Hiya. A few pointers:
"In due time" doesn't sound right to me in this context. I think you should say "on time" instead. "In due time" is a rather vague expression that just means "at the appropriate time".
Also, if you say "we would like to know" you're not really directly asking them to give you that information. I would say "please could you inform us...." or "please could you let us know..." instead. That makes it clear that you want them to reply and give them that information.
Also, if you say "our truck" it means that the truck belongs to us. Are you sure that's what you mean? The truck might be a truck that doesn't belong to your company. It might be a truck that belongs to a contractor that you're paying to do the delivery.
Also, "provide" a truck sounds odd to me. Trucks aren't really something that you usually "provide". I would say "arrange" or "organise" instead.
So, with all of these wee changes, you could say "Our contractor's truck / our truck has been delayed. We would be grateful if you would please let us know the closing time of your warehouse in order to arrange for a replacement truck to pick up the goods on time."