Manual Gear Shift Lever Lost Spring Resistance for Shifting Into Reverse

My 1988 928S4 gear shift lever has lost it's 'spring resistance' and no nearly impossible to shift into reverse. After confinuous attempts, even without being able to depress the gear shift lever, I am to get it into reverse.
Does anyone have any idea what has happened? Is this a major repair?

Thank you very much.

Hello,
I learned from personal experience and from other internet posts that the 1985 and newer Borg Warner transaxles do have this problem and the gear shift jamming in gear is a symptom.

It is a major repair as the transaxle must be removed and repaired.