Wessex Lift Boy system will not operate below 10C?

Once temp drops below 10C mechanism will not work
without giving the door a push.Have tried greasing
the latch on the winding screw.Door moves about
6inches then stalls as if door has met an object.
When Temp is above 10C no problem.
System installed on double up and over door have checked the wheels running in the side supports are
working smoothly.Any thoughts welcome