Drivers side window problem. Help?

[pistolpete]

I have a 1973 911 with crank windows.
Drivers side window goes up and down but it does not stay in the front track until it gets to the top. It seems to slide towards the rear of the car as soon as I lower the window. I can slide the window front and back about a 1/2 inch with my hands which does not seem right. the window itself is not loose in the horizontal track.
Is there a spring that holds the window to the regulator keeping it closer to the front track or what am I missing?

[Evans, Marv]

An odd problem & I'm not sure I understand your description. The bottom of the window has slots with rollers that run back & forth when the window is activated. The only things I can think of would be worn out felt in the vertical window channels or maybe one of the rollers I described before is broken. It's not a big problem to unscrew the arm rest & top trim, remove the door card and have a look.

[pistolpete]

I did pull the door card off and cannot see any problem. When the window is up and I go to crank it down it goes back about a 1/2 inch and then starts to go down. There is a lot of play in the window both forward and backwards by about 3/4 of an inch. there is also some wiggle is the window

[Evans, Marv]

Weird. Only thing I can think of is a worn felt, window channel. Easy to replace.