B5 PD 130 gearshift balljoint 6 speed

[shed or dead]

Hi, first post here as my '02 205k 1.9tdi has had a rather sudden fault shifting gears. For a while now it had been mildly tricky finding 6th if hesitant when shifting up. Now has suddenly affected all gears, but 3+4 to a lesser extent. I've been under the vehicle, and found that I can almost pull the linkage off the ball with no resistance, if other bits weren't in the way. Peeling back the red / orange dust cover I found no detectable means of retaining onto the ball. Now the questions.... Is this likely to be the (sole) cause of my issues? Where do i buy the repair kit? Can I sort this without dropping the engine and box (it appears so)? I'm no good at internet on phone so my apologies if posting in wrong place etc. Any help is greatly appreciated, thanks in advance, and to all who ever provided solutions, I've kept the car going this long by reading the various forums. Cheers