It sounds like you have an extension spring (springs stretch along
track on sides & not on a shaft above door). If that is the case, most
likely the bearings in the cable pulleys are bad & all four pulleys
probably need to be replaced.

No you should not use grease in the rails since grease will collect
dust & dirt and actually make it harder for the rollers to move thru
the track. The door rails don't need any lubrication, but the rollers
(if they have bearings), hinges, and pulleys should be oiled on a
regular basis w/ oil made for doors or even light weight motor oil.
WD40 evaporates rather quickly & leaves a sticky residue so using it
has no benefit at all.

Doordoc