All seam welders are designed and built with precision bearings, a moving shaft that extends to the seam welding wheel, and conductive shoes that rotate on the shaft to pick up the current from the stationary conductors in the housing. The entire housing is sealed and contains a conductive grease or lubricant to insure long life and good electrical conduction.
This housing and shaft assembly is a very precise piece of machinery designed to last for many years with proper maintenance. Maintenance of lubrication would be one of those items.
An article on Seam Shaft maintenance is available:
CAN WORN SEAM WELDING SHAFTS BE REWORKED?
KNURL DRIVEN SEAM WELDER
Should one permit a seam welder head to run low on lubricant is an obvious answer, NO.
It would be similar to running your vehicle engine or transmission low on oil or transmission fluid. Eventually the engine freezes up or the transmission fails to shift.
No one wants to reach that point. Follow the manufacturers maintenance instructions.
The other alternative is to establish an in-house preventive maintenance procedure.
American Welding society has a standard available to serve as a guide for and in house preventative maintenance program.
AWS Standard J1.2- “Guide to Installation and Maintenance of Resistance Welding Machines”
References: RWMA Resistance Welding Manual 4th Edition
AWS J1.2 Guide to Installation and Maintenance of Resistance Welding Machines