M and MG Class Machines Maintenance

LUBRICATION

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1) General: The lubrication system is entirely automatic, feeding oil to all bearing surfaces without the use of wicks. The path of the oil as it circulates through the machine is described as follows: Two Oil Pump Plungers are operated from eccentric grooves in the main shafts. The upper shaft pump draws oil from the main reservoir and forces it through the Oil Bubbler Pipe to the Oil Bubbler Pipe Cap. The oil then drains down through holes to the Upper Shaft Oil Collector and the correct amount of oil is fed into the Upper Shaft Assembly. Inside the Upper Shaft the oil is distributed through several successive oil holes and grooves to the bearing surfaces of the main shafts on the left end of the machine, the Needle Carrier Assembly, the Upper Cutter Carrier Assembly, and the Feed Mechanism. Some of the oil not fed into the Upper Shaft is forced along the outside of the Upper Shaft, down the face of the Cam Boss, and through holes in the Main Cams to lubricate the Cam Rolls and the Frame Cap bearings. The Needle Bearing for the Lower Shaft is oiled from the overflow oil from the lower shaft pump. All the oil in the machine drains down through the Oil Filter into the Oil Filter Support and is pumped from this support by the lower shaft pump back into the oil reservoir.

Note: A special oiling Frame M-1-A-11 (MG) or M-1-5 (M) is available on request for high needle time operations. This frame provides additional oil to the feed mechanism.

2) Oil is filled through a hole under the Cap Screw of the Oil Filler Assembly into the main reservoir. About 8 ounces of a high grade turbine oil is recommended. (Refer to the Oil List page 24) To drain the oil, remove the machine from the Machine Mounting Assembly and extend the hand wheel end of the machine over the end of the table. After providing a means of catching the oil, unscrew the Oil Drain Screw(#11 3/8) several turns.

3) The following precautions are recommended:

A.	Never allow the oil level to go below the “E” line on the Oil Gage.
B.	Occasionally clean the lint around the Feed Dogs and from behind the Dust Shield and Upper Fabric Guard. (Do Not Use Compressed Air)
C.	Daily clean the lint from the drain slots around the L.C. Holder Support Assembly.
D.	Clean the Oil Filter about once a year (See Below). Replace filter after four cleanings.
E.	Clean screen on the Oil Filler Assembly if filling the machine becomes difficult (See Below).

CLEANING OIL FILTER

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4) To clean the Oil Filter remove the three screws (#83 3/16) in the Oil Filter Support and lift the machine from this support; remove the Oil Filter and clean with compressed air or solvent. When using compressed air to clean the filter, blow the air in the reverse direction of the oil flow - from bottom to the top of the Oil Filter. For best results remove and replace the three gaskets on the Oil Filter Support. (O.F. Gasket M-275-2, O.F.S. Gasket M-275-1, and O.F.S. Line Gasket M-275-3) Carefully locate the new gaskets in their proper positions, and install the cleaned filter (flat side down). Lower the machine straight down onto the Oil Filter Support Assembly, being careful not to disturb the alignment of the gaskets. Install and tighten the three screws (#83 3/16).

5) To clean the screen on the Oil Filler Assembly: unscrew the entire assembly from the machine, remove the cap screw, and clean the filler screen with compressed air or solvent.

RECOMMENDED OILS
REPRESENTATIVE LIST OF OILS FOR MERROW MACHINES*

Class MG (Green), Classes A and 60, Crochet (Black Obsolete)
Merrow Recommendation – Spindle Oil of 46 cst at 40 degrees Celsius.

Class M and 70 (grey)
Merrow Recommendation - Spindle Oil of 32 cst at 40 degrees Celsius.

*This is not a complete list, and any high grade of spindle oil that meets the above viscosity recommendations can be used.