Bongo Fury

Hi, the offside window on my Bongo is slow to descend. It starts very slow then speeds up after it’s about 1/4 way down. It’s better on hot days. I have greased all the joints etc with white grease which seems to help for a couple of weeks and then back to slow operation. Near side works fine. Any ideas?

Have you tried lubricating the guide rails? That's the black frame that the window sits in as it slides up and down. The coating wears off. The glass starts to drag. Use a non-grease based spray. Like a silicone spray for rubber.