Originally Posted by
Mizkaki
It sometimes needs to be changed or topped off.
Look at the colour of the grease. If it's darkened and solid, I'd be changing it. You can get "gear grease" which might be the right stuff but I use "HTB" (high temperature bearing) grease, which may be overkill but none of my machines seem to mind. I just happened to have HTB in the house anyway (for the car). Don't use Singer motor lube, which will melt and run out when warm and leave the gears to grind each other into filings very quickly.