Seatbelt retractor issue

[Mikey]

My retractor locks during driving when the car hits a bump that is jarring enough or during spirited driving. Then it won't release and the belt continually gets a little tighter each time it happens to click another notch retracted. I have to unbuckle and let it retract fully so I can pull it back out.

Mine is a 1991. I thought I read that the retractors had an improved design in later years. Can anyone confirm what part is recommended to replace it or some other fix?