remove the oil drain plug and oil seal ring from the lower cylinder arm, Figure 1.  Remove the filter screen from the oil drain plug, Figure 2.  and clean these parts. (For later machines with the new filter screen on the lower cylinder arm, refer to the 36200 maintenance article (Figure 4).  Also, remove the second drain plug and gasket from the upper arm to completely drain the oil from this part of the machine,  Figure 3.  When the oil is completely drained, reinstall both drain plugs along with their gaskets and filter screens.  Fill both oil reservoirs, Figure 4 & 5, to the top lines of the respective sight gauges, Figure 6 & 7.  Note:  When changing oil be sure to replace it with Spec. 175.  To use other than a specified oil may cause damage to the machine and void any warranties.  
   

2. Clean lint and any other foreign material from the looper area,  Figure 8, and inspect the loopers for nicks, burrs or other possible damage.  Also inspect the needle guard for excessive wear and repair or replace any defective parts as required.
   

3. Check the remainder of the sewing area for worn or bent parts and repair or replace as required.  Be especially critical of needles, feed dogs, throat plates and presser foot.  NOTE:  Be sure to use geniune Union Special parts to ensure fit and performance.
   

4. With the motor turned off, depress the treadle.  Using the hand wheel on the motor, turn it in the operating direction of the machine and check for binds.  Remove the pulley guard and check the pulley for end shake.  If end shake is detected, it can be removed by loosening the two set screws in the pulley groove, Figure 9.  and moving the pulley toward the bearing housing.  When this side to side movement is eliminated, retighten the two set screws.
   

5. Check all of the other thread handling parts, including thread eyelets and tension disks for wear, burrs and damage,  Figure 10
   

6. Run the machine and check for proper oil flow from the oil pump.  This is viewed on the machine top cover oil flow sight gauge as shown earlier in, Figure 6 NE