Bongo Fury

My front drivers side electric window is very slow to go down. It sounds like it is straining the motor but once halfway down it shoots down no problem. Going up the window is fine too.

I seems to but rubbing on the groves, I have tried WD40 which worked for about a day but it is now back again.

Please has anybody had this before & can advise.

Cheers
Kev

i use silicon spray ,have only had to use it once and no probs since. bought from halfords but i suppose any motor shop would sell the stuff.