For machine Serial Numbers from 41B2910 thru 41B3009 and Serial Numbers 42B3606 thru 42B3708
These machines originally have Mobil DTE24 oil or its equivalent in the Speed Gear Box and the Feed Distributing Bracket.
The oil in the Speed Gear Box should be changed to Mobil DTE Light or its equivalent. The Feed Distributing Bracket oil should be changed to Mobil Heavy-Medium or its equivalent.
The present oil (Mobil DTE 24) in the Speed Gear Box (which also supplies the Feed Change Gear Box) has an 'Extreme Pressure' (EP) Additive. This has an excessive shear effect, which increases the Feed and Rapid Traverse clutch idle torque. Any oil with an EP Additive causes excessive and objectionable drag in the clutch plates and greatly adds to heat from friction. In addition to increasing the drag torque of the clutch, the additive will coat the clutch plates and reduce the ability of the clutch to transmit full driving torque when engaged.
To remove all traces of DTE 24 from the Speed Gearbox, flush it thoroughly with a suitable non-toxic and non-flammable solvent.
It is not absolutely necessary to flush the Feed Distributing Bracket before changing to the Heavy-Medium oil. This change is to assure fast disengagement of the sliding clutch gears.