Not sure what your oiling slides do not need to be oiled, never mentioned in this slide link
from this larger sticky
If you read the first link on slides you will see some information of adjusting the power pots on slide controls so the big slide rollers you have can get up the ramp to the flat floor.
What maybe going on is the pot is turned up to high and slide is putting pressure on slide rods and brackets holding them and a possible break of the welds of brackets. Their are pictures of this in links I have provided.
What you can do is back off on the pot in small increments and see if noise recedes, the pot should only be adjusted in small increments to operate the slide smoothly in operation of motor moving the slide, power to high will eventually cause problems, the pot is not for fast speed, the speed will always be slow but sure in operation.