As it's traveling? is this while the fehciel is moving or it do it as it sits still?
If it's doing it while it sits still time to Grease that pig.
Pull the carpet pannel. Under it is a access pannel to the guts of the gate. Pull it off to get access to the regulator.
The whole deal runs off a worm drive. Grease the snot out over everything. Use a grease that will stick in the heat but not super thick. If it's too think it will bog it down in the cold. I use a Synthetic Grease for wheel bearings you can pick up at Auto Zone.
If you take a rod or dowel in the passengerside latch and latch it you can operate the window to get better access.
I CANNOT MAKE IT CLEAR ENOUGH OF HOW CAREFULL YOU NEED TO BE IF YOU EXTEND THAT GLASS WITH THE GATE OPEN. Have a saw horse or something ready to suport the glass when you extend it and you have to suport it as it extends. It was not desgned to operate while being horizontal.
Watch your flangies around that regulator when it's running or even not. Big heavy spring and if something lets go your going to loose a couple digits.
Check the tracks and felts. You might find the bottoms of the tracks rusted clean off.
