What causes weak window ascent but strong descent?

[AlyssaLee]

The reasons for weak window ascent but strong descent are as follows: Excessive dust in rubber tracks: Generally speaking, if abnormal noises occur during window operation, it is usually caused by excessive dust accumulation in the window rubber guide tracks. This increases resistance during movement, making operation less smooth. Moreover, if the dust contains particulate matter, it may produce abnormal noises. Window rubber aging: Besides dust accumulation, aging window rubber can also cause difficult window operation. In this case, simply applying lubricant can help. Spraying it on the rubber serves two purposes: providing lubrication and maintaining rubber flexibility to reduce cracking.