This is a common thing, the column shifter gets stiffer to move and then wears rapidly as the driver just yanks ever harder instead of taking it all apart for proper cleaning, lubricating and adjustment .
When I took my 69's column apart I was shocked to see the wear on the detents etc. but after cleaning it Hospital clean I used 'dustless' grease, this is cheap War Surplus as rifle grease, it lubricates really well but some how dust doesn't stick to it readily . great for old sliding sun roofs, door latches and so on .
Best of all, not only does it work as new again, it once again makes that loud GM clacking noise as it goes through each position ~ just like 1969 again !
.