Driver and passenger Window channel issues

[mpierce9]

Hello - For some reason I can't figure out, my windows will not stay under enough pressure from the channels to stay inside the channels once rolled down. Both channels have new felt. I've adjusted the rear channel forward some to increase the holding pressure on the window to help hold it in place but that seemed to be a temporary fix. Any time these windows are rolled down they fall out of the window channel are rattle around inside the door. This also results in making it difficult to roll the window up.

The channels are original to the truck. Should I invest in new window channels? Could this be a problem with the regulator?

These are manual windows on a 1975 Chevy blazer. All windows are manual and have new felt, all other parts of the window are original.

Any advice is appreciated.

[bd]

A felt isn't properly seated in its channel or the rear channel isn't properly positioned.

Make sure the run channel felts are fully seated and the beads of the felts are locked into position inside the channels.  Verify that the forward vent window assembly is properly seated into position and tight in the door.  Make sure the adjustable rear lower channel properly engages its socket with the upper channel.  Then with the window rolled down to within 1" of its lower stop, loosen the rear channel adjusting bolts and move the rear channel forward so there is no fore-aft play in the glass.  Just remove the play, do not pinch the glass between the channels.  Occasionally, the brace that anchors the rear run channel to the inner door panel needs to be bent to gain adequate adjustment. 

Since the felts are new, spray the channels using dry silicone aerosol such as CRC 05074 Heavy Duty Silicone.  Avoid WD40 and silicone oils.  Now is a great time to liberally grease the regulator, sash channels and rollers.

[mpierce9]

Great walkthough. I'll make these adjustments and report back. Thanks for the quick and detailed reply.